* only the first 6 pages of this project is presented here. If you are interested to study the rest of this document please contact me via saeid.ghaffari@studenti.polito.it. With respect to the importance of the T-joint in a vehicle body strength, this project aims to study the joint torsional and bending stiffness in the two main directions. Furthermore, the influence of the number of spot welds on the stiffness of the joint will be analysed benefiting from Altair Hyperworks (Hypermesh FEA software).

1. Department of
Mechanical and
Aerospace Engineering
Saeid Ghaffari
Professor: Alessandro Scattina
Automotive Engineering - A.Y. 2017-2018
A Study on how Spot Welds
Affect the Stiffness of a Car Body
T-joint

2. I N T R O D U C T I O N
With respect to the importance of the T-joint in a vehicle body strength, we study the following aspects
of a typical T-joint of a vehicle:
o The evaluation of the joint torsional stiffness
o The evaluation of bending stiffness in the two main directions
o The evaluation of the influence of the number of spot welds on the stiffness of the joint
A STUDY ON HOW SPOT WELDS AFFECT THE STIFFNESS OF A CAR BODY T-JOINT 2Automotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering

3. 3
Department of Mechanical
and Aerospace Engineering
I N T R O D U C T I O N
o Geometry
Half of the full model is given by a .igs file format. The dimensions of the
given model are shown in the figure.
The full model will be modelled using “reflect” submenu.
40mm
54 mm
192 mm
338.6mm
92mm
Thickness of the metal sheet: 1mm
A STUDY ON HOW SPOT WELDS AFFECT THE STIFFNESS OF A CAR BODY T-JOINTAutomotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering

4. 4
Department of Mechanical
and Aerospace Engineering
I N T R O D U C T I O N
o Material
The material properties of the T-joint is given in the following table.
S T E E L
Module of Elasticity (MPa) Poisson Ratio Density (Gkg/l)
210000 0.3 7.8e-9
A STUDY ON HOW SPOT WELDS AFFECT THE STIFFNESS OF A CAR BODY T-JOINTAutomotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering

5. 5
Department of Mechanical
and Aerospace Engineering
Processing
Results
Solution/
Analysis
Creating
Loads and
Boundary
Conditions
Assigning
Material
and
Physical
Property
Meshing
P R O C E D U R E
The workflow for Linear Static Analysis in every FEA software is presented in the chart.
A STUDY ON HOW SPOT WELDS AFFECT THE STIFFNESS OF A CAR BODY T-JOINTAutomotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering

6. 6
Department of Mechanical
and Aerospace Engineering
P R O C E D U R E
o Meshing
After importing the model, we mesh the half model using mixed (trias+quads) shell elements using
2D > “Automesh” menu. The size of the elements is selected as 5 mm.
A STUDY ON HOW SPOT WELDS AFFECT THE STIFFNESS OF A CAR BODY T-JOINTAutomotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering