Mechanics of Materials Analysis Strenght to weight ratio BEAM

1. COURSE PROJECT
MECHANICS OF MATERIALS
BY
DINESHY ,
NAVAHARSHA,
AJAYRAJ BALLA

2. AIM : MAXIMUM STIFFNESS TO WEIGHT RATIO AND
ANALYSIS OF MODEL
CONTENTS
1.TOPOLOGY
2.SOLIDWORKS MODEL
3.ACTUAL MODEL
4.EXPERIMENT RESULTS
5.ANALYSIS
6.COMPARISION

3. INTRODUCTION
(+) POISSION RATIO : LATERAL AND AXIAL STAINS HAVE DIFFERENT SIGNS
(-) POISSION RATIO : BOTH WILL HAVE SAME SIGN
Auxetic structures will have NEGATIVE POISSION RATIO
Chiral structures are one of Auxetic structures
DIMENSIONS OF MODEL 160*19*20 (L*B*H)
LIGAMENT
NODE

4. SOLIDWORKS MODEL
THICKNESS 1 mm
NODE OUTER RADIUS 2mm
INNER RADIUS 1mm

5. ACTUAL MODEL
•
PLA MATERIAL IS USED FOR MAKING
WEIGHT OF BEAM 38 grams

6. MAXIMUM LOAD :700N
MAXIMUM DEFLECTION :4.59mm
F/DELTA = 0.1766
EXPERIMENTAL DATA

7. ANALYSIS

8. CALCULATIONS
MOM STIFFNESS COEFFICIENT k(F/DELTA) = 700N/(3.15*0.001)= 222.222 kN/m
STIFFNESS TO WEIGHT RATIO(k/w) = 222.222/(38*0.001) = 5847.94 kN/Kgm
•EXPERIMENTAL (FROM SLOPE OF GRAPH) : 176.600 kN/m
•EXPERIMENTAL STIFFNESS TO WEIGHT : 4647 kN/kg.m

9. `
MOM
ANALYSIS EXPERIMENTAL
DATA
SOLIDWORKS
SIMULATION
DEFLECTION 3.15 4.59 3.86
K 222.222 KN/m 176.600 KN/m 181.3KN/m
K/W 5847.94 KN/Kg.m 4647 KN/Kg.m 4771.05 KN/Kg.m
ERROR FOR
DEFLECTION
WITH
EXPERIMENTAL
DATA
28.9% 15.9%
COMPARISON

10. WHY ERROR?
•
CALCULATING INERTIA WE HAVE TAKEN 5mm INTERVAL SPACING WHICH BECAME
LARGE.
SMALLER INTERVALS CAN REDUCE ERROR PERCENT
MOM ANALYSIS ERROR DUE TO :
SOLIDWORKS SIMULATION ERROR DUE TO:
1.COARSE MESHING IS TAKEN FOR MODEL
2.ACTUAL YOUNGS MODULUS OF FABRICATED MODEL IS DIFFERENT FROM THE
ABS MATERIAL YOUNGS MODULUS

11. THANK YOU
•