Study on initiation and propagation of a single closed crack under compression-shear stress
Field equation of single and closed flaw tip under compression-shear stress is constructed in this paper.The initiation angle of wing crack,the influence of side pressure coefficient k on stress field and ini-tiation and propagation of wing crack and the influence of flaw angle α on initiation stress of wing crack under uniaxial compression are analyzed by using the maximum tangential stress criterion.The correctness of the theoretical solution is verified by uniaxial compression test and triaxial compression literature data comparison.The research shows that the effect of T-stress on the initiation angle of wing crack can be ig-nored when the critical relative size of cracking A approaches 0 or the flaw angle α approaches 45°.Hoop tensile stress decreases with the increase of side pressure coefficient k,and axial stress required for the ini-tiation of wing crack increases.The confining pressure has an inhibitory effect on the propagation of wing cracks and the inhibitory effect is stronger when effective shear stress of the flaw surface is greater than 0.Wing cracks and a small number of anti-wing cracks and coplanar shear cracks are observed at the tip of the pre-existing flaw.The initiation angle of wing cracks are fluctuated around the predicted value.The ini-tiation stress of wing crack increases with the increase of flaw angle under uniaxial compression,and it also increases with the increase of side pressure coeffiicient under triaxial compression,and they are consistent with the changing relationship predicted by the model in this paper.
T-stresseffective shear stresswing crackside pressure coefficienthoop stressuniaxial compression test
万方数据
维普
