The Structural Analysis And The Key Technology Research Of A Balanced Suspension Taper-leaf Spring

With the development and progress of society in China, comfort and vehiclepass ability of the automobile, especially for heavy trucks, have become increasinglydemanding. Leaf spring balanced suspension in heavy truck can ensure the vehicleride comfort and bandling stability, while meeting the requirements of improvingtransport efficiency. Because of its low cost, simple structure, easy maintenance, etc,leaf spring is widely used in balance suspension. On account of its geometrynonlinear, contact nonlinear etc．， the precise design of leaf spring becomesdifficult． The development of advanced contact dynamics and CAE technologymakes it possible to solve this problem．This paper takes a heavy truck as the platform. According to the presentsituation that automobile little leaf spring is designed and produced in view of ourcountry， and utilizing the well-developed research design measure at present,research has been done on the following aspects:(1) The mathematical model of leaf spring is researched, and the calculationmethod of trapezoid tapered leaf spring is in-depth understood. Then the taper-leafspring mathematical model is established, the stiffness, strength and othercalculation methods for taper-leaf spring is studied, and then focus discussion ontaper-leaf spring to establish three-dimensional model.(2) The basic analysis methods of advanced contact dynamics theory aresummarized．Considering large deformation，interleaf contact simultaneously, theFEA model of one taper-leaf spring is built using Ansys based on nonlinear finiteelement for continua and structures．The stress and strain distribution and stiffnessproperties are calculated and analysed under three conditions of clamping, full loadand the maximum.(3) The taper-leaf spring of balanced suspension is optimized and designed.First of all, to meet the premise of the design requirements of balance suspension,optimization design tool for structural parameters is done on the application ofMatlab to determine the appropriate structure parameters of the spring; then finiteelement analysis is done. Finally, the comparison of structure properties between theoriginal structure of balanced suspension’s spring and the optimal one is carried on,the bench test results show that optimization design of the leaf spring meets thedesign requirements, and the model is high accuracy.(4) By using nonlinear finite element method, the effect of different frictioncoefficient on the strength, stiffness characteristics of the taper-leaf spring is studied with the application of Ansys software. The reference is provided to the precisedesign of the taper-leaf spring.Through the performance test of the spring, the actual value of the deformationand the elastic stiffness are determined. Compared the results of experiment withfinite element analysis results, it shows that they are in good agreement, whichverified the accuracy of the leaf spring finite element analysis model and theanalysis method.