Q235B钢板拉伸损伤试验的声发射特性

Acoustic emission characteristics of Q235B steel plates' tensile damage tests

制作完整和焊接两种Q235B板材试样,利用声发射技术对其拉伸过程的损伤特性进行监测,根据获得的拉伸过程载荷时间历程曲线和材料损伤声发射信号,结合金属材料力学行为特性,对材料损伤声发射信号的幅度、振铃计数以及能量等参数进行分析,获得了材料塑性屈服、强化变形以及断裂等损伤阶段所表现出的声发射特性,通过对声发射信号撞击幅度和能量的统计分析,初步得到了不同损伤阶段所对应的声发射参数分布范围。对比分析完整和焊接两种试样损伤所表现出的不同声发射特性,结果表明声发射特性参数能够很好地描述焊接对材料力学特性的影响,并能以声发射参数"双峰"分布的形式从微观上反映焊接对试样屈服所造成的影响。实验结果为声发射技术应用于起重机结构状态监测提供了参考数据。

Two Q235 B plate tensile samples with and without weld joint were fabricated and their tensile damage properties were monitored by using acoustic emission technology（ AET）. Based on the loading time-history curves and the material damage acoustic emission signals during tensile tests,combined with the metal material mechanical behavior,the acoustic emission characteristics of the plates during plastic yielding,deformation strengthening and material fracture,etc.damage stages were obtained by analyzing AE amplitude,ringing counts and energy,etc. parameters. The AE parameter distribution ranges for different damage phases were also preliminarily gained using the statistical analysis of AE impact amplitude and energy. It was shown that the effects of welding on the material mechanical properties can be well described with AE characteristics through contrastive analysis of two tensile samples,and the yield process of welding area can be reflected with the ＂twin peaks＂distribution of AE parameters on micro point. The test results provided reference data for application of AE technique in structural condition monitoring of cranes.