基于随机骨料模型的混凝土塑性损伤耦合力学性能研究

Study on the Concrete Plastic-Damage Coupled Mechanical Properties Based on Random Aggregate Model

为了探讨混凝土塑性损伤耦合力学性能,基于随机骨料模型和塑性损伤耦合模型,研究了骨料质量分数和加载速率对混凝土宏观力学性能的影响。通过几何模型及本构模型确定其参数,再利用数值模拟软件进行分析得出结论。研究结果表明:随着荷载增大,裂纹走向趋于复杂,局部裂纹扩展逐渐形成贯穿裂纹最终导致混凝土失效。骨料的存在改变了砂浆受力性能,骨料质量分数的增加提高了砂浆的强度,同时,高骨料质量分数也改变了混凝土的破坏模式。随着加载速率的减小,混凝土强度降低。

In order to explore the coupling mechanical properties of plastic damage of concrete,the effects of aggregate content and loading rate on the macroscopic mechanical properties of concrete were studied based on the random aggregate model and plastic damage coupling model.The Parameters are determined by geometric model and constitutive model,and then analyzed by numerical simulation software to draw a conclusion.The results show that:1)the crack orientation tends to be complicated as the loading increases.Local crack expansion gradually propagates eventually leading to concrete failure.The presence of aggregate changes the stressing properties of mortar.2)The increase of aggregate content increases the strength of mortar,on the other hand,high aggregate content a lso changes the damage mode of concrete.3)The strength of concrete decreases as the loading rate decreases.