【作者】 刘小妹； 卞永明； 梁拥成；

【Author】 Liu Xiaomei;Bian Yongming;Liang Yongcheng;College of Mechanical Engineering, Shanghai University of Engineering Science;College of Science, Donghua University;School of Mechanical Engineering, Tongji University;

【机构】 上海工程技术大学机械工程学院； 同济大学机械与能源工程学院； 东华大学理学院；

【摘要】 有限断裂准则为双重参数脆断准则,假设裂纹或切口端部有限裂纹增长,当应力和能量同时达到临界值,发生断裂。基于U形切口两种形式有限断裂准则,对文献中的铝合金U形切口三点弯曲断裂实验进行了分析验证。一方面基于材料的断裂韧度和抗拉强度,预测切口件断裂载荷;另一方面根据几组不同的切口根部半径及其对应的临界切口应力强度因子,估算材料的断裂参数。对两种不同形式有限断裂准则预测结果与平均周向应力准则、最大周向应力准则以及实验结果进行了比较,得出,无论是预测断裂载荷还是估算材料断裂参数,线方式有限断裂准则,与实验结果比较吻合,尤其是估算的断裂韧度精度较高。更多还原

【Abstract】 The governing idea of Finite Fracture Mechanics a coupled fracture criterion, is that at failure a finite increm ental crack(or a finite advance) occurs at the notch tip. The stress and energy conditions must be fulfilled simultaneously, constituting a sufficient criterion for crack initiation. Based on two different editions of finite fracture mechanics, the three pointing bending experiments of alloy Al were analyzed in the literature. On one hand, the values of fracture loading can be predicted according to the fracture toughness and tensile strength of the material. On the other hand, the fracture toughness and tensile strength can be calculated by several groups of notch root radius and critical notch stress intens ity factor. The results from finite fracture mechanics were compared with those according to mean circum ferential stress criterion, the maximum circumferential stress criterion and the data in the literatue.The FFM-LM is better at predicting fracture loading and calculating the fracture param eters as well,especially at calculating the fracture toughness.更多还原