【摘要】 本文运用线弹性断裂力学的理论 ,采用有限元数值计算的方法 ,对混凝土中粗骨料含有原始内裂纹的个体 ,在压剪应力场作用下发生裂纹失稳扩展的条件进行了研究。利用测取的粗骨料材料 型裂纹的断裂韧度 K C,判定压剪应力场中粗骨料的裂纹体是否开裂使混凝土产生破坏机理。本文给出了相同外荷载和相同裂纹长度时最危险的裂纹方向 ,以及粗骨料裂纹体造成混凝土抗压强度降低的条件更多还原

【Abstract】 Based on the theory of linear elastic fracture mechanics and finite element numerical method,the condition of crack propagating in compressionshear stress field is studied about the aggergate in which the initial internal microcrack exists Whether the microcrack in aggregate will propagate to cause the concrete to failure is determined by using the experimentally obtained Mode-Ⅱ fracture toughness KK ⅡC of the aggregate material When the external loads are equal and the lengths of microcracks are the same the most dangerous orientation of the microcrack is given in the paper The condition under which the microcrack of aggregate causes the decrease of the compressive strength of concrete is also given更多还原