应变率对混凝土动态力学特性的影响研究

Study on the dynamic mechanical property of concrete under different strain rate

混凝土材料的动态力学特性受应变速率的影响比较明显。从数值试验出发,根据自行编制的混凝土随机骨料细观模型,分别计算了动压和动拉荷载作用下,不同加载速率对混凝土动态力学特性的影响。结果发现:混凝土材料在动压和动拉荷载作用下都存在率效应,它们对速率的响应不尽相同,动拉荷载作用下,材料的率效应更明显;材料的动压强度明显大于动拉强度,两者基本相差10倍;随着应变率的增大,破坏强度增大,破坏位移也变大。应变率会改变试件的破坏位置,但不会改变试件的破坏形态。

The dynamic mechanical properties of concrete materials are obviously influenced by the strain rate. Based on numerical experiment,according to the concrete random aggregate mesoscopic model,the dynamic pressure and dynamic tensile loads were calculated respectively. The influence of different loading rate on the dynamic mechanical properties of concrete was analyzed. The results showed that: Concrete material existence rate effect under the dynamic pressure and dynamic tensile loads. Their response to the rate is not the same. The material rate effect is more obvious under the dynamic tensile load. The dynamic compressive strength of the material is obviously greater than that of the dynamic tensile strength. The former is 10 times the latter. With the increase of the strain rate,the failure strength increases,and the damage displacement becomes larger. The strain rate will change the damage position of the specimen,but will not change the failure mode of the specimen.