Embed Size (px)
Citation preview
Wind Science and Engineering in Genoa
Wind Engineering is best defined as "the rational treatment of the interactions between wind, in the at‐mospheric boundary layer, and the man, and his manifold activities on the surface of the earth." It address‐es, in a homogeneous and interdisciplinary way, prediction and mitigation of damage caused by storms that produce, every year, numerous deaths and huge economic losses, the representation and the measure‐ment of wind and weather events linked to this, the prediction of weather and climate, the aerodynamics of buildings and transportation, full‐scale and the wind tunnel tests, the numerical simulation of the wind and its effects in regard to buildings and the environment, the static, dynamic and aeroelastic behavior of structures and their elements, the diffusion of atmospheric pollutants, the spread of fires, the transport of sand and snow, wind energy, land use planning with regard to the wind.
1. From 1976 to mid‐80s
The interest of the Istituto di Scienza delle Costruzioni at the University of Genoa towards wind was born at the end of 1976, randomly. Giovanni Solari, a student of the Degree in Civil Engineering, had asked Alfredo Corsanego and Dino Stura a thesis on tall buildings, where to apply the principles of dynamics with particu‐lar attention to seismic engineering. Simultaneously, Italimpianti proposed to Stura to assign a thesis on wind‐induced vibrations on a tripod steel chimney built in Brazil. Stura then proposed to change the subject to Solari: "A chimney is not a skyscraper ‐ he said ‐ but it's still a tall structure; also, all now study the earth‐quake, while the wind is a phenomenon just as important as not so well known."
Giving up the skyscraper was a makeshift existence. However, the study of wind seemed interesting and in‐novative above all. The decision was therefore in favor and the results disastrous. In short it was clear that the wind was not just not so studied: it was unknown in Genoa, and almost unknown in the rest of Italy, where the only one to have partially studied the problem was Alberto Castellani, the first Italian teacher of a course on Earthquake Engineering. As the course name was Earthquake Engineering and Special Dynamic Problems, Castellani had written a short report on the dynamic wind actions. Studying the Brazilian tripod starting from there was impossible, but that report was a useful starting point to find the first references in the literature.
The horizon opened out, however, was disheartening. The Wind Engineering, so some began to call this topic, was a matter born in the ‘60s and still looking for its identity. Especially critical was the approach to the problem: the wind being a random phenomenon, the literature addressed the problem through the random dynamics, a discipline unknown in Genoa and imbued, like almost all Italian schools of that era in structural engineering, with a deterministic vision. To study the random dynamics involved in turn the study of processes and probability theory. None of these subjects were given courses in Genoa at that time. No teacher at the Istituto di Scienza delle Costruzioni had expertise in these matters. Some contacts with the professors of the Faculty of Mathematics led to the closest point to the threshold of renunciation.
However, the argument continued, with the connotations of the Chinese box. Once at the inner container, probability theory, it became a race against time to study first the theory of processes, then the random dynamics, leading finally to read and understand the papers of foreign literature, up to tackle the dynamic response of structures to wind actions. Italimpianti put aside any hope of understanding the behavior of the tripod. But the argument led to a treatment of prismatic slender structures that, together with much ingenuity and inaccuracies, contained even some original findings.
After much suffering, the next choice was a rare example of stubbornness: to persevere in academic life despite the prospect of an indefinite number of years of insecurity. In a climate of austerity, then began a period of fervent research and contacts. It was dedicated to generalize the methods developed in the thesis from slender structures to those three‐dimensional, being treated on one hand, the analytical formulation,
on the other the implementation of DAWROS 1, the first computer program appeared in the literature on the dynamic alongwind response of structures of any shape, with an arbitrary number of vibration modes, and interacting dynamically with the ground.
2
Thanks to this research and the contacts established during the first international conferences on Wind En‐gineering, some inconsistencies rooted in the literature were highlighted and corrected. Above all took shape a research that led, in the early '80s, to the first closed form solution of the alongwind response of
structures 2, 3. This result, developed with reference to three structural models called point‐like, vertical and horizontal (Figure 1), is quoted in almost all papers that appeared later on the subject, and is reported also in the early texts of Wind Engineering, published in ‘80s, as the calculation method simplest and most accurate, particularly suitable for use as a base for standards and design rules.
Figure 1. Point‐like, vertical and horizontal models.
At the same time, took the field the use of methods developed in research as a tool for calculating the real structures and, on the same plane, the calculation of real structures as a source of inspiration for research adhering to engineering problems. Belonging to this study cover the Carlini stadium (Figure 2), Corte Lambruschini (Figure 3) and the Tower of San Benigno, three activities that lay the foundations for a solid relationship between Genoa and the Wind Engineering.
Figure 2. Carlini Stadium, Genoa: (a) wind tunnel model; (b) first vibration mode.
Figure 3. Corte Lambruschini, Genoa: (a) photograph, (b) wind tunnel model.
3
2. Since the mid‐‘80s early ‘90s
Between the mid‐'80s and early '90s, interest in the field of wind grows: they embrace the relationship with the codification sector, the probabilistic study of the wind, new developments on the alongwind, crosswind and torsional response of structures, stronger links with applications to real work.
The codification activity was born in 1984 when Giulio Ballio invites Giovanni Solari to be part of a Working Group of the National Research Council (CNR), responsible for drafting new instructions on wind actions on structures, asking him to deal with the chapter on the actions of wind. Solari hoses into the 10012/85 CNR Recommendations the state of the art in the matter and his closed form solution of the gust factor. Shortly after he becomes a member of the Project Team appointed to draft the Eurocode on wind actions, with an invitation to fill the gap of the Italian map of extreme winds, and to devise a calculation framework, simple but rigorous, for the dynamic response. It is the beginning of intensive Italian and European exchanges that inspire new research lines.
Research on extreme winds, carried out in collaboration with the Politecnico di Milano, is divided into three themes. The first, on the probability of occurrence of wind speed, leads to an innovative paper on the tail of
the distribution of the maximum, and hence on the speed with high return period 4, the starting point for a number of subsequent research. The second concerns the realization of a calculation program, WCLIM, which performs the probabilistic analysis of the wind data (Figure 4). The third applies the results of the previous two lines of research coming to the issue, in 1991, of the first map of the Italian extreme winds
(Figure 5) 5, 6, refined subsequently 7, it is still used by Italian standards and the Eurocode.
Figure 4. Polar (a) and maximum (b) distribution of the mean wind velocity at the Genoa Cristoforo Colom‐bo Airport.
4
Figure 5. Map of the Italian extreme winds: (a) zoning, (b) categories.
The research on the alongwind response is based on the desire to obtain an advanced closed form solution, addressed not only to analytical developments, but that could interpret the physical phenomenon of wind gusts. This aim, first supported by funding received from CNR and the Ministry of Public Education, leads to
the equivalent spectrum 8, a technique in which the actual wind speed, a random function of space and time, is modeled as the product of a deterministic function of space by a random function of time; such random function is chosen with the aim of minimizing the error made by evaluating the dynamic response of usual structures, which is dominated by the first vibration mode (Figure 6). From that comes the wind
response spectrum 9, a technique to unify wind and seismic analysis, and a substantial evolution of the
previous closed form solution 10, 11. It blends into a unitary treatment of the maximum speed, the actual pressure, the resultant force and the response: in some cases it leads to original solutions, while in others classical solutions arise as special cases. This model was first implemented in the Eurocode, later adopted
by American Standards on the wind actions on structures 12.
Figure 6. Equivalent spectrum technique: harmonic content of the actual and equivalent wind speed (a); time histories of the actual (b) and equivalent wind speed (c).
Extending the analysis of the alongwind response, caused by the mean velocity and the longitudinal turbu‐lence, to the crosswind and torsional response, caused by the lateral turbulence and the wake excitation,
leads to one of the first mathematical models of the 3‐D wind‐excited response of buildings (Figure 7) 13. Calibrated first on the results of several wind tunnel tests carried out in America, then generalized to struc‐
5
tures of any shape, it is also implemented in the calculation program WL3D 14, a new tool which becomes a little at a time essential for the activity of the Genoese group.
Figure 7. Crosswind (a) and torsional (b) wind actions on buildings.
The research results are used for applications increasingly significant and numerous, which give rise to new research addresses. The relationship with the city of Genoa is reinforced by the study of the wind actions on the container cranes of Calata Sanità (Figure 8), the Grande Bigo (Figure 9) and the decorative light poles in Corso Italia; in all these cases, besides analytical and numerical studies, full‐scale experiments are carried out.
Figure 8. Container cranes of Calata Sanità, Genoa: (a) photograph, (b) full‐scale measurements.
6
Figure 9. Grande Bigo, Genoa: (a) photograph, (b) full‐scale measurements.
Moreover, favored by the strengthening of the Italian telecommunications network, the dynamic analysis
of the wind‐excited response of the towers of Rozzano (Milan) (Figure 10) 15, San Michele Extra (Verona) and Cologno Monzese are carried out. However, especially the studies of the design wind speed on the
Messina Strait Bridge 16, of the oscillations of the Park Tower in Milan 17, 18, and of the wind risk of the Leaning Tower of Pisa 19 give fame to the Genoese research. The study of the Messina Strait Bridge,
made possible by the probabilistic modeling of the wind speed with high‐return period 4, gives rise to the first collaboration with Corrado Ratto and his research group at the Department of Physics (DIFI) of the University of Genoa, in the field of the numerical modeling of the wind (Figure 11). The numerical and the experimental analyses of the Park Tower (Figure 12) allow the first relevant applications and tests of the
models for calculating the 3‐D wind‐excited response 13, 14. The Leaning Tower of Pisa (Figure 13) is an ideal benchmark to formulate a new model for the aerodynamic identification of structures 20.
Figure 10. Tower of Rozzano: (a): photograph, (b) wind tunnel model (c) vibration modes.
7
Figure 11. Design wind speed on the Messina Strait Bridge: (a) model of the bridge, (b) simulation of the mean wind speed.
Figure 12. Park Tower in Milan in 1933 (a) and 1992 (b); measurement of the top acceleration (c).
Figure 13. Tower of Pisa: (a) model, (b) wind tunnel tests.
8
3. From the beginning to the end of the ‘90s
Between the beginning and the end of the '90s, Giuseppe Piccardo and Luisa Carlotta Pagnini join Giovanni Solari in the study of the wind, creating the nucleus of a research group straining to expand its interests. Such interests, concerning the dynamic and aeroelastic response of the slender elements and structures, the instability and bifurcation of the dynamic equilibrium, the propagation of uncertainties and the safety, give rise to several research contracts that, on the one hand, provide a robust support to the relationships between basic and applied research, on the other, enhance cooperation with DIFI on wind modeling. Genoa also assumes a leading role in the management of institutional activities taking place both nationally and internationally on the issue of Wind Engineering.
The research on the 3‐D actions and response of slender elements and structures gives rise to a unified
mathematical model, including fluid‐structure interaction 19, 2 . It also leads to a novel method, based on
the use of Laplace transforms and state space 19, to evaluate the critical speeds of incipient aeroelastic instability. The classic conditions for galloping, divergence and flutter are obtained as special cases. Above all this creates the bases for developing two new research lines aiming to become leading Genoese issues.
The first research line concerns the response of the slender elements and structures, and the extension of the classical gust factor technique, by its nature limited to the alongwind direction, to the crosswind and
the torsional motion. Thanks to the generalized gust factor technique 21, 22, the equivalent static actions in the three generalized directions are assigned as the product of the mean static alongwind force by as many dimensionless parameters, the alongwind, crosswind and torsional gust factors, expressed in closed form. The previous solutions, limited to the alongwind response, are found in the form of special cases and further improved (Figure 14).
Figure 14. Generalized gust factor technique: (a) structural model; (b) scheme of actions and response; (c) comparison between the theoretical and experimental analysis of a chimney.
The closed‐form solutions allow to easily tackle advanced topics such as the propagation of uncertainty and reliability. Developing the analytical solutions in Taylor series leads to derive expressions of the statistical moments of the response that take account of the uncertainties in model parameters and errors, providing
information on the robustness of the solution 25, 26. This is a preparatory step towards the study of the wind risk, a new research line that produces a series of papers on the safety of structures in relation to the ultimate limit states and, most importantly, to the serviceability limit states related to the physiological tol‐erability of motion. They shed light on the role of the uncertainties inherent damping and even more of the
distribution of the extreme wind speed 27‐29.
In parallel Giuseppe Piccardo opens a second line of research in collaboration with Angelo Luongo. By com‐bining the expertise of the University of L'Aquila on nonlinear dynamics and perturbation methods with the Genoese knowledge on the dynamic and aeroelastic response of slender elements and structures, a broad program of studies arises on the nonlinear behavior of iced cables, one of the most classical themes in Wind Engineering. Applying the method of the multiple scales and integrating the Lagrangian equations of motion, first the critical conditions of galloping are analyzed taking into account two translational degrees of freedom (Figure 15), then the role of the torque and of the mean wind force is investigated; the post‐
critical conditions of galloping are also studied 30 ,31 .
9
a1
a2
B
=0.1V=12.3 m/s
(a)
0 4E-4 8E-4 1.2E-30
2E-4
4E-4
6E-4
8E-4
D
Initial conditions:a1=1.2 E-03a2=0.8 E-03
q2
q1
(b)
-1.4E-3 -7E-4 0 7E-4 1.4E-3-1.4E-3
-7E-4
0
7E-4
1.4E-3
Stable orbit
Figure 15. Post‐critical behavior of iced cables: (a) curve of the phases, (b) transient motion.
Around the collaboration between Genoa and L'Aquila, it also strengthens scientific relationship with the Politecnico di Milano, the University of Rome La Sapienza and the University of Messina. Centered on the general problems of dynamics, it leads to one of four projects of national Italian interest co‐financed by MURST (Ministry of University and Scientific and Technological Research) in the structural field, in the first year of this new initiative. Through continuous developments, the project and the research team are still operating, and indeed they are one of the rare examples of activities supported by the Ministry, without interruption, for over a decade.
At the same time, Italy is pervaded by a profound crisis in the construction of major civil works. It reflects on the activity of the research team, depriving it of one of its peculiarities: the wind‐excited analysis of the large structures. Conversely, it develops a new activity concerning research contracts in the broad field of constructions and in the subject of climatology.
The contract with the Italian manufacturers of lighting poles and monotubolar towers, born from the need to understand the behavior of a structural type as widespread as delicate, and to unify national production around a shared method of calculation, is a unique opportunity to implement, develop and test many of the methods developed by the research team. It also leads to a campaign of full‐scale measurements of the
damping 32 (Figure 16), to a new model of the dynamic response of slender structures with concentrated
masses 33, and to a unified calculation procedure applied on a national scale by the designers of this structural type 34.
log-
decr
emen
t(%
)
displacement (m)
disp
lace
men
t(m
)
channel 1
time (s)
log-
decr
emen
t(%
)
displacement (m)
disp
lace
men
t(m
)
channel 1
time (s)
Figure 16. GEO Tower: (a) full‐scale measurements; (b) analysis of the damping.
10
On the basis of this activities and of the research on the physiological tolerability to motion, a new research collaboration also starts with Yukio Tamura, leading Luisa Carlotta Pagnini to spend a period of study at the Tokyo Polytechnic University. This period, funded by the Italian C.N.R. (National Research Council) and the J.S.P.S. (Japan Society for Promotion of Science), is devoted to a technique in that epoch innovative: the use
of GPS as a tool for the distributed monitoring of tall buildings in urban areas (Figure 17) 35.
Figure 17. Monitoring of a steel lattice tower using GPS, Japan.
The research on climatology, linked to studies on the probability of wind occurrence 36, 37, develops since 1995 around several contracts aimed at realizing the Meteo‐Hydrological Center of Liguria Region
(CMIRL) (Figure 18) 38. This project involves, in addition to Civil Protection, DIFI for weather forecasting, the Interdepartmental Centre for Environmental Monitoring (CIMA) for hydrological problems, and DISEG for climatological studies. In this way, an interdisciplinary collaboration arises in which scientific research and service activities for community intersect, creating a structure among the most modern and efficient at the national and international level. When in 2001, exhausted its experimental period, CMIRL is absorbed by the Regional Agency for the Liguria Environmental Protection (ARPAL), with the hiring of 17 permanent people who grew up in the University of Genoa, the research unit in Wind Engineering has definitely gained new skills and developed a strong partnership with DIFI. The realization of the wind map of Liguria Region
(Figure 19) 39 and the feasibility study of a wind farm on the breakwater of Genoa (Figure 20) fall within that context.
METEOSAT dataHydrological elaborations
Statistical elaborationsValidation of meteorological data
Meteorological forecastMeteorological attention Validation of meteorological data
Statistical elaborations
Meteorological forecast
Statistical elaborationsValidation of meteorological data
Hydrological elaborationsHydrological attention
Meteorologicalsection, Genoa
Hydrologicalsection, Savona
Climatologicalsection, Genoa
Meteorological forecastMeteorological attention Hydrological elaborations
Civil Protection ServiceLiguria Region
Figure 18. Organizational and functional diagram of CMIRL.
11
1380000 1400000 1420000 1440000 1460000 1480000 1500000 1520000 1540000 1560000 1580000(m)
4860000
4880000
4900000
4920000
4940000
(m)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 (m/s) (m/s)
1380000 1400000 1420000 1440000 1460000 1480000 1500000 1520000 1540000 1560000 1580000(m)
4860000
4880000
4900000
4920000
4940000
(m)
10 14 18 22 26 30 34 38 42 46 50
Figure 19. Map of the mean wind velocity in Liguria at 10 m height above ground: (a) mean value, (b) value with 50‐year return period.
Figure 20. Genoa breakwater: (a) best sites to install wind turbines; (b) wind measurements.
The role of Genoa in the management of research and education in Engineering Wind increases since 1995, when Giovanni Solari is elected as the coordinator of the European and African Region of the International Association for Wind Engineering (IAWE). In this role, in 1997, he presides the 2nd European and African
Conference on Wind Engineering (2 EACWE) 40 and, along with Corrado Ratto, the Satellite Workshop on
Wind Energy and Landscape (WEL) 41 (Figure 21), both held in Genoa. With about 400 participants from all over the world and many civic events centered on the wind, Genoa is mobilized around these initiatives further reinforcing its ties with Wind Engineering (Figure 21). Several national and regional institutions also help to open the conference, for the first time, to numerous Eastern European delegates, giving rise to a turning point in European scientific cooperation.
Figure 21. (a) 2 EACWE, Genoa, 1997; (b) WEL, Genoa, 1997.
12
Figure 22. Some titles of articles in the print media for 2 EACWE, Genoa, 1997.
In 1998 Solari becomes a Co‐Editor‐in‐Chief of Wind & Structures (Figure 23) 42 and in this role he co‐chairs some international conferences focused on this journal (Figure 24) 43, 44. In 1999 he is elected President of the Italian National Association for Wind Engineering (ANIV) and Chairman of the Committee to provide a renewed organizational structure to IAWE, an association rapidly growing. In 2000, with Giuseppe Piccardo and Luisa Carlotta Pagnini, Solari organizes and chairs the 6th National Conference of
Wind Engineering 45 and, above all, the first International Advanced School on Wind‐Excited and Aeroelastic Vibrations of Structures (Figure 25), funded by European Community; still an inspiration for many other schools traveling throughout the world, it brings in Genoa, as lecturers, the most outstanding scientific personalities, as students, graduate students, professors and researchers from every continent. In the same year, Genoa is home to the first academic Italian course in Wind Engineering.
Figure 23. Wind & Structures, an International Journal, Techno Press, Seoul, Korea.
Figure 24. Wind & Structures International Symposia.
13
Figure 25. International Advanced School on Wind‐Excited and Aeroelastic Vibrations of Structures, Genoa.
4. The first decade of the third millennium
Since early 2000, the research group in Wind Engineering is enriched with new members, Luigi Carassale, Maria Pia Repetto, Federica Tubino and Andrea Freda, with the contribution of various Italian and foreign students who spend periods of study in Genoa, and with scientific collaborations ever closer with national and international centers. On the one hand, the study of the dynamic and aeroelastic response of slender elements and structures continues. On the other hand, new lines of research open up, related to the Proper Orthogonal Decomposition (POD), the non‐linear and non‐Gaussian analysis by Volterra series, the damage caused by fatigue, the representation and simulation of turbulence using spectral models, the response of long span bridges, the aerodynamics of bluff‐bodies, the multi‐scale modeling of wind fields, monitoring and structural identification. It expands also the activities relating to the contracts. The public works restart and return to be focal the analyses of the dynamic response of large structures. The commitment in codes restarts and grows the involvement in the management of research and education on the wind. There is a new laboratory for dynamic tests on real structures and starts the construction of a modern wind tunnel.
The study of the slender elements and structures reflects the addresses of international research, oriented to develop models tailored to the different effects induced by the wind. The research unit thus return to its treatment of the generalized gust factor and a novel technique is developed by which the equivalent static actions that cause individual effects are given by the product of the mean alongwind force by dimension‐
less parameters, the gust effect factors 46, expressed in closed form. The previous solutions are found as particular cases and further refined. A new classification criterion is formulated, based on the response of
different construction types 47. A class of equivalent static actions is introduced, among which the first
model that reproduces, with a single load distribution, the full pattern of the loading effects 48.
The study of nonlinear dynamic behavior of iced cables develops previous research 49 and gives rise to two new lines, again in collaboration with the University of L'Aquila. The first concerns the formulation of an innovative mechanical model of the cable; combined with a simplified model of the aerodynamic forces,
it allows to investigate the role of twist on galloping 50. The second addresses the issue of multi‐modal galloping, investigating the influence of higher modes on the critical and non‐linear oscillations (Figure 26)
51, 52, 53.
14
tr
Ca
detCa
c22
0cr<DH
0cr>DH
(a) (a)
(c)
(c) (d)
(d)
STABLE (b) (b)
(a)
detCa0
0cr
DH
(a)-(a)
(b)-(b)
0cr
detCa
DH
0
(c)-(c)
0cr
trCa
DH
0c22
(d)-(d) 0
cr
trCa
DH
0 c22
(b)
Figure 26. Analysis of the critical galloping speed in the non‐linear field.
The research on POD stems from the study of the similarities of its applications in aerodynamics, where it is used from the ‘70s as a proper covariance transformation, and in Monte Carlo simulation of random fields, where is used as a proper spectral transformation from the ‘80s.
On the one hand, POD is revalued by defining the prerogatives of its use in discrete and continuous form as
well as in time and frequency, as a proper covariance and spectral transformation 54. Its properties are detailed in the Monte Carlo simulation, by setting up a system of filters that reproduce the correlation
structure of the random field 55. The proper covariance and spectral transformations are framed in the series expansions of Karunhen and Loeve, giving unity to the representation mono / multi‐variate processes
with finite / infinite energy 56, 57.
On the other hand, the Double Modal Transformation (DMT) is developed, a method based on the expan‐
sion of the response by modal analysis, and of the loading through POD 54,58 . Using DMT, the response is expressed as a double series of the structural and loading modes, weighed by means of principal coordi‐nates of the structure (SPC) and the loading (LPC). In principle, each SPC is excited by each LPC. In fact, due to the modal truncation and quasi‐orthogonality of the structural and loading modes, only a few SPC are excited by a few LPC (Figure 27). This technique has already had a wide dissemination.
Figure 27. Structural and spectral loading modes.
Meanwhile, during his doctoral thesis, carried out by spending a long period of study at the University of Notre Dame in Indiana, led by Ahsan Kareem, Luigi Carassale opens a new branch devoted to the analysis of the non‐linear and non‐Gaussian random response of structures using the Volterra series. The POD of the loading allows one to extend the formulation from single to multi‐degrees of freedom systems (Figure 28)
59, 60. The joint use of the calculation techniques developed by Piccardo in the nonlinear deterministic field and by Carassale in the random field, offers new perspectives for a broader vision of two subjects
strictly separated in the literature 61, 62.
15
Figure 28. Volterra series expansion: (a) battery of filters, (b) power spectrum of the output process.
Stimulated by the growth of damage and collapses due to wind‐induced fatigue and by the lack of engi‐neering calculation methods, research on this topic arises during the PhD thesis of Maria Pia Repetto. First,
the fatigue is studied using the hypothesis that the stress process is narrow band 63‐65. Subsequently, taken note of caution excess due to this hypothesis, it is developed a bi‐modal model of the spectral con‐
tent of the stress 66; parallel, two simple models are formulated, indicated with the acronym PC, and
PVC, which provide an upper and lower bound of the damage 67 (Figure 29). Finally, removing the classic hypothesis of neutral stratification of the atmosphere, the formulation is extended to the stable and unsta‐
ble regimes 68. Overall, the treatment gives rise to the first complete model for the calculation of the fa‐tigue induced by the wind on the structures. On the one hand, the model is checked against a large collec‐
tion of damaged and collapsed structures (Figure 30) 69. On the other, until it is developed to formulate
the first closed form solution of the alongwind induced fatigue 70, 71.
0
0.001
0.002
PCijd
refU m/s
0
0.001
0.002
j[Mpa] refU m/s
PVCijd
0
0.001
0.002
j[Mpa] refU m/s
ijd
0
0.001
0.002
PCijd
refU m/s
0
0.001
0.002
PCijd
refU m/s
0
0.001
0.002
PCijd
refU m/s
0
0.001
0.002
j[Mpa] refU m/s
PVCijd
0
0.001
0.002
j[Mpa] refU m/s
PVCijd
0
0.001
0.002
j[Mpa] refU m/s
PVCijd
0
0.001
0.002
j[Mpa] refU m/s
ijd
0
0.001
0.002
j[Mpa] refU m/s
ijd
0
0.001
0.002
j[Mpa] refU m/s
ijd
Figure 29. Histograms of fatigue damage: (a) PC method, (b) bi‐modal method, (c) PVC method.
Figure 30. Real and simulated damage due to the fatigue induced by the wind.
16
The doctoral thesis of Federica Tubino is the starting point for two lines of analysis also stimulated by the activities carried out for the bridge over the Strait of Messina: the representation of turbulence, a theme already present in many previous studies, and the aerodynamic behavior and aeroelasticity of long span bridges. Both draw inspiration from the remarkable research on the POD.
The study of the representation of the turbulence stems from the formulation of the first comprehensive
model of the uncertainties of the parameters 72, also incorporated in Eurocode 1. Using this model and the results of the research on POD, the turbulence is schematized by two systems of principal coordinates
derived by applying the proper covariance and spectral transformations 73. The turbulence modes are ob‐
tained in closed form 74, giving rise to enormous advantages in the numerical Monte Carlo simulation of the turbulence fields. The correlation between different components of turbulence, usually neglected, is
recovered through a double POD series expansion 75.
The study of the aerodynamic and aeroelastic behavior of long span bridges combines the 3‐D models de‐
veloped by the research group 21, 22 with the POD representations of the turbulence. New relationships are developed between the aerodynamic admittance functions and the flutter derivatives 76. Above all it is introduced a totally innovative concept, still liable of large developments: using the DMT, an effective ac‐tion is defined as the joint composition of the load by means of the only POD modes of which the structure
is affected (Figure 31, 32) 77, 78. Because typically the effective portion of the load is small, the normal criteria of spatial and temporal discretization are often disproportionate to the actual needs. This principle goes beyond the scope of the wind where it is formulated, and invests any problem of dynamic excitation,
first of all the seismic motion 79.
10-3
10-2
10-1
100
101
102
0
1
2
3
4
5
6
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0- 2 0
- 1 5
- 1 0
- 5
0
5
1 0
1 5
2 0
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0- 2 0
- 1 5
- 1 0
- 5
0
5
1 0
1 5
2 0
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0- 2 0
- 1 5
- 1 0
- 5
0
5
1 0
1 5
2 0
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0- 2 0
- 1 5
- 1 0
- 5
0
5
1 0
1 5
2 0
Figure 31. Effective turbulence for the Messina Strait Bridge: harmonic content of the real and effective turbulence (a); time history of real (b) and effective turbulence (c).
Figure 32. Coherence function of the real (a) and effective (b) turbulence.
The doctoral thesis of Andrea Freda returns to the theme of the aeroelastic response of slender elements, in the light of recent evidence concerning the unstable phenomena of yawed cylinders. Applying a modified
quasi‐steady theory, these phenomena are justified, for the first time, in analytical form (Figure 33a) 80.
17
On the momentum of these results, of similar studies conducted in Japan, and of increasingly close rela‐tions between Genoa and the Centre Of Excellence (COE) on Wind Effects on Buildings and Urban Areas, Tokyo Polytechnic University, of which Giovanni Solari is a member the Scientific Committee, Freda spends some periods of study in Japan, funded by JSPS and COE, during which he conducts various wind tunnel tests on rigid and aeroelastic models of yawed cylinders (Figure 33b).
plane
plane
2e
U
1e
3e plane
Figure 33. Yawed cylinders: (a) quasi‐steady theory; (b) wind tunnel tests.
The aerodynamic study of bluff‐bodies leads to a deeply innovative search during which, starting from the usual definitions of symmetry and skew‐symmetry of the mean wind actions on a body immersed in a fluid, new conditions of statistical symmetry are formulated about the statistical moments and the covariance
eigenfunctions of the pressure field 81. This approach clarifies several doubts and inconsistencies in the literature of the wind tunnel tests.
Following the path taken in previous years, drawing on the recovery of the great works and trusting in a larger group, growing relationship are established with the public and private agencies needing to solve problems in which Genoa has been recognized expertise at local, national and international level. On one hand, there is a proliferation of the analyses of territorial and infrastructural problems, on the other, large structures are increasingly being studied by the research group in respect with the actions of the wind.
The distinctive feature of the contracts on territorial issues and infrastructures is increasing collaboration with the DIFI, embodied in the creation of WIND_Lab, a laboratory of Wind Engineering and Physics that incorporates, probably for the first time, the skill needed to cover the wind phenomenon from meteorology to its effects on buildings, environment and territory; as part of this general view, a multi‐scale model of the wind fields in complex terrain is formulated, which combines the skill of DIFI on mass consistent models of synoptic‐scale phenomena, with those of DICAT on POD techniques and Monte Carlo methods for the
simulation of turbulence 82.
On the basis of this collaboration, DICAT and DIFI together study the routes at the airport of Albenga, on behalf of ENAV (National Flight Assistance Agency), the definition of the design wind on the Messina Strait Bridge, and the wind hazard of many high‐speed railway lines ‐ the Roma ‐ Napoli, Napoli ‐ Salerno, Milan ‐ Bologna, Bologna ‐ Florence, Milan ‐ Novara ‐ commissioned by RFI (Italian Railway Company). These con‐tracts are once again the starting point for research on advanced topics: the study of the wind at the
Albenga Airport leads to an original method to simulate nonstationary wind fields (Figure 34) 57 and an indicator to estimate hazard of flight operations 83; the Messina Straits Bridge is the testing ground for a
new simulation algorithm (Figure 35) 84, 85 and to introduce the concept of effective turbulent 77; the analysis of the Rome –Naples, carried out within the European project Aerdynamics in Open Air (AOA),
leads to a general model applicable to any railway line (Figure 36) 86, 87. During this project an original method is also formulated for the short term prediction of the wind, using a conditional probabilistic tech‐
nique (Figure 37) 88.
18
0 1000 2000 3000 4000 5000x [m]
-8
-4
0
4
8
VY [
m/s
]0 1000 2000 3000 4000 5000
x [m]
-4
-2
0
2
4
VZ [
m/s
]
(c)
(d)
Figure 34. Airports of Albenga: (a) mean wind velocity field, (b) non‐stationary simulation.
Figure 35. Messina Strait Bridge: (a) rendering, (b) Monte Carlo simulation of the wind field.
12
34
5
-10
0
10
H.a
.g. [
m]
20
25
30
35
40
45
V -
MA
SSIM
I [m
/s]
10
15
20
25
30
V -
ME
DI
[m/s
]
Figure 36. Rome‐Naples HV / HC railway line: (a) simulation domain, (b) probabilistic analysis.
0.51
0.10.01
0.001
0.0001
1e-006
1e-005
1
Vmax
V ,max
Figure 37. Short‐term forecast: (a) conditional probability, (b) conditional simulation.
19
The experience in the analysis of the behavior of structures under wind actions is enriched with increasingly diverse test cases. They comprehend the Brancusi's Endless Column, Romania's national monument and world heritage by UNESCO, studied with the Romanian National Institute for Building Research and the
CRIACIV (Figure 38, 39) 89, the Enelpower thermoelectric power stations of Piacenza, Ravenna, La Spezia and Syracuse (Figure 40), covered by aerodynamic fairings to improve the visual impact, but very sensitive towards the wind, the Enelpower stacks of Ballylumford (Ireland) and Syracuse (Figure 41), making use of tuned mass dampers to counteract the vortex shedding, telecommunications towers with masking cylinders (Figure 42), the Italian Aerospace Agency's Vega launcher, sensitive to the wind before launching, the cable‐stayed footbridges in Siena Palermo (Figure 43), submitted to wind tunnel tests to optimize the shape, the skyscrapers of Isozaki, Hadid and Libeskind in the historic district of the Fair of Milan, distinguished by their tall, slender and unusual form for the Italian tradition (Figure 44), the new pavilion at the Fair of Genoa, with a wing‐shaped overhang jutting out over the sea (Figure 45), the study of the design wind speed at the high‐speed railway station of Reggio Emilia and the Fuxas’ “Nuvola” at Eur, Rome. The pedestrian footbridges analyzed by Giuseppe Piccardo and Federica Tubino open the doors to a new line of research centered on
the transit of pedestrians and crowds over an extremely deformable structural type 90, 91. The study of the skyscrapers at the Fair of Milan is an opportunity to carry out more general assessments that focus on
the issues and the evolution of skyscrapers 92, 93.
Figure 38. Brancusi's Endless Column, Tirgu Jiu, Romania: (a) construction, (b) recovery, (c) present state.
Figure 39. Brancusi's Endless Column, Tirgu Jiu, Romania: Wind tunnel tests.
20
Figure 40. Wind tunnel tests on models of the Enelpower thermoelectric power stations of: (a) Piacenza, (b) Ravenna (c) La Spezia.
Figure 41. Enelpower power plant of Syracuse: (a) photograph, (b) tuned mass damper.
Figure 42. Telecommunication tower: (a) antennas in the open air, (b) masking cylinder; (c) porous cover cylinder.
21
Figure 43. Pedestrian cable‐stayed footbridge of Siena (a) and Palermo: finite element (b) and wind tunnel (c) model.
Figure 44. Historic district of the Fair of Milan: Isozaki, Hadid and Libeskind towers.
1
2 3 4
65
7 8 9 10 11
12 13
14 15 16
17
1
2 3 4
65
7 8 9 10 11
12 13
14 15 16
17
Figure 45. B Pavillion of the Fair of Genoa.
After a period of stasis, the regulatory efforts re‐start. Giovanni Solari becomes a member of the CNR Committee on standards and coordinates the preparation of new instructions on the actions and effects of wind on structures. He becomes a member of an international committee that compiles the state of the art
and provides guidelines on the actions of wind 94. He assumes the chairmanship of the Subcommittee SC1, Actions on structures, of the Structural Engineering Commission (CIS). In 2003, the University of Genoa and Milan Polytechnic organize, with the central role of DISEG and DIFI, the first second level university Master in Wind Engineering (Figure 46). The more important effort, however, comes from the International Association for Wind Engineering (IAWE). In 2003, Giovanni Solari is elected as the president, then he ap‐
22
points as Secretary General Giuseppe Piccardo and settles in Genoa, the secretary of the association (Figure 47). It is the beginning of a period of great intensity, in which Genoa is the barycentre of the international
community in Wind Engineering 95, 96.
Figure 46. Secon Level University Master in Wind Engineering.
Figure 47. IAWE: (a) act of foundation, (b) website.
The dynamic testing is divided into two strands that respectively deal with full‐scale measurements and wind tunnel tests, both of which are developed with the central role of Luigi Carassale.
Carassale creates a laboratory with equipment for simultaneous acquisition of signals of accelerometers, position and displacement sensors, strain gauges and anemometers; hardware and software tools are de‐veloped for different types of dynamic tests and the long‐term monitoring; instrumentations for the me‐chanical excitation of structures are also developed. Parallel the analysis of the measures strongly grows; it uses the expertise on the processes, and in particular on the POD, applying this technique to an original
identification of structures 97. Thanks to these activities, relevant developments are carried out in the monitoring of buildings exposed to the wind develops and, more generally, in civil and industrial construc‐tions undergoing actions and effects of anthropogenic and natural type. Among the first stands the perma‐nent monitoring of a light pole in Vado Ligure (Figure 48), now a reference point to calibrate and verify models developed by the group. Among the latter stands out various measurement campaigns conducted in the Middle East, on behalf of Fisia Italimpianti, on desalination plants in Ras Laffan, Shuweihat and Taweelah (Figure 49).
23
Figure 48. Light tower of Vado Ligure: (a) photograph, (b) sonic anemometer; (c) system for the transmis‐sion of data.
Figure 49. Desalination plant of Shuweihat, United Arab Emirates (a) and centrifugal pump under dynamic measures (b).
The wind tunnel (Figures 50, 51), which opened October 28, 2008, is one of the initiatives promoted by WIND_Lab, and represents the result of a long process of planning and construction began in 2002 and aimed at building a modern facility for model tests. The tunnel is a closed circuit and is equipped with a test chamber 8.8 m long, 1.35 m wide 1.65 m high. Thanks to a fan and an engine with a power of 132 kW, the velocity of flow in the test chamber reaches about 40 m/s. The tunnel has some innovative features con‐cerning the expansive corner areas, a high coefficient of contraction combined with a treatment of the flow through networks in the stagnation chamber, and a flow of high quality, which is characterized by consider‐able homogeneity, low level of turbulence and high thermal stability. The test chamber has two areas of measurement. The first, at the entrance, is designed to test aerodynamic and aeroelastic sectional models in homogeneous laminar flow or turbulent made using grids. The second, in the end, is aimed at civil and environmental measures carried out by simulating the atmospheric boundary layer with surface roughness
and passive and active devices 98.
24
Figure 50. Wind tunnel: (a) rendering, (b) execution of building works.
Figure 51. Wind tunnel: (a) during assembly, (b) finished plant.
The wind tunnel is a summary of the vision of reaching out, firstly, scientific and educational purposes in‐spired by academic and institutional aims and, secondly, a support activity for public and private, aimed at solving problems in a real industrial spirit capable of producing funds to reinvest in equipment, basic re‐search and technological development.
5. Recent Developments
The most recent activities undertaken by the Research Group in Wind Engineering relate in various threads in implementation and / or programming. They have some common denominators: to establish an increas‐ingly close collaboration in Italy and around the world to strengthen the leader role of the group in the wind field; to broaden skills in an interdisciplinary form; to acquire new quality and motivated young re‐searchers; to develop existing laboratories and implementing new, enhancing operational spectrum; to in‐crease in public and private sectors, the role of the group, now known for its ability to solve complex prob‐lems of technical and social importance; to increase the contracts and conventions to reinvest the proceeds in basic research, introduction of new young and laboratory equipment, to determine an optimal ratio be‐tween basic and applied research, and education.
Addressing in greater detail the lines undertaken, three new fellows and research contractors, Marco Tizzi, Marina Pizzo and Patrizia De Gaetano, with specific expertise in meteorology, atmospheric physics, envi‐ronmental science and geophysics, become part of DICAT; integrated into the existing group, they help to create a homogeneous research unit that aims to continue, in the same place, the activities developed by DICAT and DIFI in different locations. Parallel the strategic decision is taken to stabilize this new branch of activity by creating a competition for a permanent research position in the GEO/12 sector, Physics and Oceanography, entirely paid on the funds of the research group. Massimiliano Burlando, the winner of this
25
competition, takes service from December 1, 2010 and is now the responsible for enhancing the modeling of the wind; he has to bring expertise in oceanography likely to develop in DICAT new lines of research on the interaction between the wind and the waves; above all he must strengthen the energy sector, estab‐lishing strong links between the study of wind potential, the choice of turbines, and their design.
The European Project Wind and Ports (2009‐2012) is part of the cross‐border Cooperation Program Italy ‐ France Maritime, carried out in collaboration between the Port Authority of Genoa, Savona, La Spezia, Livorno and Bastia, with the Research Group on Wind Engineering in the guise of scientific single actuator
(Figure 52) 99, 100. The project is conducted under the supervision of Giovanni Solari, Maria Pia Repetto and Massimiliano Burlando, and with the participation of Marco Tizzi, Marina Pizzo, Patrizia De Gaetano and Mattia Parodi. It aims to assess the hazards of port areas in relation to the wind through four lines: 1) the creation of a network of sensors for measuring wind in ports (Figure 53), 2) the statistical analysis of the wind (Figure 54), for long‐term planning, 3) the prediction of the wind in the medium term (Figure 55), for the organization of port activities, 4) the prediction of the wind in the short term (Figure 56), for warning and safety of workers and various components of the ports. The project is achieving great success with the active involvement of all ranks in the High Tyrrhenian Sea area (admiralty, terminal operators, pilots, work‐ers, unions, ...). The results obtained are so important that the partners of this initiative are finalizing port prospects in a number of new European projects that, starting from the knowledge of the wind, may deepen its consequences. Under this point of view, projects are currently underway for the safety of port structures, the interaction between wind and wave action to ensure safe operation of entry and exit of ves‐sels from the ports, the study of wind potential to make port wind farms, the dispersion of pollutants and dusts.
LivornoLivorno
BastiaBastia
GenovaGenovaSavonaSavona
Vado LigureVado Ligure
Mar Tirreno
La SpeziaLa Spezia
LivornoLivorno
BastiaBastia
GenovaGenovaSavonaSavona
Vado LigureVado Ligure
Mar Tirreno
La SpeziaLa Spezia
Figure 52. Project Wind and Ports: (a) logo, (b) partners.
Figure 53. (a) Location of instruments in the Port of La Spezia; (b) anemometer tower in the Port of Livorno.
26
Figure 54. Mean wind speed in the Port of Genoa, at 10 m height above the ground.
Figure 55. Two‐day forecast of the mean wind speed in the Port of Genoa: resolution with grid step 230 m (a) and 80 (b).
Figure 56. Port of La Spezia: (a) 30‐minute forecast of the mean wind speed, (b) forecast reliability index.
The study of the wind in the Bay of Weymouth (Figure 57) in support of the Italian sail national team that has participated in the Olympic Games of London, U.K, 2012, carried out in collaboration with the Meteo‐Hydrological Centre of Liguria Region (CMIRL), the Institute of Atmospheric and Climatologic Sciences of the National Research Council (CNR) and the Institute of Marine Sciences of CNR, is an investment aimed at opening a new collaboration channel with the Italian National Olympic Committee (CONI) concerning all the sport competitions where the wind has a dominant role.
27
Figure 57. Bay of Weymouth: (a) Google‐Earth view; (b) mean wind filed.
The wind tunnel is the real challenge of the Research Group for its future. Opened October 28, 2008, 2009 was entirely dedicated to the verification and calibration of the facility (Figure 58), conducted by Luigi Carassale with the collaboration of Andrea Freda. Since early 2010, the tunnel is operational (Figure 59) and, also thanks to the involvement of many PhD students – Michela Marrè Brunenghi, Federico Percivale, Stefano Sandon and Mattia Parodi ‐ is already working on several contracts from many of which derive new research lines focused on bluf‐body aerodynamics and structural aeroelasticity. Among these activities are
worth noting the study of the wind on Erzelli Hill 101, commissioned by Genova High Tech for the installa‐tion of the new Technology Park, including the Faculty of Engineering of the University of Genoa (Figure 60), a similar study of the Portello Quarter (Figure 61), the analyses of the pedestrian walkways on Viale Serra (Figure 62) and Via De Gasperi (Figure 63) in Milan, the "Table" (Figure 64) and "Sail" canopies of Piaz‐za Portello (Figure 65 ), also in Milan, on behalf of Ipermontebello, the aeroelastic analysis of the
megaframes 102 (Figure 66) and of the comfort of the terraces (Figure 67) of Varesine Towers, in Milan,
on behalf of Hines, the study of the dynamic and aeroelastic behavior of the Marchetti viaduct 103 (Figure 68), on Highway Milano ‐ Novara, on behalf of Ativa.
Figure 58. Calibration tests for the wind tunnel.
28
Figure 59. Tests in the wind tunnel on a boat and two bridge decks side by side.
Figure 60. Technology Park of Erzelli Hill, Genoa.
Figure 61. Portello Quarter, Milan.
29
Figure 62. Pedestrian walkway on Viale Serra, Milan.
0 100 200 300 400 500 600
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
t (s)
a (m
/s2 )
1
2
Figure 63. Pedestrian walkway on Via De Gasperi, Milan.
Figure 64. "Table" canopy in Piazza Portello, Milan.
30
Figure 65. "Sail" canopy in Piazza Portello, Milan.
Figure 66. Megaframe of Varesine Towers, Milan.
Figure 67. Terraces of Varesine Towers, Milan.
31
Figure 68. Aeroelastic sectional models of the deck of the Marchetti viaduct: (a) away from the ground, (b) near the ground, developing the layer in correspondence of the ceiling of the wind tunnel.
Also taking cue from the wind tunnel, the Research Group has gained the confidence to manage a full range of issues concerning the wind phenomena, with the only shortcoming of the use of Computational Fluid Dynamics (CFD). In light of this remarks, Luigi Carassale has opened a new line of research in CFD, with the involvement of Alessandro Bottaro, some colleagues from the University of Pisa, and a new research fellow, Joel Guerrero. In collaboration with Massimiliano Burlando it is also in progress an integrated development of meteorological models and CFD simulations, to analyze the wind field in complex terrain; using the moni‐toring network under realization in this area and ongoing wind tunnel tests, Erzelli Hill will be used as a ref‐erence test case (Figure 69). In this way, a long process of planning for the activities of the Research Group is almost completed.
Figure 69. CFD model and simulation of a wind field on the Hill Erzelli.
At the same time is in progress, on the one hand, the development of established lines of research, on the other hand, the opening of new issues of broad prospects. Among the first it is worth noting the research
on galloping and cables 104, 105, fatigue 106, 107 and the propagation of uncertainties 107, 108. Among the latter it deserves to be highlighted the research conducted during the PhD thesis of Alessio Torrielli and Michela Marrè Brunenghi.
Born around the study of the structural safety under wind loading, the thesis of Alessio Torrielli, conducted under the supervision of Maria Pia Repetto and Giovanni Solari, has led to the formulation of analytical and numerical techniques to simulate long‐term time histories of the mean wind speed (tens of thousands of
years) (Figure 70) 109. Thanks to these procedures it has been addressed, in an innovative way, one of the most hotly debated topics of wind engineering, the distribution of extreme speed 110. At the same time a new project has been undertaken to determine the fatigue damage taking into account the correlation
structure of the mean wind speed process 111. In such a way, completely unexplored horizons for safety assessment of structures have been opened.
32
0
0.5
1
105
105
100
101
102
103
104
105
0
0.5
1
T (h)33 yr 1 yr 6 hr 20 min
a)
b)
c)
d)
W1
W2
S2
S1
T [hr]
2 10 100 1000 1000015
20
25
30
35
40
45
Mean return period [yr]
v [m
/s]
DataFT1 ult.FT1 pen.GEVProcess
Figure 70. (a) Power spectrum of the probable wind, (b) comparison between extreme distributions.
The thesis of Michela Marrè Brunenghi, carried out under the supervision of Luigi Carassale, is opening new perspectives on the representation of random fields using mathematical tools aimed at capturing the most relevant physical aspects of the pressure distributions and synthesizing these by proper modes that may highlight their major issues. Taking cue from Proper Orthogonal Decomposition by (POD), which expresses a field through a linear combination of orthogonal modes weighted by uncorrelated principal components, the thesis has first applied the Independent Component Analysis (ICA) technique, which expresses the field through a linear combination of non‐orthogonal modes weighed by statistically independent principal components, up to develop a novel method, called Dynamic ICA, where the modes are functions of time (Figure 71) and the linear combination involves, in the time domain, convolution integrals, in the frequency
domain, generalized Fourier transformed 112, 113.
Figure 71. First (a) and second (b), D‐ICA mode of the wind pressure on the lateral face of a building.
6. Perspectives
It 's quite obvious that these initiatives will find an obstacle in the limited space available to the Research Group in Villa Cambiaso. The prospect of transferring the Faculty of Engineering on the Erzelli Hill opens up new scenarios. In this context, with great confidence, the Research Group sought and obtained a large space for the transfer of the existing closed‐circuit wind tunnel and the construction of a new large open‐circuit wind tunnel (Figure 72). Relying on an exponential growth in its use, there are plans to create two complementary facilities that could allow the covering of almost unlimited types of tests, and also ensure the possibility of using the two tunnels for parallel basic and applied research.
33
Figure 72. Preliminary plan for the new Laboratory of Wind Engineering in Erzelli.
The hope is strong that the Research Group in Wind Engineering will soon be transformed into a Centre of Excellence institutionalized, taking into account that in recent years no other research center in the world has received so numerous and prestigious international awards as Genoa. In 2007 Luigi Carassale received the Junior Award established by the International Association for Wind Engineering, for leader researchers under the age of 40 years. In 2011 Maria Pia Repetto repeated this success. Giovanni Solari was awarded, respectively in 2006 and 2011, the Jack E. Cermak and the Alan G. Davenport Medals, named after the two founding fathers of wind engineering.
After a review process that lasted over a year, in November 2011, the Research Group in Wind Engineering was selected by the University of Genoa in the limited forum of their own groups of research of greater prestige and quality.
Genoa, September 21, 2012
34
References
1 Solari, G. (1981). DAWROS: A computer program for calculating the dynamic alongwind response of structures, Istituto di Scienza delle Costruzioni, Università di Genova, Serie IV, 1.
2 Solari, G. (1982). Alongwind response estimation: closed form solution. Journal of the Structural Divi‐sion, ASCE, 108, 1, 225‐244.
3 Solari, G. (1983). Analytical estimation of the alongwind response of structures. Journal of Wind Engi‐neering and Industrial Aerodynamics, 14, 467‐477.
4 Lagomarsino, S., Piccardo, G., Solari, G. (1992). Statistical analysis of high return period wind speeds. Journal of Wind Engineering and Industrial Aerodynamics, 41, 485‐496.
5 Ballio, G., Lagomarsino, S., Piccardo, G., Solari, G. (1991). Un primo passo verso la mappa dei venti e‐stremi italiani. Parte 1: Criteri generali e metodologia di analisi, Costruzioni Metalliche, 3.
6 Ballio, G., Lagomarsino, S., Piccardo, G., Solari, G. (1991). Un primo passo verso la mappa dei venti e‐stremi italiani. Parte 2: Risultati, riflessi normativi e implicazioni progettuali, Costruzioni Metalliche, 4.
7 Ballio, G., Lagomarsino, S., Piccardo, G., Solari, G. (1994). La nuova mappa dei venti estremi italiani, Giornale del Genio Civile, 7,8,9.
8 Solari, G. (1988). Equivalent wind spectrum technique: theory and applications. Journal of Structural Engineering, ASCE, 114, 6, 1303‐1323.
9 Solari, G. (1989). Wind response spectrum. Journal of Engineering Mechanics, ASCE, 115, 9, 2057‐2073.
10 Solari, G. (1993). Gust buffeting. I: peak wind velocity and equivalent pressure. Journal of Structural Engineering, ASCE, 119, 2, 365‐382.
11 Solari, G. (1993). Gust buffeting. II: dynamic alongwind response. Journal of Structural Engineering, ASCE, 119, 2, 383‐398.
12 Solari, G., Kareem, A. (1998). On the formulation of ASCE7‐95 gust effect factor. Journal of Wind En‐gineering and Industrial Aerodynamics, 77 & 78, 673 ‐ 684.
13 Solari, G. (1985). Mathematical model to predict 3‐D wind loading on buildings. Journal of Engineer‐ing Mechanics, ASCE, 111, 2, 254‐276.
14 Solari, G. (1986). 3‐D response of buildings to wind action. Journal of Wind Engineering and Industrial Aerodynamics, 21, 379‐393.
15 Lagomarsino, S., Solari, G. (1995). The wind‐induced dynamic behaviour of the South‐Milan Tele‐communication Tower, Studi e Ricerche, Scuola di Specializzazione in Costruzioni in c.a. Fratelli Pesen‐ti, Politecnico di Milano, 16.
16 Bocciolone, M., Gasparetto, M., Lagomarsino, S., Piccardo, G., Ratto, C.F., Solari, G. (1993). Statistical analysis of extreme wind speeds in the Straits of Messina. Journal of Wind Engineering and Industrial Aerodynamics, 48, 359‐377.
17 Ballio, G., Solari, G. (1992). La Torre del Parco di Milano: una costruzione metallica del 1933 alla luce delle conoscenze passate e presenti, Costruzioni Metalliche, 3, 4.
18 Ballio, G., Maberini, F., Solari, G. (1992). A 60 years old, 100 m high steel tower: limit states under wind actions. Journal of Wind Engineering and Industrial Aerodynamics, 43, 2089‐2100.
19 Solari, G., Pagnini, L.C., Piccardo, G. (1997). A numerical algorithm for the aerodynamic identification of structures. Journal of Wind Engineering and Industrial Aerodynamics, 69, 719‐730.
20 Solari, G., Reinhold, T.A., Livesey, F. (1998). Investigation of wind actions and effects on the Leaning Tower of Pisa. Wind and Structures, 1, 1‐23.
21 Piccardo, G. (1993). A methodology for the study of coupled aeroelastic phenomena. Journal of Wind Engineering and Industrial Aerodynamics, 48, 241‐252.
22 Solari, G. (1994). Gust‐excited vibrations, in Wind‐excited vibrations of structures, H. Sockel Editor, Springer Verlag, Wien, New York, 195‐291.
23 Piccardo, G., Solari, G. (1998). Closed form prediction of 3‐D wind‐excited response of slender struc‐tures. Journal of Wind Engineering and Industrial Aerodynamics, 74‐76, 697‐708.
24 Piccardo, G., Solari, G. (2000). 3‐D wind‐excited response of slender structures: Closed form solution. Journal of Structural Engineering, ASCE, 126, 8, 936‐943.
35
25 Solari, G. (1996). Evaluation and role of damping and periods for the calculation of structural re‐sponse under wind loads. Journal of Wind Engineering and Industrial Aerodynamics, 59, 191‐210.
26 Solari, G. (1997). Wind‐excited response of structures with uncertain parameters. Probabilistic Engi‐neering Mechanics, 12, 2, 75‐87.
27 Pagnini, L.C. (1996). Model reliability and propagation of frequency and damping uncertainties in the dynamic alongwind response of structures. Journal of Wind Engineering and Industrial Aerodynamics, 59.
28 Pagnini, L.C., Solari, G. (1998). Serviceability criteria for wind‐induced acceleration and damping un‐certainties. Journal of Wind Engineering and Industrial Aerodynamics, 74‐76, 1067‐1078.
29 Solari, G. (2002). Integrated procedures in wind engineering. Fluid Mechanics Research, 29, 323‐328.
30 Luongo, A., Piccardo, G. (1998). Non‐linear galloping of sagged cables in 1:2 internal resonance, Jour‐nal of Sound and Vibration, 214, 915‐940.
31 Luongo, A., Paolone, A., Piccardo, G. (1998). Postcritical behavior of cables undergoing two simulta‐neous galloping modes. Meccanica, 33, 229‐242.
32 Pagnini, L.C., Solari, G. (2001). Damping measurements of steel poles and tubular structures, Engi‐neering Structures, 23, 1085‐1095.
33 Solari, G., Pagnini, L.C. (1999). Gust buffeting and aeroelastic behaviour of poles and monotubolar towers. Journal of Fluids and Structures, 13, 7‐8, 877‐905.
34 Solari, G., Pagnini, L.C. (1998). Le azioni e gli effetti del vento sui pali e sulle torri monotubolari. Co‐struzioni Metalliche, n. 4.
35 Tamura Y., Matsui M., Pagnini L.C., Ishibashi R., Yoshida A. (2002). Measurement of Wind‐induced re‐sponse of buildings using RTK‐GPS. Journal of Wind Engineering and Industrial Aerodynamics, 90.
36 Solari, G. (1996). Wind speed statistics, in Modelling of the Atmospheric Flow Fields, D.P. Lalas and C.F. Ratto Editors, World Scientific Publishing, Singapore, 637‐657.
37 Solari, G. (1996). Statistical analysis of extreme wind speeds, in Modelling of the Atmospheric Flow Fields, D.P. Lalas and C.F. Ratto Eds, World Scientific Publishing, Singapore, 659‐678.
38 Ratto, C., Siccardi, F., Solari, G. (1995). Il Centro Meteo‐Idrologico della Regione Liguria: Una collabo‐razione fra Regione Liguria e Università di Genova, AER, n. 11.
39 Castino, F., Rusca, L., Solari, G. (2003). Wind climate micro‐zoning: A pilot application to Liguria Re‐gion (North‐Western Italy), Journal of Wind Engineering and Industrial Aerodynamics, 91, 1353‐1375.
40 Solari, G., Ed. (1997). Proceedings of the 2nd European & African Conference on Wind Engineering, Genova, Italy, June 22‐26, 1997, SGEditoriali, Padova, 2000 pp.
41 Ratto, C.F., Solari, G., Eds. (1998). Proceedings of the International Workshop on Wind Energy and Landscape, Genova, Italy, June 26‐27, 1997, Balkema, Rotterdam, 300 pp.
42 Choi, C.K., Solari, G., Kanda, J., Kareem, A., Eds. (2000). Wind and Structures, Techno Press, Seoul.
43 Choi, C.K., Solari, G., Kanda, J., Kareem, A., Eds. (2000). Proceedings of the 1st International Sympo‐sium on Wind and Structures for the 21st Century, Cheju, Korea; Techno Press, Seoul, 500 pp.
44 Choi, C.K., Kareem, A., Matsumoto, M., Solari, G., Eds. (2002). Proceedings of the 2nd International Symposium on Wind and Structures for the 21st Century, Busan, Korea; Techno Press, Seoul, 701 pp.
45 Solari, G., Pagnini, L.C., Piccardo, G., Eds. (2000). L'ingegneria del vento in Italia 2000: Atti del VI Con‐vegno Nazionale di Ingegneria del Vento, Genova; SGEditoriali, Padova, 600 pp.
46 Piccardo, G., Solari, G. (2002). 3‐D gust effect factor for slender vertical structures, Probabilistic Engi‐neering Mechanics, 17, 143‐155.
47 Solari, G., Repetto, M.P. (2002). General tendencies and classification of vertical structures under wind loads, Journal of Wind Engineering and Industrial Aerodynamics, 90, 1299‐1319.
48 Repetto, M.P., Solari, G. (2004). Equivalent static wind actions on vertical structures, Journal of Wind Engineering and Industrial Aerodynamics, 92, 335‐357.
49 Luongo, A., Piccardo, G. (2005). Linear instability mechanisms for coupled translational galloping, Journal of Sound and Vibration, 288, 1027‐1047.
50 Luongo, A., Zulli, D., Piccardo, G. (2007). A linear curved‐beam model for the analysis of galloping in suspended cables, Journal of Mechanics of Materials and Structures, 2, 675‐694.
36
51 Luongo, A., Piccardo, G. (2007). A continuous approach to the aeroelastic stability of suspended ca‐bles in 1:2 internal resonance, Journal of Vibration and Control, 14(1‐2), 135‐157.
52 Luongo, A., Zulli, D., Piccardo, G. (2008). Analytical and Numerical Approaches to Nonlinear Galloping of Internally Resonant Suspended Cables, Journal of Sound and Vibration, 315(3), 375‐393.
53 Luongo, A., Zulli, D., Piccardo, G. (2009). On the Effect of Twist Angle on Nonlinear Galloping of Sus‐pended Cables, Computers & Structures, 87(15‐16), 1003‐1014.
54 Solari, G., Carassale, L. (2000). Modal transformation tools in structural dynamics and wind engineer‐ing. Wind & Structures, 3, 4, 221‐241.
55 Carassale, L. (2005). POD‐based filters for the representation of random loads on structures. Probabil‐istic Engineering Mechanics, 20, 263‐280.
56 Solari, G., Carassale, L., Tubino, F. (2007). Proper Orthogonal Decomposition in wind engineering. Part 1: A state‐of‐the‐art and some prospects, Wind & Structures, 10, 153‐176.
57 Carassale, L., Solari, G., Tubino, F. (2007). Proper Orthogonal Decomposition in wind engineering. Part 2: Theoretical aspects and some applications, Wind & Structures, 10, 177‐208.
58 Carassale, L., Piccardo, G., Solari, G. (2001). Double modal transformation and wind engineering ap‐plications, Journal of Engineering Mechanics, ASCE, 127, 5, 432‐439.
59 Carassale, L., Kareem, A. (2002), A Volterra approach for nonlinear multi‐DOF structures. Structural Dynamics, Proc., EURODYN 2002, 1, 755‐760.
60 Carassale, L., Kareem, A. (2010). Modeling multi‐input nonlinear systems by Volterra approach. Jour‐nal of Engineering Mechanics ASCE, Modeling nonlinear systems by Volterra Series, Journal of Engi‐neering Mechanics ASCE, 136(6), 801‐818.
61 Carassale, L., Piccardo, G. (2003). Wind‐induced nonlinear oscillations of cables by Volterra approach. Proc., 5th Int. Symp. on Cable Dynamics, Santa Margherita, 149‐156.
62 Carassale, L., Piccardo, G. (2010). Nonlinear discrete models for the stochastic analysis of cables in turbulent wind, International Journal of Non‐Linear Mechanics, 45(3), 219‐231.
63 Repetto, M.P., Solari, G. (2001). Dynamic alongwind fatigue of slender structures, Engineering Struc‐tures, 23, 1622‐1633.
64 Repetto, M.P., Solari, G. (2002). Dynamic crosswind fatigue of slender vertical structures, Wind & Structures, 5, 527‐542.
65 Repetto, M.P., Solari, G. (2004). Directional wind‐induced fatigue of slender vertical structures, Jour‐nal of Structural Engineering, ASCE, 130, 7, 1032‐1040.
66 Repetto, M.P. (2005). Cycle counting methods for bi‐modal stationary Gaussian processes. Probabilis‐tic Engineering Mechanics, 20, 229‐238.
67 Repetto, M.P., Solari, G. (2006). Bimodal alongwind fatigue of structures, Journal of Structural Engi‐neering, ASCE, 132, 6, 899‐908.
68 Repetto, M.P., Solari, G. (2007). Wind‐induced fatigue of structures under neutral and non‐neutral atmospheric conditions, Journal of Wind Engineering and Industrial Aerodynamics, 95, 1364‐1383.
69 Repetto, M.P., Solari, G. (2010). Wind‐induced fatigue collapse of real slender structures. Engineering Structures, 32, 3888‐3898.
70 Repetto, M.P., Solari, G. (2008). Simplified procedure for evaluating the alongwind‐induced fatigue of structures. Engineering Structures, 31, 2414‐2425.
71 Repetto, M.P., Solari, G. (2011). Engineering methods for evaluating the alongwind‐induced fatigue of structures. Journal of Engineering Structures, ASCE, 138(9), 1149‐1160.
72 Solari, G., Piccardo, G. (2001). Probabilistic 3‐D turbulence modeling for gust buffeting of structures. Probabilistic Engineering Mechanics, 16, 1, 73‐86.
73 Solari, G., Tubino, F. (2002). A new turbulence model based on principal components. Probabilistic Engineering Mechanics, 17, 327‐335.
74 Carassale, L., Solari, G. (2002). Wind modes for structural dynamics: a continuous approach. Probabil‐istic Engineering Mechanics, 17, 157‐166.
75 Tubino, F., Solari, G. (2005). Double POD for representing and simulating turbulence fields, Journal of Engineering Mechanics, ASCE, 131, 12, 1302‐1312.
37
76 Tubino, F. (2005). Relationships among aerodynamic admittance functions, flutter derivatives and static coefficients for long‐span bridges. Journal of Wind Engineering and Industrial Aerodynamics, 93, 929‐950.
77 Tubino, F., Solari, G. (2007). Double Modal Transformation and effective turbulence for the gust buf‐feting of long span bridges, Engineering Structures, 29, 1698‐1707.
78 Torrielli, A., Tubino, F., Solari, G. (2010). Effective wind actions on ideal and real structures. Journal of Wind Engineering and Industrial Aerodynamics, 98, 417‐428.
79 Tubino, F., Carassale, L., Solari, G. (2003). Seismic response of multi‐supported structures by proper orthogonal decomposition. Earthquake Engineering and Structural Dynamics, 32, 1639‐1654.
80 Carassale, L., Freda, A., Piccardo, G. (2005). Aeroelastic forces on yawed circular cylinders: Quasi‐steady modeling and aerodynamic instability. Wind & Structures, 8, 373‐388.
81 Carassale, L. (2009). Flow‐induced actions on cylinders in statistically‐symmetric cross flow, Probabil‐istic Engineering Mechanics, 24(3), 288‐299.
82 Burlando, M., Carassale, L., Georgieva, E., Ratto, C.F., Solari, G. (2007). A simple and efficient proce‐dure for the numerical simulation of wind fields in complex terrain, Boundary Layer Meteorology, 125, 417‐439.
83 Burlando, M., Carassale, L., F., Ratto, C.F., Solari, G. , Tubino (2010). Numerical simulation of turbu‐lent wind fields at airports in complex terrains. Journal of Wind Engineering and Industrial Aerody‐namics, sottoposto per la pubblicazione.
84 Carassale, L., Solari, G. (2006). Monte Carlo simulation of wind velocity fields on complex structures, Journal of Wind Engineering and Industrial Aerodynamics, 94, 323‐339.
85 Brancaleoni, F., Diana, G., Faccioli, E., Fiammenghi, G., Firth, I.P.T., Gimsing, N.J., Jamiolkowski, M., Sluszka, P., Solari, G., Valenise, G., Vullo, E. (2009). Messina Strait Bridge – The challenge and the dream, Balkema.
86 Burlando, M., Freda, A., Ratto, C.F., Solari, G. (2010). A pilot study of the wind speed along the Rome‐Naples HS/HC railway line. Part 1 – Numerical modelling and wind simulations. Journal of Wind Engi‐neering and Industrial Aerodynamics, 98, 392‐403.
87 Freda, A., Solari, G. (2010). A pilot study of the wind speed along the Rome‐Naples HS/HC railway line. Part 2 – Probabilistic analyses and methodology assessment. Journal of Wind Engineering and Industrial Aerodynamics, 98, 404‐416.
88 Freda, A., Carassale, L., Solari, G. (2009). A conditional model for the short‐term probabilistic assess‐ment of severe wind phenomena, C.D. Proc., 5th European‐African Conference on Wind Engineering, Firenze.
89 Lungu, D., Solari, G., Bartoli, G., Righi, M., Vacareanu, R., Villa, A. (2002). Reliability under wind loads of the Brancusi Endless Column, Romania, Fluid Mechanics Research, 29, 329‐335.
90 Piccardo, G., Tubino, F. (2008). Parametric Resonance of Flexible Footbridges under Crowd‐Induced Lateral Excitation, Journal of Sound and Vibration, 311(1‐2), 353‐371.
91 Piccardo, G., Tubino, F. (2009). Simplified Procedures for Vibration Serviceability Analysis of Foot‐bridges Subjected to Realistic Walking Loads”, Computers & Structures, 87(13‐14), 890‐903.
92 Solari, G. (2009). Forma e aerodinamica nell’evoluzione strutturale e architettonica dei grattacieli. Parte I: L’esperienza del passato. Costruzioni Metalliche, n. 4, 51‐62.
93 Solari, G. (2009). Forma e aerodinamica nell’evoluzione strutturale e architettonica dei grattacieli. Parte II: Tendenze attuali e prospettive future. Costruzioni Metalliche, n. 5, 75‐87.
94 Tamura, Y., Kareem, A., Solari, G., Kwok, K.C.S., Holmes, J.D., Melbourne, W.H. (2005). Aspects of the dynamic wind‐induced response of structures and codification, Wind & Structures, 8, 4, 251‐268.
95 Solari, G. (2007). The International Association for Wind Engineering (IAWE): Progress and prospect, Journal of Wind Engineering and Industrial Aerodynamics, 95, 813‐842.
96 Solari, G., Cheung, J., Isyumov, N., Kareem, A., Stathopoulos, T., Surry, D., Tamura, Y. (2008). The Davenport Medal: A tribute from the International Association for Wind Engineering to Alan Garnett Davenport, Journal of Wind Engineering and Industrial Aerodynamics, 96, 459‐470.
97 Carassale, L., Percivale, F. (2006). Frequency‐domain output‐only identification of linear structures subject to stationary excitation, Proc., 5th Int. Conf. on Computational Stochastic Mechanics, Rodi.
38
98 Carassale, L., Freda, A., Ratto, C.F., Solari, G., Talamelli, A. (2008). La nuova galleria del vento presso la Facoltà di Ingegneria dell’Università degli Studi di Genova, Atti, IN‐VENTO‐2008, Cefalù.
99 Solari, G., Repetto, M.P., De Gaetano, P., Parodi, M., Pizzo, M., Tizzi, M. (2012). The wind forecast for safety management of port areas, Journal of Wind Engineering and Industrial Aerodynamics, 104–106, 266–277.
100 Solari G., Repetto M.P., Burlando M. (2012). Vento e Porti – La previsione del vento per la gestione e la sicurezza delle aree protuali / Vent et Ports – La prévision du vent pour la gestion et la sécurité des zones portuaires, A. P. Genova Ed., ISBN 978‐88‐901246‐4‐8.
101 Carassale L., Freda A., Repetto M.P., Solari G. (2011). The wind effect on the new Erzelli Technologic District, CD Proc. 13th International Conference on Wind Engineering (ICWE13), Amstrerdam, The Netherlands, July 10‐15, 2011.
102 Carassale, L., Freda, A., Marrè Brunenghi, M., Piccardo, G., Solari, G. (2012). Experimental investiga‐tion on the aerodynamic behavior of square cylinders with rounded corners, Proceedings, 7th Inter‐national Colloquium on Bluff Body Aerodynamics and Applications ‐ BBAA VII, Shanghai, Cina.
103 Carassale, L., Freda, A., Marrè Brunenghi, M., Piccardo, G., Solari, G. (2012). Effects of terrain prox‐imity on the aeroelastic response of a bridge deck, Proceedings, 7th International Colloquium on Bluff Body Aerodynamics and Applications ‐ BBAA VII, Shanghai, Cina.
104 Carassale, L., Piccardo, G. (2010). Non‐linear discrete models for the stochastic analysis of cables in turbulent wind, International Journal on Non‐Linear Mechanics, 45(3), 219‐231.
105 Piccardo, G., Carassale, L., Freda, A. (2011). Critical conditions of galloping for inclined square cylin‐ders, Journal of Wind Engineering and Industrial Aerodynamics, 99 (6‐7), 748‐756.
106 Repetto M.P. (2011). Neutral and non‐neutral atmosphere: probabilistic characterization and wind‐induced response of structures, Journal of Wind Engineering and Industrial Aerodynamics, 99, 969‐978.
107 Pagnini, L., Repetto, M.P. (2012). The role of parameter uncertainties in the alongwind‐induced fa‐tigue damage prediction, Journal of Wind Engineering and Industrial Aerodynamics, 104–106, 227–238.
108 Pagnini, L.C. (2010). Reliability analysis of wind excited structures, Journal of Wind Engineering and Industrial Aerodynamics, 98, 1‐9.
109 Torrielli, A., Repetto, M.P., Solari, G. (2011). Simulation of long‐period samples of the mean wind ve‐locity, Journal of Wind Engineering and Industrial Aerodynamics, 99, 1139‐1150.
110 Torrielli, A., Repetto, M.P., Solari, G. (2011). Analysis of a large‐size database of extreme wind speeds, Journal of Wind Engineering and Industrial Aerodynamics, tentatively accepted.
111 Repetto, M.P., Torrielli, A. (2011). Comparison between analytical and simulation‐based wind‐induced fatigue analyses, CD Proc., 13th International Conference on Wind Engineering, Amsterdam.
112 Carassale, L., Marrè Brunenghi, M. (2011). Statistical analysis of wind‐induced pressure fields: a methodological perspective, Journal of Wind Engineering and Industrial Aerodynamics, 99 (6‐7), 700‐710.
113 Carassale, L. (2012). Analysis of aerodynamics pressure measurements by dynamic coherent struc‐tures. Probabilistic Engineering Mechanics, 28, 66‐74.
![Module Handbook Master “Wind Engineering” · help Guide. Springer, 2007 Module Handbook - Master „Wind Engineering“ 6 Module number [2]: Global Wind industry and environmental](https://img.pdfslide.net/doc/110x75/5eaa6805c6c64676ff4bba1d/module-handbook-master-aoewind-engineeringa-help-guide-springer-2007-module.jpg)
