利用有限元方法模拟力学拉伸试验以钢纤维混凝土为例

力学试验是获取岩石等许多工程材料力学性能的主要方法之一。 但是对某些特殊材料, 由于影响其力学性能的因素众多, 单纯通过试验来获取其力学性能, 成本高, 过程复杂。 如工程抗震中目前普遍使用的钢纤维混凝土(SFRC), 很难单纯通过力学试验来获取钢纤维的分布对其力学性能的影响。 本文基于随机方法对钢纤维混凝土建立有限元模型, 利用数值模拟的方法来估计钢纤维的分布和体积率对钢纤维混凝土拉伸性能的影响。 通过与试验结果比较验证了其可行性, 结果表明钢纤维的分布对钢纤维混凝土屈服前的力学性能影响较小, 对屈服后的应力-应变特征影响较大。 当钢纤维体积率从1%变化到2%, 钢纤维混凝土的屈服强度与体积率大致为线性关系, 强度随之增加。

Simulation of Tensile Test of the Steel Fiber Reinforced Concrete with the Finite Element Method

Mechanical test is one of the main methods to obtain the mechanical properties of rocks and many engineering materials. Given many factors that affect the mechanical properties of some special materials, it is hard to get their mechanical properties only through the test because of high cost and complex process. Steel fiber reinforced concrete (SFRC) as a structural material has been used widely in many major constructions because of its good mechanical performance. However, it is difficult to evaluate the effect of steel fiber distribution on SFRC mechanical behavior with experiment. This paper constructed a model based on randomized method and solved the equation by finite element method, which was called randomized finite element method (RFEM). The results show that the steel fiber distribution has little influence on the pre-yield behavior of SFRC, but has a major impact on the post-yield response. From a change of 1% to 2%, the volume fraction of steel fibers and tensile yield strength of SFRC represents approximately a linear relationship.