关键词: 水泥基复合材料;断裂;粘聚裂纹;细观;尺寸效应

Abstract: The finite element model of steel fiber reinforced cementitious composites was established based on random generation algorithm,simulated whole process of bend fracture for a three-point bend Aligned Steel Fiber Reinforced Cementitious Composites(ASFRC)beam using cohesive crack model.The reliability of the numerical model was verified by comparing load-deflection curve of numerical simulation and existing experimental results.The effects of different cohesive-law of matrix on the whole fracture process for ASFRC were investigated.And the whole fracture process of specimens with different sizes was simulated and analyzed.The influence of specimen's size on the fracture behavior of ASFRC was studied.The results show that in this study,simulated results of finite element model for ASFRC matched well with experimental results, the types of cohesive-law have little influence on the fracture complete curves;with the increase of specimen's size,the nominal strength of ASFRC has a obvious size effect, the meso-scale numerical model can effectively study the meso-scale failure mechanism.

Key words: cementitious composites;fracture;cohesive crack;meso-scale;size effect