Measurement of mode II threshold stress intensity factor range ΔKIIth
Measurement of mode II threshold stress intensity factor range ΔKIIth
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II型阈值应力强度因子范围ΔKIIth的测量
DOI：
10.2472/jsms.51.918
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
S. Hamada
中科院分区：
文献类型：
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作者：
Y. Murakami;Taketo Fukuhara;S. Hamada
为了测量不同材料的II型疲劳裂纹扩展抗力，设计了一种特殊的带侧槽的人字形缺口双悬臂型试件。用新设计的试件进行的II型疲劳裂纹扩展试验是在常规的闭环式拉压疲劳试验机上进行的，加载幅值恒定，相当于随着裂纹长度的增加而进行的ΔKii递减试验。用交流电位法测量了裂纹长度。研究了II型裂纹断口的特殊形貌。利用有限元软件ABAQUS分析了裂纹尖端的剪应力分布和II型应力强度因子。得到了不同材料的II型裂纹扩展速率(da/dN)与ΔK_(II)的关系，并确定了ΔK_(II)值。结果发现，在本研究所测试的所有材料中，ΔKIIth大于ΔKith。
In order to measure the Mode II fatigue crack growth resistance of various materials, a particular chevron notched double-cantilever type specimen with side grooves was designed. Mode II fatigue crack growth tests by using the newly designed specimens were conducted by a conventional closed-loop type tension-compression fatigue testing machine under a constant load amplitude which corresponds to the ΔKII-decreasing test with increase in crack length. The crack length was measured by the AC potential method. The particular morphology of Mode II crack fracture surface was investigated. The distribution of shear stress in crack tip and Mode II stress intensity factor were analyzed using a FEM software, ABAQUS. The relationships between Mode II crack growth rate (da/dN) and ΔKII for various materials were obtained, and the values of ΔKIIth were determined. It was found that ΔKIIth is larger than ΔKIth for all materials tested in this study.