【摘要】 饱和混凝土中孔隙自由水的存在对材料的力学性能有显著的影响,动态工况中主要表现为自由水的粘性效应,且该效应随细观损伤引起的微裂纹密度的改变而变化。本文结合太沙基"有效应力原理",建立了饱和混凝土考虑动态应变率效应的单轴拉伸统计损伤模型,将材料宏观力学性能同细观损伤机理有机地结合起来,综合考虑了动态条件下惯性效应和自由水粘性效应的影响,认为材料自身的惯性效应引起材料破坏形态以及细观损伤演化过程的改变;水的粘性效应则调整了混凝土基体的受力状态。通过算例和试验结果比较,表明该模型可预测等应变率加载情况下饱和混凝土材料均匀损伤阶段的动态拉伸本构行为,形象地描述了饱和混凝土材料动态损伤演化机制。更多还原

【Abstract】 The existence of pore water in the saturated concrete has the remarkable influence on the mechanical property of concrete.It exhibits the viscous effect under dynamic loading case,and the effect strengthens with the growth of the micro-crack density induced by the meso-damage of material.Combined with the Terzaghi’s effective stress principle,a dynamic damage constitutive model for the saturated concrete under uniaxial tension is proposed.The model establishes the relationship between the macro mechanical properties with the meso-damage mechanism of concrete material,which synthetically considers the influence of the inertia effect and the viscous effect of the saturated concrete under dynamic case.The inertia effect leads to the change of the failure pattern and the meso-damage evolution process of materials,and the viscous effect leads to the adjustment of the loading condition of the matrix.Comparison of the prediction with experimental data shows that it can not only reflect and predict the dynamic tensile behavior of the uniform damage phase for saturated concrete under the constant strain-rate dynamic cases,but also describe the damage evolution mechanism of saturated concrete under dynamic loading case.更多还原