Character Simulation Research Of Multi-Leaf Spring Based On FEM

Leaf spring is an elastic component often used in dependent-type suspension on modern vehicles. It's function is transferring the force and moment from wheel to body, decreasing the impact load from road surface, attenuating the vibration which caused by the impact load, assuring the regular running of the vehicle. Leaf spring has simpleness configuration and low manufacturing cost, it's easy to maintain and as a guide mechanism of the suspension. Those advantages makes leaf spring be used wildly, and its fatigue and damp characteristics are vital to the reliability and security in the vehicle riding. This paper implement a CAE performance analysis based on the FE analysis of one type multi-leaf spring.By using the UG/GRIP, a parametric 3D model of each leaf spring which at free condition is constructed. According to the design parameter of this multi-leaf spring, such as dimension, curvature and arc high, a solid model leaf is constructed automatically. The parametric modeling can predigest the modeling task and provide a convenient way to modify or construct new solid model of multi-leaf spring.Making use of the solid model, a FE model of the multi-leaf spring is constructed by ANSYS'mapped mesh. To figure out the nonlinear contact condition of the leaf spring, we use contact element type to simulate the contact region of leaf spring, and treat with the elements'attributes properly. A simulation of multi-leaf spring assemble is performed and the initial stress produced during this process is displayed, compare it to the theoretic value to confirm the FE model. Then simulate the stiffness test and calculate the stiffness value, compare it to real test value.Using the S-N curve, and considering the influence on fatigue characteristics of the leaf spring real feature, a fatigue analysis simulation is performed with the help of ANSYS'fatigue module. Detecting the fatigue dangerous area and calculating the fatigue life of the multi-leaf spring, then compare it to test value. According to the theory of mechanical vibration, analyze the damp characteristic of the leaf spring and calculate the damp scale.This paper use FE and parametric modeling method, implement an stiffness, fatigue and damp simulation of one type multi-leaf spring, and compare the simulating results with the test results. The research reveal that the FE method has high accuracy in analyzing characters of leaf spring and the S-N curve method can predict the fatigue dangerous area and fatigue life well and truly. The meanings and conclusions can effectively instruct the design of multi-leaf spring system.