干燥和饱和混凝土动态力学特性及其机理  

Dynamic mechanical properties of dry and saturated concretes and their mechanism

作　　者：张永亮[1,2,3] 朱大勇[1,3] 李永池[2] 姚华彦[1,2,3] 黄瑞源[2] 李煦阳[2] 

机构地区：[1]合肥工业大学土木与水利工程学院,安徽合肥230009 [2]中国科学技术大学近代力学系,安徽合肥230027 [3]合肥工业大学安徽土木工程结构与材料省级实验室,安徽合肥230009

出　　处：《爆炸与冲击》2015年第6期864-870,共7页Explosion and Shock Waves

基　　金：国家自然科学基金青年基金项目(11102205;11202206);中国博士后科学基金项目(20100480685)

摘　　要：采用分离式Hopkinson杆装置,对混凝土进行干燥和饱和状态下的SHPB实验,并与准静态实验进行对比。结果表明:干燥和饱和混凝土均具有明显的应变率效应,中等应变率条件下的应力应变曲线上升段比准静态的曲线陡;饱和混凝土动态强度提高的幅度接近干燥混凝土的2倍,具有更强的应变率敏感性;存在一个应变率临界值,仅当应变率大于临界值时,饱和混凝土的动态强度才大于干燥混凝土的的动态强度;基于实验结果,给出了不同饱和度混凝土强度与应变率的关系。We carried out SHPB tests on dry and saturated concretes using split Hopkinson and they were compared with quasi-static mechanical tests. The results show that the dry and saturated concretes produce an obvious strain rate effect., the ascending part of the stress-strain curve at moderate strain rate is steeper than that of the quasi-static curve; the increasing amplitude of dynamic strength of the saturated concrete, which has a stronger sensitivity to the strain rate, is nearly twice as that of the dry concrete; and there is a threshold of the strain rate, i. e. , it is only when the strain rate exceeds this threshold that the dynamic strength of the saturated concrete becomes stronger than that of the dry concrete. Based on the experimental results, the equation showing the relationship between the concrete strength and the strain rate at different saturations is established and given.

关 键 词：固体力学 临界应变率 SHPB试验 混凝土材料 Stefan效应 

分 类 号：O347.3[理学—固体力学]