拉/扭复合载荷下氧化铝的切口强度及预测

提出了适用于陶瓷切口件拉／扭复合应力下的断裂准则，其中不合经验参数。采用具有不同应力集中系数的Al2O3陶瓷管状试样，在不同的拉／扭复合应力状态下测定了断裂强度。试验结果证明了该断裂准则的有效性和通用性。利用现有文献中的相关试验结果，对上述断裂准则作了进一步的客观校核。根据该断裂准则和陶瓷材料拉伸强度的概率分布参数，还可预测陶瓷材料光滑试样和切口件在拉／扭复合应力下具有存活率的断裂准则。提出的断裂准则具有工程应用意义。

Notch Strength and Prediction of Al2O3 Ceramic under Combined Tension/Torsion Loading

In the present study, a fracture criterion for ceramics under combined tension/torsion loading is proposed, which does not contain any empirical constants. The fracture strength of Al 2O 3 tubes under combined tension/torsion loading was measured by using test specimens with different stress concentration factors. Test results show that the above criterion is available and generally applicable for both smooth- and notched elements of ceramics. Some existing test results in literature are also used to objectively check the above criterion. Moreover, the fracture criteria of ceramics with given survivability under combined tension/torsion can be predicted from the above fracture criterion and the probability distribution parameters of tensile strength of ceramics. It may be thought that the fracture criterion for ceramics under combined tension/torsion loading proposed in this study is of practical significance in engineering.