You are to utilise ANSYS Workbench to conduct structural finite element analyses on the provided base geometries

Assignment Overview

Background

Your group has been tasked with the design of a shaft rocker and a lower suspension wishbone for a vehicle.

The primary function of the shaft rocker is to facilitate the actuation of two springs (nominally the roll and heave springs) due to the applied loading from a pushrod attached to the wheel assembly of the vehicle. The rocker is subjected to torsional and bending stress due to the loading from the pushrod, the reaction forces from the springs and the kinematics of the system.

The rocker mounts on bearings on either end of the axial length of the shaft, between which the attachment points for the pushrod and springs are located. The design needs to be capable of meeting mass, strength, stiffness, and fatigue life performance targets.

The lower wishbone features two “inboard” connection points attaching to the vehicle’s chassis and a single “outboard” point which connects to the wheel assembly. The wishbone serves to transmit some of the loading from the tyre’s contact with the road surface to the chassis.

The inboard points are located on the chassis using spherical bearings, with the load applied to the outboard point acting in plane with the wishbone (the plane being formed by the inboard and outboard points). The final design must satisfy mass, strength, stiffness, and buckling load performance targets.

Your group will be provided with:

• Initial geometry of the two components
• A definition of minimum design features and restrictions
• Details of the loading cases to be withstood
• Material specifications

Your group is to design a shaft rocker and lower wishbone that satisfy the Design Targets for all Load Cases.

Task

You are to utilise ANSYS Workbench to conduct structural finite element analyses on the provided base geometries from Canvas for the shaft rocker and wishbone using the load cases found in Table A1.

Both components are to be manufactured using the default Aluminium Alloy found in ANSYS Workbench.

For the wishbone, your team must conduct an eigenvalue buckling analysis to determine the buckling safety factor.
For the rocker, your team must conduct an appropriate fatigue analysis using the RockerHistory.dat as the loading history (with a design life of 1000 blocks).

In the initial analyses, your group should ensure appropriate setup of your finite element model, including:

• Element and meshing strategies
• Boundary conditions
• Appropriate outputs

Utilising the results of these initial analyses, your group should work to modify the geometry of the components using SpaceClaim to satisfy the performance requirements found in Table A2.
Modifications to the shaft rocker and wishbone geometries are subject to Table A3.

The final geometry of the pedals must satisfy the requirements laid out in Table A2.

Assessment Summary: MIET1084 – Finite Element Analysis

Assessment Requirements

The assessment required students to design and analyse two key automotive suspension components  the shaft rocker and the lower suspension wishbone — using ANSYS Workbench. The purpose was to evaluate and improve their performance in terms of mass, strength, stiffness, fatigue life, and buckling resistance.

Key assessment tasks included:

1. Conducting finite element analyses (FEA) on base geometries for both components using the provided load cases (Table A1).
2. Using Aluminium Alloy (default ANSYS material) for both components.
3. Performing a fatigue analysis on the shaft rocker using the RockerHistory.dat file for a design life of 1000 loading blocks.
4. Conducting an eigenvalue buckling analysis on the lower wishbone to determine its buckling safety factor.
5. Ensuring proper model setup including:
   • Element type and meshing strategy
   • Boundary conditions and load applications
   • Accurate and relevant output parameters
6. Modifying the component geometries using ANSYS SpaceClaim to meet the specified performance targets in Table A2 while adhering to design restrictions in Table A3.
7. Validating that the final geometry satisfies all design requirements for stiffness, strength, fatigue, and mass efficiency.