Computational Modeling Of Taper Leaf Spring And Its Performance Research

Leaf Spring is a common elastic component in the dependent suspension. It transfers the force and moment from the wheel to the body, decreases the impact load from the road surface, attenuates the vibration due to this impact load, and assures the regular running of the vehicle. Leaf spring also acts as a guide mechanism of the suspension, which simplifies the structure design of the suspension and the maintenance, and decreases the production cost. In order to take full advantage of the material, the leaf spring is designed as a beam of constant strength. One of the examples is taper leaf spring. In order to improve the design of the taper leaf spring, a computational model is constructed and CAE performance analysis is implemented.According to the technical drawing of taper leaf spring, a parametric model is constructed. Specifically speaking, by inputting the parameters such as dimensions, curvature and arc high, a solid model of each leaf spring is constructed automatically and respectively. The parametric method simplifies the procedure of model construction and the coming simulation research.With the help the solid model, an FE model of the taper leaf spring is constructed by mapped mesh. The friction between leaves is simulated by adding contact elements to the contact surface of each leaf spring and by setting relevant parameters. Checking the assembly stress and the spring stiffness are the two methods for the model validation. After the assembly of the taper leaf spring, the assembly stress is calculated and compared to the theoretic value. The stiffness is calculated in the elastic characteristic simulation and is compared to the experimental value. A formula of stiffness calculating is deduced according to material mechanics.A fatigue analysis simulation is implemented with the help of the S-N curve of similar material. The fatigue dangerous area is located and the fatigue life is calculated, which is compared to the experimental result for the validation. The relation between the thickness of the leaf spring and the fatigue life is discussed.The method of damp characteristic simulation is designed considering the feasibility of validating by the experiment. First the whole assembly of leaf spring is compressed down at a certain value. The deformation of each leaf is then recorded. After that each leaf is compressed down respectively according to the records. The equivalent damp is finally calculated based on the difference work of these two situations. The relation between the frictional coefficient of the leaf spring and the equivalent damp is discussed. The simulation result offers a parameter for the design of the damper in the suspension.