纤维混凝土力学性能分析的随机双尺度模型

A Stochastic Two scale Model for Mechanical Properties Analysis of Fiber Reinforced Concrete

摘要:

短纤维增强混凝土作为一种复合材料，其力学性能不但与基体的性能有关，还与材料的细观特征有关.为了将细观结构与宏观力学性能相结合，以双尺度方法为理论基础，根据短纤维增强混凝土的材料特点通过引入随机参数，在单胞中生成满足均匀分布概率模型的圆柱体来模拟乱向随机分布的短纤维，进而定义了一种新的单胞模型，建立了随机双尺度模型，并结合有限元方法进行计算；接着将随机双尺度模型与试验以及其他经典方法进行对比，验证了其在分析短纤维增强混凝土力学性能方面的有效性；最后利用此模型研究分析了纤维种类和体积分数对短纤维增强混凝土弹性常数的影响.

Abstract:

Short fiber reinforced concrete (Short FRC) is a kind of composite material with fiber distributed randomly and intricately. Its mechanical properties are based on not only the performance of the concrete matrix, but also its micro constitution. To combine the micro constitution with macroscopic mechanical analysis, a stochastic two scale model for mechanics parameters computation of Short FRC is presented. First, a new model for representative element volume (REV) is further described with some random parameters based on the practical configuration. Then, finite element method FEM model of each REV sample with the same probability distribution is established to calculate. A comparative study is conducted of the experimental results and the results by other classical methods, which demonstrates the presented model is a significant precise way to estimate the elastic constants of Short FRC. Finally, the influences of fiber’s type and volume fraction on the elastic constants of Short FRC are investigated.