华南理工大学学报(自然科学版) ›› 2019, Vol. 47 ›› Issue (12): 25-31.doi: 10.12141/j.issn.1000-565X.180299

• 机械工程 • 上一篇    下一篇

盲孔法测曲面残余应力时释放系数的数值模拟

马小明 欧清扬
  

  1. 华南理工大学 机械与汽车工程学院,广东 广州 510640
  • 收稿日期:2018-06-15 修回日期:2019-08-08 出版日期:2019-12-25 发布日期:2019-11-02
  • 通信作者: 马小明(1962-),男,副教授,主要从事核电装备焊接残余应力测试、超高压反应器自增强再处理技术、过程设备 安全检测与失效分析、液化天然气技术等研究. E-mail:mmxmma@scut.edu.cn
  • 作者简介:马小明(1962-),男,副教授,主要从事核电装备焊接残余应力测试、超高压反应器自增强再处理技术、过程设备 安全检测与失效分析、液化天然气技术等研究.
  • 基金资助:
    国家科技重大专项项目( 2015ZX06002007)

Numerical Simulation for Hole-drilling Strain Gage Method Applied on Curved Surface

MA Xiaoming OU Qingyang#br#   

  1. School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2018-06-15 Revised:2019-08-08 Online:2019-12-25 Published:2019-11-02
  • Contact: 马小明(1962-),男,副教授,主要从事核电装备焊接残余应力测试、超高压反应器自增强再处理技术、过程设备 安全检测与失效分析、液化天然气技术等研究. E-mail:mmxmma@scut.edu.cn
  • About author:马小明(1962-),男,副教授,主要从事核电装备焊接残余应力测试、超高压反应器自增强再处理技术、过程设备 安全检测与失效分析、液化天然气技术等研究.
  • Supported by:
    Supported by the National Science and Technology Major Project( 2015ZX06002007)

摘要: 盲孔法是一种测试表层残余应力的高精度机械方法,但现行盲孔法标准的分析和研究都是基于大平板试样,对于待测部位像角焊缝或管表面等非平面的情况,表面形状会对残余应力测试造成多大的影响是文中研究的重点. 在材料参数固定的情况下,形状因素直接影响应变释放系数 a、b 的变化. 文中首先基于弹性力学,对比分析平面、凹凸球面模型的几何钻孔截面,发现三者的应力释放差异是由于应变片至孔边的距离 Dh 不同造成; 随后通过 ANSYS 有限元模拟不同曲率的凹、凸球面模型的钻孔过程,以量化应力释放差异,该模拟结果与 Dh 随孔深变化的规律一致. 另外,基于球面的 a、b 系数变化结果,提出了适用于包括柱面等所有曲面的 a、b 系数计算方案.

关键词: 盲孔法, 残余应力, 释放系数, 数值模拟

Abstract: Hole-drilling method is a mechanical way with high accuracy to measure residual stress on surface. The existing analyses and studies on hole-drilling standard are wholly based on large plane surface,while there is little research on surfaces with curvature,such as the surface of fillet weld or tubes. Thus the objective of this study is to clarify the influence of surface shape on the residual stress level. When the material parameters are fixed,the sur- face shape have direct influence on the calibration constants a and b. Based on the mechanics elasticity,the com- parative analysis of borehole cross-section of the plane surface and spherical surface were carried out. The result shows that stress relief difference is caused by factor Dh,which is the distance from the strain gauge to the edge of the hole. Then the drilling process of concave and convex spherical models with different curvatures were simulated by finite element model ANSYS to quantify the stress relief of different models. The simulation results are consistent with the changing regularity of Dh and hole depth. In addition,based on the results of spherical coefficients,a cal- culation scheme for general revolution surface was presented,which may be applied to all kinds of surfaces includes cylinders.

Key words: hole-drilling method, residual stress, release coefficient, numerical simulation