【摘要】 为了研究荷载历史对混凝土应力应变全曲线、动态抗压强度及应力和应变空间动态损伤特性的影响,在应变速率10-5/s～10-2/s范围内,对历经了0%、30%、50%和75%极限抗压强度荷载历史后的普通混凝土受压试件进行了单轴动态抗压试验。试验结果表明,不同应变速率下历经荷载历史后,混凝土应力应变全曲线发生明显的变化;混凝土动态抗压强度随着应变速率的增加而增加,荷载历史超过某一槛值后,混凝土抗压极限强度明显降低;混凝土损伤应力槛值随着应变速率的增加而增加,历经超过损伤槛值的荷载历史后,混凝土的损伤应力槛值随着荷载历史的增加而减小,且损伤值随着荷载历史的增加而增加;混凝土损伤应变槛值受应变速率的影响不大,但随着荷载历史的增加而减小,且损伤值随着荷载历史的增加而增加。更多还原

【Abstract】 A dynamic compressive test of concrete specimens, experienced load histories of 0%, 30%, 50% and 75% ultimate strengths, was carried out on the static-dynamic triaxial test system, with the strain rates range from 10-5/s to 10-2/s. Effects of load histories on the strain-stress curve, the compressive strength, the dynamic damage behavior in stress and strain spaces at different strain rates were studied. Results show that the strain-stress curve of concrete is effected obviously by strain rates and load histories. The compressive strength of concrete increases with the strain rate and decreases when the load history exceeds the damage stress threshold. In the stress space, the damage stress threshold of concrete increases with the strain rate. When the load history exceeds the damage stress threshold, the damage stress threshold decreases with the strain rate and the damage value increases with the load history. In the strain space, the damage strain threshold of concrete is independent on the strain rate but decreases with the load history. The damage value increases with the load history.更多还原