【摘要】 从细观结构出发,把混凝土看作由骨料、界面和砂浆组成的非均质复合材料,建立随机骨料模型,应用损伤塑性本构,对试件进行了冲击荷载作用下的数值模拟,通过施加不同的加载方式,研究材料的损伤破坏过程,最终以位移加载得出荷载-位移曲线的峰值强度作为细观混凝土试样的破坏强度。通过对混凝土进行冲击荷载作用下的实时CT扫描,得出试件的荷载位移曲线及各个应力阶段的CT图像,发现数值模拟所得混凝土强度及破坏过程与CT观测到的结果有较好的相似性。结果表明,利用该方法研究混凝土在冲击荷载作用下的损伤破坏过程是合适的,以荷载-位移曲线的峰值点作为混凝土破坏强度点是合理的。更多还原

【Abstract】 Concrete was taken as three-phase composites consisting of aggregate,bond and mortar on micro-level.We established the random aggregating model and applied the concrete damage plasticity model.By applying different loading we carried out the numerical simulation of the specimen under impact load.Eventually,the peak intensity obtained from the load-displacement was regarded as the destruction strength of the micro-concrete specimens.We researched the material damage process and gained the CT image of each stress stage by the scanning of the specimen under impact loading.We found the failure process and the destruction strength of the numerical simulation is similar to the CT test.The results show that the method is convenient to simulate the damage and fracture of concrete under impact loading.Taking the peak intensity of the load-displacement curve as the destruction strength is reasonable.更多还原