论文部分内容阅读
采用有限元法分析了反平面剪切盒(I+III型)加载下岩石裂纹尖端的应力场,探讨了岩石发生反平面剪切(III型)断裂的机理。计算结果表明:在反平面压剪加载下,当压模角α为55 o～70 o,附加外压力能有效地抑制裂尖拉应力,使得裂尖最大剪应力与最大拉应力的比值τmax/σ1为3～6,τmax较易在σ1之前达到其临界值,从而发生反平面剪切(III型)断裂。反平面剪切盒实验是实现岩石III型断裂和测定岩石III型断裂韧度KIIIC的有效实验方法。
The finite element method was used to analyze the stress field of the rock crack tip under the anti-plane shear box (type I + III), and the mechanism of anti-plane shear (type III) fracture of the rock was discussed. The calculation results show that under the condition of anti-plane compressive shear stress, when the die angle α is 55 o ~ 70 o, the additional external pressure can effectively suppress the tensile stress at the crack tip so that the ratio of the maximum shear stress to the maximum tensile stress τ max / σ1 is 3 to 6, τmax is easier to reach its critical value before σ1, so that anti-plane shear (type III) fracture occurs. The anti-plane shear box experiment is an effective experimental method for achieving rock type III fracture and for measuring rock type III fracture toughness KIIIC.