混凝土动态受压力学特性的试验研究与数值分析

Experimental study on the dynamic compressive properties of concrete and the application analysis

采用MTS液压伺服系统对C30、C40两种混凝土进行了不同应变速率下的单轴抗压试验,系统研究了应变速率对混凝土抗压强度、弹性模量及应力应变曲线的影响,给出了描述混凝土在应变速率影响下的抗压强度变化的表达式;并应用有限元法,对简支梁进行了结构动力响应分析,结果表明:两种强度混凝土的抗压强度、弹性模量随着应变速率的增加呈明显增加的趋势,混凝土在动态荷载作用下的应力应变曲线与静态荷载下的应力应变曲线具有很好的相似性;同时,动态荷载作用下,梁中应力发生重分布,应变速率对混凝土结构的动力响应具有显著的影响,需要在混凝土结构设计中充分重视荷载动力效应的分析.

Uniaxial dynamic compressive tests of two kind of concrete specimens are carried out on MTS with different strain rates.The effect of strain rates on compressive strength,elastic modulus and compressive stress-strain curve of concrete are studied systematically.The formula of concrete compressive strength under the effect of strain rates is established.Using finite element method,the structure dynamic response analysis of a simply supported beam was done in this paper.The results show that the compressive strength and elastic modulus of concrete increases with the strain rate increasing,the stress-strain curves under dynamic loads is similar as that under static loads.Under dynamic loads,the stress wills redistribution in the beam.Strain rates have a significant effect on the structure dynamic response.The dynamic loads effect analysis should be considered in the concrete structure design.