多裂纹扩展分析的边界元方法

采用边界元数值模拟和即时等效材料常数计算相结合的办法，只需模拟一个裂纹的扩展情况便可预测裂纹体的整体响应。针对准脆性材料的特点，采用粘性裂纹模型模拟裂纹开裂行为；采用二次裂纹扩展量作为增量控制变量，避免了软化及失稳分析中用力或位移作控制变量时遇到的困难。针对二交裂纹扩展路径未知情况，给出了预测和修正裂纹开裂界面的迭代技术，分析计算了含多个规则分布裂纹石膏板受压时的响应，并与实验结果进行了比较。结果表明该文方法的可行性与有效性。

BOUNDARY ELEMENT ANALYSIS OF CRACKED BODIES

A body containing many cracks is analyzed by boundary element method. To surmount the difficulty of tracing propagation of many cracks at the same time, a new procedure is proposed in which propagation of a representative crack around by homogenous effective materials is simulated by the sub-domain boundary element method. The influence of other cracks on the propagation of the representative crack is considered by changing material constants of the effective materials. To simulate the fracture process zone of rock-like materials, a cohesive crack model is used. With the wing crack's length as control variable, an incremental iteration algorithm is developed. Finally a cracked gypsum plate under compressive loads is computed. Fair agreements between the numerical and experimental results indicate the proposed procedure is feasible.