Automotive semi-elliptic leaf springs are used in suspensions of light and heavy commercial vehicles and passenger car applications. The design of the spring consists of a number of leaves called blades. The blades are made of varying lengths and are provided a curvature so that they become straight under the application of loadings under service conditions. The blade at the bottom is the master blade and has eyes on its ends to secure the assembly. The blades mounted on the master blade are called graduated leaves. All the blades are assembled together by means of fasteners and associated fittings. The spring when mounted on the axle of the vehicle takes up the entire vehicle load, with this load resting on the leaf spring assembly.
The physics involved in the simulation are complex and can be summarized as follows:
- Non-linear material property of the steel material has to be included.
- To realistically model the service behavior of the spring assembly non-linearity relating to the presence of different blades have to be taken into account.