Introduction to analytical method of spring stress

At present, the widely used calculation formula of spring stress and deformation is derived from the mechanics of materials. Without certain practical experience, it is difficult to design and manufacture high-precision spring. With the increase of design stress, many previous experiences are no longer applicable. For example, when the design stress of the spring is increased, the helix angle will increase, and the fatigue source of the spring will be transferred from the inside to the outside of the coil. Therefore, precise analytical techniques must be used. The widely used method is finite element method (FEM).

In recent years, the finite element method design method of spring has entered the practical stage, and many valuable reports have appeared, such as the influence of helix angle on spring stress, the relationship between stress and fatigue life calculated by finite element method, etc.

Reliability design is a series of analysis and design techniques used to ensure the reliability of the designed products. Its task is to make the designed products reach the specified reliability target value on the basis of predicting and preventing the possible failure of products. It is a supplement and improvement of traditional design method. Spring design has made some progress in the use of reliability technology, but to further improve, it needs data development and accumulation.

The optimization design is also introduced in the design process of spring. The spring structure is relatively simple, the function is simple, and the parameters affecting the structure and performance are saved. Therefore, the designer has long used the analytic method, graphic method or graphic analysis method to seek the optimal design scheme, and achieved certain results. With the development of computing technology, the optimization design of nonlinear programming with computer has achieved good results.