NUMERICAL ANALYSIS OF SHORT FIBER REINFORCED CEMENT-BASED COMPOSITES IN DIRECT TENSION
短纤维水泥基复合材料的拉伸数值分析

soft region was defined as a local region including microcrack,microdefect,etc.based on mesoscopic mechanics method;and it was assumed that mortar specimen was composed of mortar matrix and many soft regions are distributed in the matrix.In terms of Monte Carlo random sampling principle,it could be acquired that soft region elements are randomly distributed in the matrix.Material heterogeneity of matrix elements and soft region elements were depicted with Weibull parameters,and matrix elements and soft region elements were in accordance with low tension crack law,thus mortar tension numerical model can be built.Considering effects of distribution of soft regions,Weibull distribution parameters,mesoscopic element mechanical parameters on numerical experiments,the mechanical behaviors of mortar tension crack are analyzed.Based on mortar tension numerical model,short fiber reinforced mortar numerical model that was treated as three-phase composites including matrix,soft region and short fiber,was also built.With the numerical model,tension crack behavior of short fiber reinforced mortar was researched;the effects of fiber mesoscopic mechanical parameters such as fiber length,fiber diameter,fiber distribution characters on numerical tension results were also analyzed.Finally,numerical results were compared with experimental data,and the results display that numerical model can successfully simulate mortar tension crack and strengthening character of short fibers with mortar.The complete curve of mortar tension stress-strain agrees well with experimental results.