Study On Nonlinear Stiffness And Relaxation Behavior Of Canted Coil Spring

At present,the canted coil spring,because of its special nonlinear stiffness characteristics,is widely used in high voltage power connection and high performance sealing equipment.The relaxation phenomenon is the main form of the spring failure.It is very important to analysis the stress relaxation performance of the canted coil spring to make sure it can meet the work demand for a long time in high voltage connector or high performance seal.In this paper,it going to improves the nonlinear stiffness theory of the spring and establishes the stress relaxation theory of the spring based on the mathematical model of the canted coil spring.The research contents are as follows:(1)Nonlinear stiffness theory of the canted coil spring.Based on parametric modeling,a set of effective theoretical methods for calculating the stiffness of canted coil spring is established by using single canted coil spring as the research object.The parametric analysis of the spring structure is carried out to obtain the impact of the spring pitch,inclination angle,diameter and coil width on the stiffness of the structure.Compared with the finite element method,the method of calculating the spring stiffness is more efficient,and it is helpful to the cognition of the nonlinear mechanism of the canted coil spring,which provides the theoretical guidance for the optimization design,production and detection of the inclined coil spring.(2)Stress relaxation theory of the canted coil spring.Firstly,by analysising the relationship between creep and stress relaxation,The stress relaxation equation based on Altenbach-gorash-naumenko creep theory which adapted to the large stress range was established.A differential evolutionary algorithm is used to fit the material parameters of the theory.Secondly,the stress relaxation results of the canted coil spring are obtained by using multidimensional creep theory and energy method to solve the stress in the spring.The method of predicting the stress relaxation life and prolonging the life of the canted coil spring is also analyzed.