磁记忆信号与应力之间的关系

Relationship between magnetic memory signal and stress

摘要:

为明确磁记忆信号与工作应力和残余应力之间的对应关系,对Q235低碳钢板状试件进行了静载拉伸实验.利用TSC-1M-4型磁检测仪,研究了光滑试件和人工缺陷试件表面法向磁场强度在不同工作载荷下及卸载后的变化规律.结果表明:磁记忆信号与工作应力之间具有较好的相关性,利用相邻两磁信号之间的相关系数可以判断试件是否处于某种临界或极限状态;塑性变形前后的离线磁信号并无明显区别,但断裂后的磁信号及梯度曲线可用于准确识别断裂位置.

Abstract:

To determine the relationship between magnetic memory signal and working stress as well as residual stress,static tensile tests on plate specimens made of Q235 low carbon steel were performed.The variation regularities of normal magnetic field intensities on the surfaces of specimens with and without artificial defects under different working loads and after unloading were investigated respectively,using the magnetometer TSC1M-4.The test results show that there is a good correlation between the magnetic memory signal and working stress,and whether the specimen is in a certain critical or limit condition can be predicted via the correlation coefficient between two adjacent magnetic signals.The magnetic memory signals before and after plastic deformation after unloading can not be distinguished,but the fractured magnetic memory signal and the corresponding gradient curve have obvious characteristics to be used to identify fracture zones.