Author: Jingsi Wu, Cornell University
Problem Specification
1. Pre-Analysis & Start-Up
2. Geometry
3. Mesh
4. Physics Setup
5. Numerical Solution
6. Numerical Results
7. Verification & Validation
Exercises
Comments
In order to do this exercise, you must have Ansys Composite Prepost installed.
All video tutorials contain audio instructions
Modal Analysis of a Composite Monocoque
Created using ANSYS 14.0
Problem Specification
One of the important measure in race car design is torsional stiffness. To obtain that specification, a twist test must be performed on the chassis. Here is a simplified version of race car chassis with a composite monocoque and two front suspension links. To simulate a twist test, the back of the monocoque will be fixed while coupling will be applied to the end of the two front suspensions. The .igs file for the geometry can be downloaded here: monocoque.IGS.
The analytical calculation of the problem are explained in this PDF document. These passages are taken from the isotropic analysis section of "Design, Analysis and Testing of a Formula SAE Carbon Fiber Monocoque Chassis" by Jingsi Wu, Owusu A. Agyeman Badu, and Yongcheng Tai.
Geometry Specification
One of the beauty of composite material is to customize the ply lay-ups to achieve optimum properties according to the needs. It is often the case where different ply lay-ups are used at different monocoque regions for their specific needs. This exercise has 4 different regions as shown in the diagram below:
Details of the composite layup will be explain during the exercise.
Calculate the Torsional Stiffness
Ansys gives tangential displacement values for torsional displacement. Here are the equations to calculate torsional stiffness.