混凝土单轴动态强度理论的探讨

在分析相关试验结果的基础上,系统地对混凝土在单轴动态加载下的强度特征进行了研究分析。结果表明,不仅加载速率对动态强度有着重要的影响,加载速率对材料弹性参数的影响也很大。结果显示:①混凝土在加载初始阶段,应力—应变表现为线性关系,可认为混凝土处于弹性阶段;随着压力的增加,混凝土产生非线性变形,并出现峰后应力下降;②混凝土的抗压极限强度随着加载速率的增加而增加;③混凝土的弹性模量随着加载速率的增加而提高,而泊松比保持不变。最终提出了一种改进的弹性损伤动态强度的本构理论。

Exploration of Uniaxial Dynamic Strength Theory of Concrete

Based on the relevant experimental results,a symmetrical analysis of dynamic strength behavior of concrete under uniaxial loading was carried out.Study shows that strain rate has an important influence not only on the dynamic strength but also on the elastic parameters of concrete.It is concluded that: with the increasing of the pressure,the concrete behaves from elastic to nonlinear deformation and shows a strength drop;ultimate compressive strength and elastic modulus of concrete increase with increase of strain rate,while Poisson′s ratio remains stable.Finally,this paper presents an improved elastic damage dynamic strength constitutive theory.