压入能量差法测试二向残余应力  

Determination of biaxial residual stresses via indentation energy difference method

作　　者：彭伟[1] 蒋文春[1] 杨滨[1] 孙广华 邵晓明 孔德胜 王豪宇 李玫蓁 PENG Wei;JIANG WenChun;YANG Bin;SUN GuangHua;SHAO XiaoMing;KONG DeSheng;WANG HaoYu;LI MeiZhen(College of New Energy,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)新能源学院,青岛266580

出　　处：《中国科学：物理学、力学、天文学》2023年第1期4-14,共11页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:U21B2076);山东省自然科学基金(编号:ZR2019BEE050)资助项目。

摘　　要：本文提出了一种利用有残余应力和无残余应力作用下的压入能量差计算二向残余应力的新方法,采用努氏压头分别沿二向应力方向压入,以压入过程加载力-压入深度(F-h)曲线积分得到的压入能量作为计算参数,无需观测压痕形貌即可获得二向应力分量.首先构建了压入过程功-能转化模型,从能量角度解释F-h曲线随残余应力变化的原因.通过有限元方法分析不同幂律硬化材料在残余应力作用下的能量演变,建立了单向残余应力作用下的压入能量差计算公式.同时,计算结果表明努氏压头的压入能量差具有叠加特性和方向特性.利用该特性可实现将任意二向残余应力转化为两个等效单向残余应力,进而将其分别代入单向残余应力的压入能量差计算公式即可获得二向应力分量.搭建了压入法测试装置,与压痕应变法对比测试取得了较为吻合的残余应力分布结果.In this study, a novel method is proposed to estimate biaxial residual stress(RS) by using the indentation energy difference between the stressed and the stress-free samples. A Knoop indenter is applied along the directions of principal stresses, and the indentation energy obtained from the load-depth(F-h) curves is used as the calculation parameter without observing the indentation morphology. A work-energy transformation model is constructed to explain the change in the F-h curve with the RS in terms of energy. Then, the finite element analysis of different power-law hardening materials under different RS combinations is implemented to study the energy evolution. Consequently, the formula for calculating the indentation energy difference under a uniaxial RS is established. Meanwhile, the indentation energy difference of the Knoop indenter exhibits superposition and direction characteristics, which can be used to convert the indentation energy difference under a biaxial RS into the sum of that under two equivalent uniaxial stresses. Through this conversion, the two stress components can be calculated from the two indentation energy difference formulas. An indentation testing device is developed to verify the proposed method. The results obtained using the proposed method agree well with those obtained using the indentation strain-gage method.

关 键 词：残余应力 压入法 努氏压头 能量法 

分 类 号：O344[理学—固体力学]