Composite Leaf Spring Damping Analysis And Matching With Suspension System

Since 21 Century, with development of social science, technology, economy and cultural, the car has become a necessity for every family. The requirements of automobile are not only dynamics, comfort, but also safety, economical and environmentally friendly. Lightweight of automobile has become inevitable trend of the industry. With the same dynamics, composite leaf spring lighter than steel spring by 40%, composite leaf spring is also corrosiveness resistance, oxidation resistance, which fatigue life is twice longer tan steel spring. At the same time, it has damping characteristics, which make a great contribution to suspension damping effect, so it has good application value and broad market prospect. However there are few researches of composite leaf spring for it’s damping characteristics, and much fewer researches for it’s damping match of suspension system, can’t meet the needs of composite leaf spring development.The research object of this paper is fiber reinforced resin matrix composite leaf spring, comes from a research with an automobile manufacturer cooperation projects. In this paper, we use finite element analysis method, study damping characteristics and its influencing factors of composite leaf spring, the study of composite leaf spring and damping matching method of suspension system, the main contents are the following parts:Reading related papers, analyzing the mechanization of composite leaf spring damping, and establish the composite damping model to determine how to simulate and test.According to the structure parameters of the leaf spring, establish the 3D models and meshes in the finite element by the finite element software, then mechanical properties of materials are given; simulate composite laminates and spring modal, use the model shape to find the sensor arrangement and excitation point of composite laminates and spring assembly modal to test, verify the correctness of the modal simulation method, and the analysis of influencing factors; based on this, make composite laminates and spring damping test and added the damping test data parameter to composite leaf spring damping model of finite element simulation analysis, get the result of damping ratio ξ, and compared with experimental results. Optimizing parameters of the simulation model and finding influencing factors. Then make dynamic stiffness test to calculate the damping of leaf spring which changes with the time, frequency and amplitude by the test of dynamic damping value of the stiffness of the "hysteresis loop". Finally, match the composite leaf spring equivalent vibration absorber model with the suspension system, and study its influence on the vibration reduction performance of suspension system, make a matching scheme.In this paper, using the theory analysis, simulation and test, composite leaf spring damping characteristics are studied in detail, and have the suspension system damping matching method which provide theory support and ideas for composite leaf spring design and development, improvement and optimization.