Crack-Tip Stress Field Measured by Infrared Thermography and Fracture Strength in Bonded Dissimilar Plate.
Crack-Tip Stress Field Measured by Infrared Thermography and Fracture Strength in Bonded Dissimilar Plate.
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通过红外热成像测量粘合异种板的裂纹尖端应力场和断裂强度。
DOI：
10.2207/qjjws.18.487
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
T. Izuma
中科院分区：
文献类型：
--
作者：
I. Oda;Yuichi Tanaka;A. Masuki;T. Izuma
以铜-低碳钢复合爆炸复合板为例进行了研究。拉伸试验使用从复合板中提取的矩形板试样进行。在每个试样中制造人工贯穿厚度的边缘裂纹或平行裂纹。裂纹密集且垂直于爆炸界面。通过实验和弹塑性有限元分析，研究了在垂直于裂纹面方向施加拉伸载荷时，裂纹附近的应力场、应力强度因子、裂纹张开位移和断裂强度。利用红外应力成像系统对应力场和应力强度因子进行了测量。揭示了材料的非均匀性、残余应力、材料特性的变化以及平行裂纹的相互作用对应力场、应力强度因子、变形行为和断裂强度的影响。粘结界面前的低强度材料使应力强度因子和裂纹张开位移增大。粘结界面前的高强度材料降低了应力强度因子和裂纹张开位移。材料的不均匀性和平行裂纹的相互作用对裂纹张开位移的影响可以用低应力水平下应力强度因子的平方来解释。非均匀试样的脆性断裂强度可以由应力强度因子和线弹性断裂力学准则来评价。
An explosion clad plate composed of copper and mild steel is dealt with as a typical example of the bonded dissimilar plate. Tensile tests are carried out using rectangular plate specimens extracted from the clad plate. An artificial through-the-thickness edge crack or parallel cracks are made in each specimen. The cracks are close and perpendicular to the explosive interface. When a tensile load is applied perpendicularly to the crack plane, stress field near cracks, stress intensity factor, crack opening displacement and fracture strength are examined by experiment as well as elasto-plastic finite element analysis. The stress field and the stress intensity factor are evaluated by an infrared stress imaging system. The effects of the material inhomogeneity, the residual stress, the change of material characteristics and the interaction of parallel cracks on the stress field, the stress intensity factor, the deformation behavior and the fracture strength are revealed. The lower strength material ahead of the bonded interface increases the stress intensity factor and the crack opening displacement. The higher strength material ahead of the bonded interface decreases the stress intensity factor and the crack opening displacement. The effects of the material inhomogeneity and the interaction of parallel cracks on the crack opening displacement can be explained from the square of stress intensity factor at the low applied stress level. The brittle fracture strength of the inhomogeneous specimen can be evaluated from the stress intensity factor and linear elastic fracture mechanics criterion.