LAGRANGE ANALYSIS OF THE STRESS-STRAIN RELATION OF CONCRETE MATERIAL UNDER IMPACT

Dynamic constitutive properties of concrete material play important roles in the analysis of concrete structures subjected to impact loading. Lagrange analysis is useful to study dynamic performance of material, especially the material constitutive relation. A set of strain profiles at several different locations of concrete specimen have been measured using a modified right cone 74-mm-diameter Hopkinson pressure bar as loading equipment. By Lagrange analysis, the stress-strain relation of concrete material under dynamic loading is obtained. The strain rate effect of concrete material and the influence of repetitious load on dynamic properties of material is also discussed. The method of Lagrange analysis is extended and some suggestions are indicated when Lagrange analysis are used to analyze concrete material.