Car Jack Analysis

Figure 1 shows a jack designed to lift small unit body cars of up to mass 514 kg. The car is raised and lowered by turning the 150mm handle which is attached to the threaded bar of diameter 10mm.

Figure 1: Car Jack Design (Souce: Merian & Kraige)

All parts are made form Alloy Steel with a Young’s module of 210GN/m2, Poisson’s ratio of 0.28 and a yield strength of 620.24 MN/m2.

For the configuration shown determine:

1. From a 1D finite element analysis the forces acting on the lower leg which is in contact with the ground.
2. From a 2D finite element analysis, the factor of safety against yield.

The upper and lower leg have a nominal cross-section of 50mm width and a thickness of 6mm.

The analysis must be carried out using Ansys Mechanical APDL.  A layout drawing of the lower leg is provided (in Blackboard) along with an IGES file containing the detailed geometry.

Submit a report of your findings.  You should outline the rationale for the finite model in regard as to how it best represents the physical structure.  All relevant results should be reviewed including any used to verify the validity of the model. Conclusions should be drawing from the results of the discussion.  All externally accessed information should be fully referenced.

1. Write an introduction on what finite element analysis is or the history of finite element analysis.
2. Write a “How to in Ansys…”. The report is about understanding how to apply finite element analysis and demonstrating that you understand the results obtained.
3. Write conclusions that comment on finite element in general (e.g. finite element is really good, finite element is really bad, etc.).