T应力对线弹性材料脆性断裂的影响
Effect of T-Stress on the Brittle Fracture for Linear Elastic Materials

在考虑裂纹尖端应力场常数项T应力的基础上对传统的最小应变能密度因子准则(minimum strain energy density criterion,SED)进行修正,应用修正的最小应变能因子准则对Ⅰ型、Ⅱ型和Ⅰ-Ⅱ复合型脆性断裂问题分别进行研究,分析T应力对裂纹扩展方向和断裂时刻应力强度因子的影响并给出不同T应力条件下的通用的Ⅰ型、Ⅱ型和Ⅰ-Ⅱ复合型裂纹扩展条件,并将预测结果与现有的试验数据进行比较。分析表明,T应力对于Ⅰ型、Ⅱ型和Ⅰ-Ⅱ复合型断裂均有显著影响,考虑T应力的SED预测结果和试验结果吻合很好。
The conventional minimum strain energy density (SED) criterion is modified by taking into account the effect of nonsingular stress term (T-stress) in addition to the singular stress term. Then we use the modified SED criterion to study the effect of T-stress on the fracture initiation angle and the critical intensity factors of brittle materials under mode Ⅰ, mode Ⅱ and mixed Ⅰ-Ⅱ mook loading conditions. The general conditions for forecasting mode Ⅰ, mode Ⅱ and mixed Ⅰ-Ⅱ mode fracture under various T-stress are provided. The forecast results are compared with some earlier experimental results. The analysis shows that the presence of T-stress has a significant effect on mode Ⅰ, mode Ⅱ and Ⅰ-Ⅱ mixed mode fracture in brittle fracture of linear elastic materials; there is a good agreement between experimental results and results forecast with the modified SED criterion