【作者】 李显方；

【Author】 X.-F.Li;School of Civil Engineering,Central South Universtiy;

【机构】 中南大学土木工程学院；

【摘要】 受压荷载作用下的含缺陷介质有着广泛的应用,如地质结构中的断层受到围压及板块运动的挤压等。尽管拉伸介质中的裂纹问题已经有极为丰富的研究成果,但许多结论并不能直接推广到受压剪作用介质中的裂纹问题。在对于压缩荷载作用下介质中的裂纹问题,我们分解问题受到压应力和剪应力作用,研究了裂纹尖端的应力场变化规律。1)研究并讨论了压剪裂纹的裂尖奇异性的不同,压剪介质内的裂尖奇异性仅仅依赖于剪应力,压缩应力只能引起裂纹方向及垂直于裂纹方向的两个方向T应力,但并不产生应力奇异性,而拉伸介质内的裂尖应力奇异性既依赖于正应力又依赖于剪应力;2)分析了压应力及裂纹面上摩擦力对裂尖小范围塑性屈服区、Mises等效应力及裂纹偏折角的影响;3)对于两个不同介质的界面裂纹,通过积分变换方法求解相应的混合边值问题,与传统的拉伸介质内的界面裂纹的结论不同,裂尖奇异性仅仅表现为平方根奇异性,而不是振荡奇异性。这些结果的应用较好的解释了实验室及野外地质现象中观察到的裂纹偏折现象。更多还原

【Abstract】 Media with defects subject to compressive and shear loadings are widely used such as faults subject to confining pressure of ambient structure. Although great progress on crack problems of tensile loading has been made, many conclusions cannot directly extended to cracked media under compression along with shear. For cracks subject compression and shear, crack-tip field is studied. 1. Singularity of crack-tip field is focused, which depends on shear loading, and compressive loading causes two T-stresses,which are parallel to and perpendicular to the crack, respectively; 2. The influence of compressive stress and frictional stress on the small-scale yield zone around the crack tip, Mises effective stress, and kinking angle is analyzed; 3. For an interface crack of a bi-material, a mixed boundary value problem is solved using integral transform and the usual oscillatory singularity does not appear. Only usual square-root singularity occurs. Field observations of structural geology and experimental data are well explained.更多还原