基于纤维混凝土单轴压缩试验的离散元模拟

Discrete Element Simulation Based on Fiber Concrete Uniaxial Compression Test

模拟了纤维混凝土试样单轴压缩破坏过程,分析了纤维混凝土中细观参数、纤维长度和直径对其力学特性的影响。研究结果表明:纤维混凝土试样在内部最先出现裂隙,随着加载的进行,裂隙数量经历缓慢增加到急速增加再缓慢增加的过程;且随着摩擦系数的增加,纤维混凝土试样的单轴抗压强度提高;随着孔隙率的增大,纤维混凝土的弹性模量减小,抗压强度先增大后减小;随着纤维长度的增加,纤维混凝土试样的弹性模量变化不大,抗压强度先增大后减小;随着纤维直径的增大,试样抗压强度减小,且峰值抗压强度对应纤维直径为0.2 mm。

In this paper,the failure process of fiber reinforced concrete specimens under uniaxial compression is simulated,and the effects of microscopic parameters,fiber length and diameter on mechanical properties of fiber reinforced concrete are analyzed.The results show that cracks appear firstly in the fiber reinforced concrete sample,and the number of cracks increases slowly,rapidly and then slowly with the loading process.With the increase of friction coefficient,the uniaxial compressive strength of fiber reinforced concrete specimens increases.With the increase of porosity,the elastic modulus of fiber reinforced concrete decreases,and the compressive strength increases first and then decreases.With the increase of fiber length,the elastic modulus of fiber concrete specimens has little change,and the compressive strength increases first and then decreases.The compressive strength decreases with the increase of fiber diameter,and the peak compressive strength corresponds to the fiber diameter of 0.2 mm.