Method for predicting residual stress field of surface plane of mechanical part

Abstract

The present invention discloses a method for predicting a residual stress field of a surface plane of a mechanical part. The method comprises the following steps of: 1) establishing a binary n-order trigonometric polynomial model of a primary residual stress component; 2 ) performing preliminary test and analysis so as to determine the value of model order n; 3 ) determining the number of test points and a test scheme according to the model order n, and performing the test; 4 ) performing matrix form collation on the model according to a prediction model and a test result, so as to solve a coefficient of the model; 5) solving coefficients of other residual stress component prediction models according to the test result of the residual stress components, the solved model coefficient and a self-equilibrium condition; and 6) representing the residual stress field of the surface plane vividly. According to the method provided by the present invention, test blindness is prevented; the solving process of the established model is simple; and the self-equilibrium characteristic of the residual stress field of the surface plane is fully taken into account and can be input into a finite element analysis program conveniently, so that the method has a distinct advantage in prediction of the residual stress field of the surface plane of the mechanical part with the manufacturing process or use process undisclosed in detail.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing, and more specifically relates to a method for predicting the surface plane residual stress field of mechanical parts. Background technique [0002] It has been proved in theory and practice in various disciplines that most of the damage process of mechanical parts starts from the surface plane, and the residual stress is an important indicator of the quality of the machined surface plane of the part. Different, it has a significant impact on the static mechanical properties, stress corrosion performance, fatigue resistance, dimensional stability and service life of the material. The quality of the residual stress on the surface of the part directly affects the working performance and working performance of the part or machine. life. For a long time, the research on the surface residual stress of parts has been a hot topic for many researchers and engineers. [0003] At present, ...

AI Technical Summary

Problems solved by technology

However, most of the experimental methods usually use the least squares method to fit the data of a limited number of discrete points to obtain a complete residual stress field. Due to the randomness of the location and number of test points, the predicted stress The field may not meet the self-balancing conditions, resulting in low prediction accuracy, and it is not easy to input the finite element analysis program; the finite element method needs to know the part manufacturing process, but the part manufacturing process is complicated, it is extremely difficult to describe, and the characterization is laborious and accurate The accuracy is not easy to guarantee, and the residual stress field cannot be predicted when the manufacturing or use process of the part cannot be known in detail; the stress function method and the inherent strain method are a kind of function that assumes that the residual stress component or strain component is a certain form, and is carried out through boundary conditions. The solution method, this method needs to repeatedly try the function for debugging, but has not been widely used

Images