多轴应力状态下脆性材料统计断裂判据的研究

Study on Criterion of Statistical fracture for Brittle Materials under Multiaxial Stress State

应用统计断裂理论,用分币裂纹模型模拟材料中的缺陷,通过用裂纹面的法向矢量反映材料中裂纹面的随机取向,用等效应力代替实际应力状态的破坏效应,提出了多轴应力状态下脆性材料统计断裂的判据。判据反映了结构的破坏强度与其所受的应力状态、破坏概率及材料的性能参数之间的联系关系。通过判据可得出对当前研究成果的一些合理解释,最后用判据的预测与实验数据进行比较,结果较吻合。

By means of selecting penny-shaped crack model to simulate the defects in material,using the normal vector of the crack＇s plan to reflect the random direction of the crack＇s plan in the material and using effective stress to replace the stress state,the criterion of statistical fracture for brittle materials under multiaxial stress state is developed.The criterion reflects the relation of the strength of construction,the stress state,failure probability and the material＇s coefficients.Some reasonable explanations for research results by now can be got from this criterion.The forecast by this criterion is in a good accordance with the test data.