数字化分布钢纤维增强水泥基复合材料方凳数值模拟研究

Numerical Simulation of Cementitious Composites Stool with Digitally Distributed Steel Fibers

掺入钢纤维可以改善水泥基复合材料的抗拉性能及韧性,通过主拉应力分布设计钢纤维方向及掺量,实现钢纤维数字化分布,能充分发挥钢纤维在基体中的增强作用。本文以方凳为研究对象,通过数值模拟建立了拉应力大小、方向和钢纤维分布的关系,确定了方凳中钢纤维的数字化分布,并进行了方凳控制截面受力性能分析。在方凳面板跨中截面处,数字化分布钢纤维分布数量分别比定向、随机分布钢纤维提高了187%、514%,钢纤维合力分别提高了276%、888%;在侧板上端正截面处,数字化分布钢纤维分布数量分别比定向、随机分布钢纤维提高了113%、355%,钢纤维合力分别提高了218%、775%。结果表明,与定向、随机分布钢纤维相比,数字化分布钢纤维增强作用明显提高,方凳面板跨中截面及侧板上端正截面处的钢纤维数量更多,钢纤维合力更高。

The addition of steel fibers into cementitious composites can improve the tensile performance and toughness.The direction and volume fraction of steel fibers are designed according to the distribution of tensile stress,which is defined as digitally distributed steel fiber,and can maximize the reinforcement of steel fibers on cementitious composites.In this paper,a stool was chosen as case study.The relationship between the magnitude and direction of tensile stress with the distribution of steel fibers was established by numerical simulation,and the digitally distributed steel fibers in the stool were determined.The mechanical properties of critical cross-sections of the stool were analyzed.In the midspan of the top slab of the stool,the amount of digitally distributed steel fibers is 187%and 514%higher than that of aligned and randomly distributed steel fibers,and the resultant force undertaken by the digitally distributed steel fibers increases by 276%and 888%,respectively,compared to that by aligned and randomly distributed steel fibers.The amount of digitally distributed steel fibers is 113%and 355%higher than that of aligned and randomly distributed steel fibers in the top normal section of side slab of the stool,and the resultant force undertaken by the digitally distributed steel fibers increases by 218%and 775%,respectively,relative to that by aligned and randomly distributed steel fibers.The results show that the reinforcement effect of digitally distributed steel fibers is significantly improved compared with aligned and randomly distributed steel fibers,and the midspan cross-section of the top slab and the top normal section of side slab are characterized by an increasing number of steel fibers,which leads to a higher steel fiber resultant force.