基于变形力监测数据的残余应力场推断和表征方法

A New Method for Inferencing and Representing a Workpiece Residual Stress Field Using Monitored Deformation Force Data

残余应力是材料的基本属性之一,与零件的几何形状、尺寸稳定性和疲劳寿命直接相关。针对具有高精度要求的大型零件,其残余应力场的准确测量和预测一直是一个挑战。目前的残余应力场测量技术可以分为基于应变的破坏性方法和基于射线、声波等物理量的非破坏性方法,但均受限于测量效率和精度,且难以得到工件的整体残余应力场。针对以上问题,本文提出了一种基于加工过程中的变形力监测数据推断工件整体残余应力场的新方法。本方法通过能够反映去除材料后不平衡残余应力场整体效应的变形力推断零件的残余应力场。利用虚功原理建立了变形力与残余应力场之间的力学关系,并引入正则化方法求解整体残余应力场。理论验证和实际实验测试结果均表明,该方法对于大型结构件的残余应力场测量具有可靠的精度和灵活性。在数字化和智能制造的趋势下,该方法的基本原理为利用加工监测数据预测和补偿由残余应力引起的零件加工变形提供了重要参考。

The residual stress inside stock materials is a fundamental property related to the quality of manufac-tured parts in terms of geometric/dimensional stability and fatigue life.For large parts that must meet high-precision requirements,accurately measuring and predicting the residual stress field has been a major challenge.Existing technologies for measuring the residual stress field are either strain-based mea-surement methods or non-destructive methods with low efficiency and accuracy.This paper reports a new non-destructive method for inferencing the residual stress field based on deformation forces.In the proposed method,the residual stress field of a workpiece is inferred based on the characteristics of the deformation forces that reflect the overall effect of the unbalanced residual stress field after material removal operations.The relationship between deformation forces and the residual stress field is modeled based on the principle of virtual work,and the residual stress field inference problem is solved using an enforced regularization method.Theoretical verification is presented and actual experiment cases are tested,showing reliable accuracy and flexibility for large aviation structural parts.The underlying prin-ciple of the method provides an important reference for predicting and compensating workpiece defor-mation caused by residual stress using dynamic machining monitoring data in the context of digital and intelligent manufacturing.