应变硬化水泥基复合材料构件剪切破坏评价方法研究

Evaluation method on shear failure behavior of strain-hardening cementitious composite member

依据应变硬化水泥基复合材料构件剪切破坏时断裂表面特性,提出适合该类材料构件剪切破坏的格子等价连续体评价方法。首先对应变硬化水泥基复合材料构件剪切破坏时裂缝表面的凹凸程度进行定量量测,在此基础上,提出适合描述该类材料裂缝形态的参数,形成描述应变硬化水泥基复合材料构件裂缝面形态的假设裂缝,并提出相应的剪切格子体系。此后,改进了日本名古屋大学提出的用于评价混凝土及钢筋混凝土构件剪切破坏的格子等价连续体方法,使得改进的格子等价连续体方法适用于应变硬化水泥基复合材料构件剪切破坏。该方法考虑了裂缝面压缩侧接触及拉伸侧纤维架桥应力对裂缝面剪应力转移的影响,形成适用于应变硬化水泥基复合材料构件剪切破坏的裂缝面剪应力转移模型。

Based on the fracture surface properties of strain-hardening cementitious composite member at shear failure, a lattice equivalent continuum model suitable for this material member was proposed. Firstly, the crack surface roughness of strain-hardening cementitious composite member at shear failure was measured, and then the appropriate parameters for this material＇ s crack shape were proposed for describing the crack shape of the assumed crack in strain-hardening cementitious composite member, and furthermore the corresponding shear lattice system was presented. Thereafter, the lattice equivalent continuum model （developed for concrete and RC concrete member at shear failure by Nagoya University） was improved to suit for the shear failure of strain-hardening cementitious composite member. The effects of the contact stress in compression part and fiber bridging stress in tension part on shear stress transfer behavior of crack surface were considered in the improved method, and hence the shear stress transfer model for crack surface of strain- hardening cementitious composite member was derived.