混凝土单轴动态抗拉特性的试验研究

在应用过程中,混凝土结构肯定要受到动态荷载的作用,而混凝土材料的动态力学特性与静态情况下有非常大的区别.为了考察动态荷载作用下混凝土的抗拉特性,本文应用MTS试验机,对C40混凝土在应变速率为10-5/s～10-2/s范围内进行单轴动态拉伸试验,系统研究了不同应变速率下混凝土的抗拉强度、弹性模量、峰值应变等抗拉力学特性,并分析了应变速率对混凝土抗拉强度、弹性模量等的影响规律.试验结果表明:混凝土抗拉强度、弹性模量会随应变速率的增加而增加,泊松比离散性比较大,规律不明显,动态受拉应力应变曲线与静态相似.这些成果可以为混凝土的结构设计提供技术参数.

Experimental study on the uniaxial dynamic tensile properties of concrete

Concrete structures are unevitably subjected to dynamic loads.The mechanical properties of concrete under dynamic loads differ from that under static loads greatly.In order to investigate the dynamic tensile properties of concrete,dynamic tensile tests of concrete specimens(C40) are carried out on MTS,with the uniaxial strain rate ranging from 10-5 /s ~ 10-2 /s.The tensile properties of concrete under different stain rates,which include tensile strength,elastic modulus and peak strain,are studied systematically.The effect law of strain rates on the tensile strength,elastic modulus and etc.of high strength concrete are analyzed.The test results indicate that the tensile strength and elastic modulus would increase with the strain rate increasing.The discreteness of Poisson’s ratio is larger,and there has not obviously changeing formula.The stress-strain curves under dynamic tensile loads is similar to that under static loads.These findings can provide us with some technical parameters for the design of concrete structure.