摘要
金属材料构件表面/亚表面损伤严重降低构件的表面完整性。针对早期力学损伤的评价难题,研究了基于临界折射纵波(critically refracted longitudinal wave,LCR)的无损评价方法。以纯铁低周疲劳损伤为对象,分析其循环应力-应变响应及组织形貌演变,建立了LCR波归一化幅值与疲劳加载周次的对应关系,并与常规超声脉冲回波法对比分析。结果表明:对于薄片状试样,LCR波在测试过程中的稳定性显著高于常规超声脉冲回波法,且前者归一化幅值与加载周次呈单调递减关系,后者归一化幅值和超声衰减系数与加载周次关系并不单调,证实LCR波适于工程构件表面/亚表面力学损伤无损评价。
The surface/subsurface damage of metal engineering components degraded the surface integrity seriously.A nondestructive evaluation method based on critically refracted longitudinal wave(LCR)was proposed to overcome the difficulty in early mechanical damage evaluation.The low-cycle fatigue damage of pure iron was studied,and the cyclic stress-strain response and the surface morphology evolution were analyzed.Furthermore,the relationship between the ultrasonic response characteristics of LCR wave and cyclic loading cycles was established,which was also compared with the conventional ultrasonic pulse-echo method.Results showed that the repeatability of LCR waveform for sheet samples was significantly strengthened.The normalized amplitude of LCR wave presented monotonous decrement with the increasing loading cycles,while those of conventional ultrasonic method were not,which proved that LCR wave was a good choice for nondestructive evaluation on surface/subsurface mechanical damage of engineering components.
作者
罗忠兵
王新禹
孟亦圆
金士杰
陈军
林莉
雷明凯
LUO Zhong-bing;WANG Xin-yu;MENG Yi-yuan;JIN Shi-jie;CHEN Jun;LIN Li;LEI Ming-kai(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116085,China)
出处
《材料保护》
CAS
CSCD
北大核心
2019年第9期67-71,共5页
Materials Protection
基金
国家自然科学基金(51775087和51405061)
国家重点基础研究发展计划资助项目(973计划,2015CB057306)
关键词
纯铁
表面/亚表面
疲劳损伤
临界折射纵波
脉冲回波
pure iron
surface/subsurface
fatigue damage
critically refracted longitudinal wave
pulse echo
