弯曲荷载诱发微型梁开裂演化过程的可视分析

Visual analysis for cracking evolution of micro-beam under three-point bending

传统的三点弯曲试验无法对试样内部裂缝进行可视量化分析.为了直观地观察三点弯曲下试样开裂演化过程,采用X射线微观层析成像(X-ray microcomputed tomography,X-ray μCT)技术对三点弯曲荷载作用下微型梁的开裂过程进行原位追踪监测,基于试样的二维/三维的形貌特征图对孔隙和裂缝进行可视量化分析.结果表明,X-ray μCT测试技术是一种有效的非破坏性的原位跟踪方法,可以获得试样内部孔隙与裂缝三维可视化图,获取三点弯曲试验的试样裂缝扩展全过程,并可进一步对试样的裂缝与孔隙进行定量分析,获得X-ray μCT测试裂缝长度变化曲线与裂缝体积柱状图.研究表明,裂缝长度与体积随加载呈上升趋势.

The traditional three-point bending test is unable to realize visual quantitative analysis of sample internal crack.In order to observe the crack evolution process,we,in-situ,track and monitor the micro-beam cracking process under the three-point bending by X-ray microcomputed tomography technology(X-rayμCT).We analyze quantitatively the pore and crack of micro-beam by 2D/3D visualization of the morpholog characteristics.The results show that X-rayμCT technology test is an effective nondestructive and in-situ tracking method;The three-dimensional visualization of pore and crack and the crack propagation under three-point bending test can be obtained;moreover,crack and pore quantitative analysis can be performed to get the length variation curve of crack under X-rayμCT test and the crack volume histogram.