A Coil Spring Life Evaluation Method Based on Monotonic Regression Theory

Abstract

The present invention provides a coil spring life evaluation method based on the monotonic regression theory, and the specific implementation steps are as follows: Step 1: Correct the upside-down data based on the monotonic regression theory; Step 2: Estimation of coil spring stress relaxation model parameters; Step 3: Model fitting Goodness test; Step 4: Coil spring life evaluation. The present invention corrects the upside-down phenomenon in the initial test data for the coil spring stress relaxation test data, and uses least squares to estimate the parameters of the coil spring stress relaxation model, and then carries out F-test, t for the coil spring stress relaxation model ‑test and correlation coefficient test ensure the applicability of the stress relaxation model and the accuracy of coil spring life evaluation; the method proposed by the present invention is simple and easy to calculate, easy to implement, and the evaluation result is more stable, which is convenient for engineering and technical personnel to master and use, and is easy to apply promote.

Description

technical field [0001] The invention provides a coil spring life evaluation method based on monotone regression theory, which is a coil spring life evaluation method based on monotone regression theory and F-test, t test and correlation coefficient test theory. According to the coil spring stress relaxation test data, it corrects the upside-down data through the adjacent reverse order combination method (The Pool-Adjacent-Violators Algorithm, referred to as PAVA method) in the monotonic regression theory, and performs least squares on the parameters of the coil spring stress relaxation model. Estimate, and use F-test, t-test and correlation coefficient test theory to verify the applicability of coil spring stress relaxation model, and finally complete the evaluation of coil spring life. This patent applies to related technical fields such as product life assessment. Background technique [0002] A coil spring is a scroll spring made of spring steel. It is fixed at one end a...

AI Technical Summary

Problems solved by technology

[0009] In actual work, due to the constraints of test time and test cost, the test sample size n cannot be too large. Therefore, the test results will be greatly affected by the individual differences of coil springs and measurement errors, and sometimes there will be This is inconsistent with the characteristic that the elastic performance of the coil spring decreases with time. It is called data inversion in engineering. The serious inversion phenomenon will cause great errors in the calculation results and greatly affect the elasticity of the coil spring. Results of Performance and Lifetime Evaluation

In addition, in engineering applications, a fixed coil spring stress relaxation model is usually used directly to describe the change of coil spring elastic properties, lack of statistical testing of model applicability, and the accuracy of coil spring elastic properties and life evaluation results cannot be guaranteed

Images