【作者】 黄小平； 崔维成； 冷建兴；

【Author】 HUANG Xiao-ping~1, CUI Wei-cheng~2, LENG Jian-xin~2 (1. School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200030, China; 2. China Ship Scientific Research Center, Wuxi 214082, China)

【机构】 上海交通大学船舶海洋与建筑工程学院； 中国船舶科学研究中心；

【摘要】 许多工程结构在服役过程中受到随机载荷的作用,载荷循环之间的相互作用对裂纹扩展将产生明显的影响。变化载荷作用下裂纹扩展律和疲劳寿命的计算对工程结构的寿命的可靠预测是十分重要的。提出了一个由应力比和裂纹尖端约束及塑性区尺寸为主要参数的随机载荷作用下裂纹扩展率计算模型。用该模型对几种谱载荷作用下7075—T6和2024—T3铝合金试件的疲劳扩展试验结果进行了预测,预测结果和状态空间模型以及著名的疲劳计算程序FASTRN和AFGROW的预测结果进行了比较,结果表明本模型能给出较好的预测精度。更多还原

【Abstract】 Many engineering structures are subjected to random loading in service. The load cycle interactions can have a very significant effect in fatigue crack growth under variable amplitude loading. Study of fatigue crack growth rate and fatigue life calculation under random loading is very important for the reliable life prediction of engineering structures. In this paper, a fatigue life prediction model under various load spectra, taking the stress ratio and the plastic zone size near crack tip as main parameters in calculating the crack opening ratio, has been proposed. The present model is validated with fatigue crack growth test data provided by Ray under various variable amplitude and spectrum loading in 7075-T6 and 2024-T3 aluminium alloys, respectively. Predictions of present model are compared with those of the state-space model. FASTRN and AFGROW codes. The results show that the predicted results are in good agreement with the test data.更多还原