In this project we assess the torsional stiffness of a simplified ladder frame chassis in 3 different configurations regarding the connections between the cross members and longitudinal beams as well as the geometry of cross beams; simple cross beams, cross beams with cutted cross section and slotted cross beams are considered here. In order to obtain this goal a simplified model of the frame is built in Altair Hyperworks CAE software. *only the first six pages of this project is presented here. If you are interested to study the rest of this work, please contact me via saeid.ghaffari@studenti.polito.it.

1. 1
Assessing The Torsional Stiffness of a
simplified ladder frame chassis
Prof. Andrea Tonoli
Saeid Ghaffari
Dhruvit Kapuria
Kshitij Sharma
Automotive Engineering - A.Y. 2017-2018
Department of
Mechanical and
Aerospace Engineering

2. Automotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering
• Defining the project
• Pre-processing
Modelling in Hypermesh FE Software
Defining and assigning the Material and Properties
Meshing
Applying boundary conditions
Defining the load steps
• Processing
• Post-processing and results
Outline
2Assessing The Stiffness of a simplified ladder frame chassis

3. Automotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering
DEFINING THE PROJECT
• Aims and how
• Geometry
3Assessing The Stiffness of a simplified ladder frame chassis

4. Automotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering
Defining the project
• Aims
In this project we assess the Torsional stiffness of a ladder frame in 3 different configurations regarding the
connections between the cross members and longitudinal beams as well as the type of the cross section.
• How
In order to obtain this goal, firstly, we model the frame in Hyperworks 2017- Student Edition (as it is very
easy to build this simple frame in the Hypermesh environment and so using CAD software in this case, in
comparison, would be a time-consuming process).
Benefiting from OptiStruct User Interface will provide us an opportunity to analyse structural analysis solver
for Linear and Non-linear problems (as in this case we will do a linear analysis).
In the end we will find the displacement in the position of applying load to evaluate the Torsional Stiffness of
the frame.
4Assessing The Stiffness of a simplified ladder frame chassis

5. Automotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering
Defining the project
• Geometry
We will consider three different cases firstly
regarding the method of connecting the cross
members to the longitudinal beams (case 1 and 2)
and secondly with a slotted cross section of the
cross members in the third case (slotted case).
The overall geometry in all the three cases is the
same. The cases are described in the following
slides.
†Dimensions are in millimetres
150 100
120
1600
2000150
Thickness = 1.5 mm
5Assessing The Stiffness of a simplified ladder frame chassis

6. Automotive Engineering - A.Y. 2017-2018
Department of Mechanical
and Aerospace Engineering
Defining the project
• Geometry
Case 1 (Cutted Case):
In this case, the cross members will not go
through the width of the longitudinal beams,
rather their ends are welded to the inside holes
on the longitudinal beams.
In this particular case we will consider two sub-
cases to see the effects of the application points
of Boundary Conditions on the final results of the
assessment, which will be described in
proceeding slides.
6Assessing The Stiffness of a simplified ladder frame chassis