混凝土动态损伤的滞后特性  

Mechanism of dynamic damage delay characteristic of concrete

作　　者：马怀发[1] 王立涛[1] 陈厚群[1] 李德玉[1] 

机构地区：[1]中国水利水电科学研究院工程抗震研究中心,北京100048

出　　处：《水利学报》2010年第6期659-664,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点资助项目(90510017);水利部公益专项(200701004;200901054)

摘　　要：混凝土材料在动载作用下存在应变率敏感效应,其产生机理尚待深入研究。本文总结了混凝土材料动态力学性能的基本规律,并基于混凝土在损伤过程中声发射凯塞效应的观测及相关研究成果,分析研究了惯性效应、预静载和水的黏性等因素对动载作用下混凝土材料的损伤滞后特性的影响,提出了在动载作用下混凝土材料变形滞后所产生的损伤滞后最终表现为应变率强化效应的观点。同时,通过全级配混凝土试件的弯折数值模拟计算,并基于动载作用下的变形滞后的观点,讨论了所引入率效应强化参数的物理意义。Concrete materials exhibit much sensitivity of mechanical behaviors to loading rates or strain rates,but the mechanism of strain rate effect induced is not well understood.Based on the observation of acoustic emission tests and the related literatures,the damage delay characteristics of concrete under dynamic loading are investigated and it is revealed that the strain-rate effect is originated from the deformation delay resulted in damage delay.The numerical simulations of specimens of fully-graded concrete are conducted to study the influence of inertial force,static preloading and water viscosity on the dynamic damage delay of the concrete as well as the physical meanings of the involved dynamic strength enhancing coefficients in view of the deformation delay.

关 键 词：混凝土 应变率效应 损伤滞后 凯塞效应 

分 类 号：TV312[水利工程—水工结构工程]