Residual Stress Measurements in Front of a Crack Tip with High Spatial Resolution by Using Barkhausen Microscopy
Residual Stress Measurements in Front of a Crack Tip with High Spatial Resolution by Using Barkhausen Microscopy
复制标题
使用巴克豪森显微镜以高空间分辨率测量裂纹尖端前的残余应力
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Martin Krempe
中科院分区：
文献类型：
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作者：
I. Altpeter;G. Dobmann;N. Meyendorf;H. Blumenauer;D. Horn;Martin Krempe
当加载裂纹试样或构件时，在裂纹尖端的前面出现塑性区。如果卸载发生在裂纹扩展之前，一阶和高阶残余应力的建立会影响随后的裂纹扩展。具有实际重要性的是所谓的WP（温预应力）效应，其包括通过预应变来增加压力容器的耐脆性断裂性的可能性。因此，通过使用高分辨率的方法在裂纹尖端的塑性变形区中的局部残余应力状态的检测是理解断裂过程的重要前提，更广泛的目的是提高结构材料的损伤容限。尽管已经有一些关于X射线测量技术应用的报道，1-4到目前为止，关于利用微磁效应确定裂纹尖端区域局部残余应力状态的经验有限。本文的目的是验证确定裂纹尖端区域残余应力状态的方法基础。
Upon loading a cracked specimen or a component, a plastic zone emerges in front of the crack tip. If an unloading takes place before the crack growth, residual stresses of first and higher order build up which influence the subsequent crack growth upon reloading. Of practical importance is the so-called WP (warm-prestress) effect which includes the possibility of increasing the brittle-fracture resistance of a pressure vessel by pre-straining. The detection of the local residual stress state in the plastically deformed zone at the crack tip by using high-resolution methods is thus an important prerequisite for the understanding of the fracture processes with broader aim of improving the damage tolerance of structural materials. Whereas there have been several reports on the application of X-ray measurement techniques,1–4 up to now only limited experience is available concerning the using of micromagnetic effects for the determination of local residual stress states in crack tip region. It is the aim of this paper to verify the methodical basis for the determination of residual stress states in crack tip region.