摘要
研究了含裂纹板在低速率冲击载荷作用下的互型动态起裂问题。分析了裂尖塑性区附近的周向应变，利用裂尖塑性流变模型的概念，建立了一个裂尖计算模型，推导出裂尖张开位移和裂尖塑性区周线上最大周向应变的关系。据此提出最大周向应变理论作为动态起裂准则。通过ＬＹ１２ＣＺ制成的带裂纹试件在ＭＴＳ─８１０试验机上进行冲击拉伸试验，利用数值计算和实验结合的方法，计算了εθ·（ｔ）、ＣＴＯＤ（ｔ）和Ｊｄ（ｔ）随时间的变化曲线，验证了最大周向应变理论作为动态起裂准则的可行性。
The problem of dynamic initiation for crack-containing plate of I-mode under low-velocity impact load is investigated in this paper. The tangential strain of crack tip plastic zone is analysed and a calculation model of crack tip is set up by using the pattern of crack tip plastic flow. Then a relationship is established between CTOD and maximum tangential strain on the circumference of the crack tip plastic zone. According to the analySis, a dynamic initiation fracture criterion- maximum tangential strain theory is put forward.In this paper, the impact tensile tests of the crack-containing LY-12CZ specimen are carried out on the MTS- 810 machine. Using numerical computation- experimental method,the curves relating εθ0.(t), CTOD(t) and Jd (t) to time t are calculated. Thereby the effectiveness of the maximum tangential strain theory as dynamic initiation criterion is proved.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1996年第2期217-223,共7页
Journal of Northwestern Polytechnical University
基金
航空科学基金
关键词
失效准则
裂纹
板
冲击载荷
断裂力学
dynamic initiation, maximum tangential strain, failure criterion, dynamic J integral
