低周疲劳下对接焊缝累积塑性损伤的金属磁记忆表征研究  

Research on characterization of cumulative plastic damage in butt weld under low cycle fatigue using metal magnetic memory

作　　者：杨熠奕 马小平[2] 苏三庆[3] 王威[3] YANG Yiyi;MA Xiaoping;SU Sanqing;WANG Wei(Shanxi College of Communications Technology,Xi'an 710018,China;Research Institute of Architectural&Planning Design/Research Center of Transit Oriented Development,China Railway First Survey and Design Institute Group Co.,LTD.,Xi'an 710043,China;School of Civil Engineering,Xi'an University of Architecture&Technology,Xi'an 710055,China)

机构地区：[1]陕西交通职业技术学院,西安710018 [2]中铁第一勘察设计院集团有限公司建筑与规划设计研究院/TOD研发中心,西安710043 [3]西安建筑科技大学土木工程学院,西安710055

出　　处：《材料科学与工艺》2024年第6期87-98,共12页Materials Science and Technology

基　　金：国家自然科学基金面上项目(51878548,51578449);中铁第一勘察设计院集团有限公司科研开发项目(2022KY51ZD(ZNJC)-03);陕西高校青年创新团队;2023年陕西交通职业技术学院科研创新团队基金项目;陕西省自然科学基础研究计划(2024JC-YBQN-0609);陕西交通职业技术学院院级课题资助项目(YJ23003).

摘　　要：地震载荷下的钢构件,因低周疲劳所致的塑性损伤累积而诱发严重的断裂破坏。金属磁记忆作为一种新兴无损检测技术,已被证明可用于钢构件的疲劳损伤表征。为改善既有力-磁耦合理论及数值模拟方法的局限性,实现焊接件塑性损伤的无损评估,本文利用磁记忆技术对低周疲劳下对接焊缝的累积塑性损伤进行了表征分析。针对焊接构件的非均匀磁化问题,基于既有理论模型并改进模拟方法,实现了低周疲劳下焊接件的力-磁耦合有限元模拟。同时,通过Q345qC焊接件的低周疲劳及磁信号检测实验,分析了法向磁信号H_(SF)(z)及其特征参数的变化规律,由对比实验与模拟结果可以发现,磁信号曲线在焊接位置均出现明显的突变现象,磁信号峰-谷梯度K_(p-v)随累积塑性损伤D的增大均呈指数递减,二者平均误差不超过5%,证明了模拟方法的准确性。在此基础上,建立了低周疲劳下焊接件K_(p-v)与D的量化关系,验证了磁信号峰-谷梯度具有表征钢材塑性累积损伤程度的潜在可能,可为定量评价焊接试件的塑性损伤提供参考。Steel members under seismic load often suffer from severe fracture damage due to the accumulation of plastic damage caused by low cycle fatigue.As an emerging nondestructive testing technology,metal magnetic memory has been proven to be useful for the fatigue damage characterization of steel members.In order to overcome the limitations of current magneto-mechanical coupling theories and numerical simulations,and enable nondestructive evaluation of plastic damage in welded specimens,magnetic memory technology was used to characterize the cumulative plastic damage of butt welds subjected to low cycle fatigue.A magneto-mechanical coupling finite element simulation of welded specimens was conducted to address the issue of non-uniform magnetization in welded components,utilizing an improved simulation method based on an existing theoretical model.Moreover,the variation law and characteristic parameters of normal magnetic signal H_(SF)(z)on the surface were studied through low cycle fatigue and magnetic signal detection tests for the Q345qC welded specimen.Based on the experimental and simulation results,it is clear that the H_(SF)(z)signal curve exhibits a noticeable sudden change at the welding location.Additionally,the gradient of the peak-valley(K_(p-v))decreases exponentially with the progressive accumulation of plastic damage(D).The experimental and simulation methods have an average error of less than 5%,demonstrating their accuracy.A quantitative relationship for K_(p-v)-D in welded specimens was established,validating that K_(p-v)has the ability to reflect the cumulative plastic damage of steel when subjected to low cycle fatigue.This provides a benchmark for the quantitative evaluation of cumulative plastic damage of welded parts.

关 键 词：低周疲劳 累积塑性损伤 金属磁记忆 力-磁耦合 损伤表征 

分 类 号：TU115.28[建筑科学—建筑理论]