Research On Mechanical Characteristic And Fatigue Strength Of Leaf Spring

Leaf spring as the suspension is widely used in all kinds of cars. But considering the geometric nonlinearity and contact nonlinearity factors of the leaf spring, traditional mechanics analysis method to establish the precision of leaf spring analysis model Need to improve, especially for stress analysis.This paper has introduced the traditional calculation method of leaf spring stiffness and stress, such as,the "common curvature method","concentrated load method" and "improved concentrated load method".Introduces the modeling method based on multi-body dynamics and modeling method based on finite element method. With finite element method and the traditional calculation method to calculate the stiffness of leaf spring, compares several modeling methods of modeling accuracy.In this paper, a little piece of finite element model of variable cross-section leaf spring, model has been set up. Boundary condition in accordance with the national standard GB/T19844-2005the test conditions specified in the agreement; By considering the different coefficient of friction, stiffness curve is obtained under three kinds of the coefficient of friction. Were reviewed and the stress distribution in the analysis, get the specify point stress under different load curves.This paper Fatigue life analysis method is studied, and the application of relevant theory of fatigue parts life S-N curve are obtained; The national standard GB/T19844-19844cyclic stress level, got a little piece of variable cross-section steel plate spring fatigue life distribution of the cloud.In the last, an experiment has been performed, the standard refer to specification of national standard GB/T19844-2005, carries on the static load of the leaf spring stiffness test and fatigue test. Under the specified load is obtained by stiffness test, the deformation and stress distribution; Is obtained by fatigue test, the fatigue life of the plate spring and fracture position. Results compared with the finite element results, has the very good consistency. Verified the correctness of the finite element method of leaf spring model is established.