摘要
为提高焊接残余应力钻孔法测量结果的可靠性,需分析其测量过程中的误差因素,依据误差传递理论推导了由应变误差与释放系数误差传递给最终测量结果的误差公式,并由测量过程中的误差因素建立了一条影响最终测量结果的误差链.以2A12高强铝合金VPPA-MIG复合焊接板材为试验对象,定量分析了误差链中的弹性模量误差、贴片误差和应变读数取值时间误差传递到最终结果中的相对误差.结果表明,由弹性模量误差传递到残余应力σ_1,σ_2中的相对误差均很小;由贴片误差传递到残余应力σ_1,σ_2和Φ角中的相对误差在贴片24 h后均降为0%;由应变取值时间误差传递到残余应力σ_1,σ_2和Φ角中的相对误差在应变释放150 min后均降为0%.
In order to improve the reliability of measuring results of welding residual stress,it is needed to analyze the error factors in the process of the residual stress measured by hole drilling method.The error expression where strain error and release coefficient error are passed to the final measuring result has been derived according to the theory of error propagation and one error chain that affects the accuracy of final measurement result is established by the influencing factors of actual measurement error.Taking 2A12 high strength aluminum alloy plates after VPPA-MIG hybrid welding into measuring experiment,the relative error of final measuring that results from the error of elastic modulus,the error of strain gauge paste and the time error of strain reading in the error chain are quantitatively analyzed.The relative error of residual stressesσ1 andσ2 from the error of elastic modulus are both very small.The relative error of residual stressesσ1,σ2 andΦangle from the error of strain gauge paste all reduce to 0%after the strain patch is pasted for 24 hours.The relative error of residual stressesσ1,σ2 andΦangle from the time error of strain reading all reduce to 0%after 150 minutes of strain release.
作者
甘世明
韩永全
陈芙蓉
GAN Shiming;HAN Yongquan;CHEN Furong(Materials Forming Key Laboratory,Inner Mongolia University of Technology,Hohhot 010051,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2018年第10期48-53,131,共7页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51665044)
