【摘要】 进行了三种开裂模式无钉载平板的广布损伤裂纹扩展试验,研究发现裂纹间的干涉作用明显促进了裂纹的扩展,多裂纹情况下的裂纹扩展速率远大于单裂纹。同时,利用FRANC2D/L计算和分析了单裂纹、多孔相邻裂纹、多孔不相邻裂纹和多孔等长裂纹等四种开裂模式的裂纹扩展行为及应力强度因子分布。结果表明,裂纹扩展初始阶段主要受孔自身应力集中影响,裂纹间的干涉作用弱;随着裂纹扩展到一定长度时,裂纹间的干涉作用显著增大,且随着裂纹间韧带长度的减小而快速增加,与试验结果一致。更多还原

【Abstract】 Panels with three kinds of cracking model were tested under cyclic loads to study the propagation of multiple cracks.The results showed that crack interaction could speed up the expansion of cracks significantly and the crack growth rate of multiple cracks was much faster than that of single crack.Four finite element cracking models,including single crack,adjacent cracks of multiple holes,non-adjacent cracks of multiple holes,equal-length cracks of multiple holes,were built by FRANC2D/L to study the growth behaviour of multiple cracks and the distribution of stress intensity factors.The numerical simulation results indicate that at the initial stage of crack growth,cracks are mainly influenced by the stress concentration of holes and the interference effects between cracks are weak.When cracks extended to certain length,the interference effects between cracks enlarged obviously and the effects increased rapidly as ligament lengths decreased,which are in agreement with the test results.更多还原