预静载对细观混凝土动态力学特性的数值试验研究

Numerical Experiment of the Dynamic Mechanical Properties of Meso Concrete Under Static Pre-loading

预静载对混凝土的动压强度和动弯拉强度的影响完全不同。为了研究动压荷载作用下预静载对混凝土动态力学特性的影响,从数值试验出发,根据自行编制的混凝土随机骨料有限元模型,应用塑性损伤本构,不同的应变率下施加不同的初始预静载大小,分析动压荷载作用下,预静载对混凝土动压强度和破坏形态的影响。结果发现:不同的应变率下,预静载对混凝土动压强度的变化程度不同,但都会导致混凝土动压强度降低;预静载水平大小不同,混凝土的破坏形态也不尽相同。

The influence of the dynamic compressive strength and the dynamic bending strength is completely different under the static pre loading.To study the dynamic mechanical property of concrete under static pre-loading,numerical experiment was adopted and a programme was developed by the authors which is a stochastic aggregate finite element model for concrete.According to the plastic damage constitutive,by applying different static pre-loading under the different strain rates,the strength and failure modes of concrete affected by the static pre-loading was analyzed.The results showed that the static pre-loading have different influences on the dynamic compressive strength of concrete under different strain rates,and they all will reduce the dynamic strength.The concrete failure mode is not the same under the different static pre-loading sizes.