复合型裂纹的混合开裂准则

利用两个基本假设：１裂纹启裂方向为裂尖距其近旁等应变能密度线最近的方向;２当裂尖近旁材料的有效应力达到Ｉ型裂纹的临界拉应力时即发生启裂;由此给出了复合型裂纹的应力和能量混合型断裂判据。对临界断裂,准则还计入了尖端损伤区的影响。与实验结果对比证明了混合型断裂准则的有效性。

A Mixed Fracture Criterion for Mixed Mode Crack Propagation

This paper presented a mixed fracture criterion for mixed mode crack problems. Based on two assumptions, that is the crack propagates in the direction of the nearest distance from the initial crack-tip to the isostrain-energy-density curve around the tip, and when the effective stress in the direction tends to the threshold tensile stress of pure mode I crack, the mixedmode crack will propagate. The mixed criterion discussed the "dxed mode crack problem both from stress mechanism and energy mechanism account for the change of mechanical properties in the near tip damage regions. The comparison of the resultS of the criterion and the experimentation verified the validity of the criterion.