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StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Structural Dynamics& Earthquake Engineering
Lecture #1: Introduction
Dr Alessandro Palmeri
Civil and Building Engineering @ Loughborough University
Tuesday, 2nd February 2016
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Why bother about Structural Dynamics?
http://www.youtube.com/watch?v=uzdQer1gvsU
http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)
The 1940 TacomaNarrows Bridge
It was a steel suspension bridgein the US state of Washington.Construction began in 1938, withthe opening on 1st July 1940From the time the deck was built,it began to move vertically inwindy conditions (constructionworkers nicknamed the bridgeGalloping Gertie).The motion was observed evenwhen the bridge opened to thepublic.Several measures to stop themotion were ineffective, and thebridge’s main span finallycollapsed under 64 km/h windconditions the morning of 7thNovember 1940.
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Why bother about Structural Dynamics?
http://www.youtube.com/watch?v=eAXVa__XWZ8
http://en.wikipedia.org/wiki/Millennium_Bridge,_London
The Millennium Bridge
It is an iconic steel suspensionbridge for pedestrians crossingthe River Thames in London.Construction began in 1998, withthe opening on 10th June 2000.Londoners nicknamed the bridgethe Wobbly Bridge afterparticipants in a charity walk toopen the bridge felt anunexpected and uncomfortableswaying motion.The bridge was then closed foralmost two years whilemodifications were made toeliminate the wobble entirely.It was reopened in 2002.
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Why bother about Structural Dynamics?
http://dx.doi.org/10.1063/1.2963929
http://www.enea.it/en/en/research-development/new-technologies/materials-technologies
Shaking Table Tests
The video shows the last,destructive shaking table testconducted in 2007 on a 1:2scale model of a masonrybuilding resembling a specialtype (the so-called Tipo MistoMessinese), which is proper tothe reconstruction of the city ofMessina after the 1783 Calabriaearthquake.The model, incorporating a noveltimber-concrete composite slab,has been tested on the mainshaking table available at theENEA Research CentreCasaccia in Rome, both beforeand after thereinforcement with FRP materials.
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Why bother about Structural Dynamics?
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Aim of the Module
This module is aimed at:developing knowledge and understanding ofvibrational problems in structural engineeringand to provide the basic analytical and numerical toolsto assess the dynamic response of structureswith special emphasis on theseismic analysis and design to Eurocode 8
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Intended Learning Outcomes of the Module
On completion of the module you should be able to:Discuss the equations ruling the free and forcedvibration of single-degree-of-freedom (SDoF) oscillators... and multi-degree-of-freedom (MDoF) structuresIllustrate the role of damping and ductility in SDoF andMDoF systemsExploit the concepts of mode of vibration andRayleigh’s quotientCalculate the dynamic response of SDoF and MDoFsystems...
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Intended Learning Outcomes of the Module
... And also to:Interpret provisions of Eurocode 8Evaluate the seismic performance of frame structuresusing linear modelsCompare the behaviour of structures under static anddynamic loads.Critically assess advantages and disadvantages ofdifferent options for the analysis and design ofengineering systems under dynamic loads
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Module Description: Part 1
Dynamics of single-degree-of-freedom (SDoF) systems
Equations of motion for SDoF oscillatorsModelling and evaluation of damping in SDoFoscillatorsDynamic response of SDoF oscillators in both time andfrequency domains
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Module Description: Part 2
Dynamics of multi-degree-of-freedom (MDoF) systems
Equations of motion for MDoF structuresModal analysis and mode superposition methodClassically and non-classically damped MDoFstructuresDynamic response of MDoF structures in both time andfrequency domains
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Module Description: Part 3
Earthquake engineering
Engineering seismology (basics) and seismic action onstructuresElastic response spectrum and ductility-dependentdesign spectraLateral force methodResponse spectrum methodDesign options to improve the seismic performance ofexisting and new buildingsA look into the (near) future: performance-basedearthquake engineering (PBEE)
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Assessment of Module
2-hour examination (75% of the module)Section A (50% of the exam marks) on Parts 1 and 2
Solving 2 out of 3 questions (each one weighting 25%)Section B (50% of the exam marks) on Part 3
Solving 1 out of 2 questions (including somediscursive reasonings, NEW with respect to previousyears)
Coursework comprising an group written assignmentbased on Part 1 (25% of the module)
Issued in Week 4 (Tuesday 23rd February 2016)Handed in Week 9 (Monday 25th April 2016)Returned in Week 12
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Schedule of the Module
Lecture #1 Lecture #2 Tutorial
Week 1 Introduction Equation of motion for SDoFoscillators
—
Week 2 Fourier analysis for structuraldynamics applications
Frequency response functionfor SDoF oscillators
Part 1
Week 3 State-space formulation forSDoF oscillators
Energy dissipation devices forvibration control
Part 1
Week 4 ? Equations of motion forundamped MDoF structures
Modal analysis Part 1
Week 5 Classically and non-classicallydamped MDoF structures
Newmark-β method Part 2
Week 6 State-space formulation forMDoF structures
4th-order Runge-Kutta method Part 2
Week 7 Basics of engineeringseismology
Strong motion characteristics Part 2
Easter break
Week 8 † Elastic response spectrum Ductility µ, behaviour factor qand design spectra
Part 3
Week 9 Lateral force method Part 3Week 10 Response spectrum method Part 3Week 11 Performance-based earthquake engineering Part 3Week 12 ‡ Revision —
? Coursework brief is issued in Week 4† Group report is handed in Week 9 (after Easter) – On Monday 25th April 2016‡ Feedback is given in Week 12 (before the Exams)
StructuralDynamics
& EarthquakeEngineering
Dr AlessandroPalmeri
Motivations forthis module
Introduction tothe module
Equations ofmotion forSDoFoscillators
Questions?