Undergrad Thesis on 'DESIGN AND FABRICATION OF A MODEL TOWER AND STRESS ANALYSIS OF THE MODEL TOWER USING CAD SOFTWARE

8/9/2019 Undergrad Thesis on 'DESIGN AND FABRICATION OF A MODEL TOWER AND STRESS ANALYSIS OF THE MODEL TOWER USING CAD SOFTWARE'

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Prof. Dr. Maksud Helali

Department of MechanicalEngineering

Bangladesh University of

Engineering And Technology

Dhaka

Lal falah-al MD. Jumma #200618023Mohammad Johirul Islam #200618034

Farhana Yasmin Poly #200618042


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The objectives of the thesis were:

To learn how to operate CAD software

To design a self supported lattice tower in CAD in2-D and 3-D

To simulate the self supported lattice tower inCAD in 2-D and 3-D

To solve the same design theoretically (only for 2-D)


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To build a self supported lattice tower as a model

To take experimental datas from the tower

To make the joints similar

Avoided welding joints, discontinuity of diagonalmembers

Make the model isotropic and experiment on it.

To compare the result from CAD, theory and

experimental model


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Design the tower through CAD

software.

Use Finite Element Method as thebase of the CAD software.

To determining deflection on the

towerExperimental method

Intermediate method


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There are three different types of tower

Lattice tower

Monopole tower

Guyed tower


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Because monopole tower is limited to200ft height

Guyed tower requires more space But lattice tower is

Self supported

High flexibility Can raise its height limitlessly.


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There are five stress

Tension

Compression Bending

Shear

Torsion


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Wind load

Dead load


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Loading stand


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Hole Number Angle,

De

flection,

(mm)

Load (Kg)

2+2 3+3 4+4 5+5 7.5+7.5 9.5+9.

5

H-1 -4.784 0.26 0.33 0.45 0.75 1.03 1.49

H-2 -0.685 0.66 0.81 0.92 1.07 1.67 2.24

H-3 3.42 0.76 1.31 1.84 2.37 2.87 3.62

H-4 7.49 1.07 1.22 1.47 1.67 2.34 3.38

H-5 11.489 1.125 1.35 1.725 2.16 2.67 3.07

H-6 15.376 0.77 1.01 1.12 1.32 1.67 2.12

H-7 19.123 0.58 0.71 0.87 0.98 1.33 1.95

H-8 22.707 0.46 0.73 0.95 1.17 1.52 1.86

H-9 26.114 0.67 0.82 1.32 1.49 1.84 2.21

H-10 29.333 0.97 1.51 1.82 2.46 2.78 3.12

H-11 32.36 1.07 1.75 2.18 2.51 3.27 3.61


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For angle -4.784 For angle +15.3756


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Diagonal members

in panel can carry

tension, no

compression acts.

Full panel shear iscarried by

diagonal member

carrying tension.


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FROM ODE &OCE

ON/CF=OG/DE

FROM OCN&DCK

ON/CN=DK/CK

MCN & ECJ

MN/CN=EJ/CJ

F=mg

Mo = 0,

F * h H (h+MG)=0

Panel 1


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Panel 2

Panel 3


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For angle -4.784 For angle +15.3756


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Defining element type. 3D spar8 of link type is selected.

Defining real constant. Cross section area = 0.00897 m.

Defining material properties.

Modulus of elasticity (EX) for Mild steel =210 GPa.

Poisson's ratio (PRXY) for Mild Steel = 0.303

Modeling using nodes.


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(Node number: X, Y, Z)

1: (0, 0, 0) 2: (0, 0.6096, 0) 3: (0.6096, 0.6096, 0) 4: (0.6096, 0, 0)

5: (0.026, 0.026, 0.52)

6: (0.026, 0.5848, 0.52) 7: (0.5848, 0.5848, 0.52)

8: (0.5848, 0.026, 0.52)

9: (0.0521, 0.0521, 1.04) 10: (0.0521, 0.56, 1.04)

11: (0.56, 0.56, 1.04) 12: (0.56, 0.0521, 1.04) 13: (0.0781, 0.0781, 1.56)

14: (0.0781, 0.5353, 1.56)

15: (0.5353, 0.5353, 1.56)

16: (0.5353 ,0.0781, 1.56)


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Applying loads on node 15 and 16.

Loads at different angles are given in Fx

and Fz components. Simulation is done.


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Deformed shape isobtained from plotresult.

Nodal solution isobtained from contourplot.


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Nodal solution :


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PRINT U NODAL SOLUTION PER NODE

***** POST1 NODAL DEGREE OF FREEDOM LISTING *****

LOAD STEP= 1 SUBSTEP= 1 TIME= 1.0000 LOAD CASE= 0

THE FOLLOWING DEGREE OF FREEDOM RESULTS ARE IN THE GLOBAL COORDINATE

SYSTEM

NODE UX UY UZ USUM 1 0.0000 0.0000 0.0000 0.0000 2 0.0000 0.0000 0.0000 0.0000 3 0.0000 0.0000 0.0000 0.0000

4 0.0000 0.0000 0.0000 0.0000 5 0.19278E-03 0.28728E-04 0.12656E-03 0.23239E-03 6 0.19269E-03-0.28291E-04 0.12657E-03 0.23227E-03 7 0.19203E-03 0.27047E-04-0.12258E-03 0.22942E-03 8 0.19214E-03-0.27551E-04-0.12262E-03 0.22959E-03 9 0.59962E-03 0.12234E-04 0.19946E-03 0.63205E-03 10 0.59927E-03-0.11470E-04 0.19943E-03 0.63168E-03 11 0.59538E-03 0.11028E-04-0.19139E-03 0.62548E-03 12 0.59574E-03-0.12014E-04-0.19151E-03 0.62588E-03 13 0.11158E-02 0.31120E-05 0.20256E-03 0.11340E-02 14 0.11151E-02-0.21094E-05 0.20252E-03 0.11333E-02 15 0.11446E-02 0.23321E-05-0.19614E-03 0.11613E-02 16 0.11453E-02-0.37853E-05-0.19626E-03 0.11620E-02

MAXIMUM ABSOLUTE VALUES

NODE 16 5 13 16 VALUE 0.11453E-02 0.28728E-04 0.20256E-03 0.11620E-02


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Angle()

Deflection, (mm)

CAD

Result Theoretical Solution Experimental Result

-4.784 1.162 0.76962 0.45

-0.685 1.182 0.5840 0.92

3.421 1.197 0.750 1.07

7.49 1.205 0.7348 1.01

11.489 1.208 0.7162 1.07

15.3756 1.205 0.6949 1.725

19.123 1.197 0.67056 1.12

22.707 1.184 0.6461 0.87

26.114 1.168 0.623316 0.95

29.333 1.149 0.584835 1.32

32.36 1.128 0.5654 1.82


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for angle -4.784 for angle 7.49


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for angle 22.707 for angle 32.36


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Study for both linear & non linear deflection. Join the additional metal plates at the cutting

edges of members to improve the strength ofthem.

Study of some other important parameters such asfriction load, fatigue load, deflection type &elasticity of wire & their effect on error happening.

Use of deflection sensors instead of dial indicator.

Use different types of load at different points anddifferent angle. Use of other simulation CAD software.


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To measure the load sustainability of atower.

To obtain the possibility maximumdeflection of a tower.

For a definite place where the tower tobe built, what should be the properties ofthe tower members.

To know the maximum height of thetower.


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Undergrad Thesis on 'DESIGN AND FABRICATION OF A MODEL TOWER AND STRESS ANALYSIS OF THE MODEL TOWER USING CAD SOFTWARE