Establishment of theoretical model of composite leaf springs by using the mechanics of composite materials

Lightweight design is an inevitable trend in automobiles because of its energy saving and emission reduction properties. Composite leaf springs possess light weight and high fatigue life and are both comfortable and safe to use. This type of spring could be an effective substitute to conventional steel leaf springs. Stiffness, a basic performance parameter of automobile leaf springs, directly affects the handling stability and riding comfort of vehicles. Stiffness matching of composite leaf springs is important. In this paper, the principle of leaf spring stiffness is studied in-depth from the point of view of the mechanics of composite materials. A theoretical model is established for precise calculation of composite leaf spring stiffness. This model resolves the slow speed of traditional methods for determining finite element stiffness; hence, the proposed model can be used to optimize the design of composite leaf springs. Numerical simulation results of the model are compared with the finite element simulation and experimental results to verify the accuracy of the model. Finally, sensitivity analysis is performed on key design parameters that affect the stiffness of composite leaf springs to provide a guide for stiffness matching.