The Reifnement Study On The Impact Dynamics Performance Of Plain Concrete

Usually the inertia effect and the friction effect produced in the impact dynamictest on plain concrete would bring unnecessary errors even inaccuracies in the finalresult of test. Although now there are many research achievements related to theseeffects, one academic debate about the mechanism research of how the inertial effectand the friction effect affect the dynamic strength of plain concrete under dynamicloads is still not unified.Therefor, based on the C40concrete, test on various sizes plain concretespecimens were performed under static compressive loading and dynamiccompressive loading. And the numerical simulation of dynamic compressive behaviorof plain concrete was studied, the inertial effect and the friction effect on the dynamicstrength of plain concrete and its dynamic increase factor (DIF) were analyzed. Andspecific work as follows:1. The inertial effect’s influence on the plain concrete specimens with varioussizes including Ф22㎜×11㎜、Ф32㎜×16㎜、Ф40㎜×20㎜under static compressiveloads was analyzed. The friction effect’s influence on the plain concrete specimenswith various sizes including Ф32㎜×10㎜、Ф32㎜×20㎜、Ф32㎜×30㎜by the staticcompressive test and surveying the static friction coefficient was also analyzed. Andthe load-time relationship of plain concrete specimens was achieved by analyzing thetesting data.2. Theoretical analysis on the inertial effect and the friction effect produced in theplain concrete specimens under dynamic compressive loads by the Hopkinsonseparate pressure bar (SHPB) experiment was performed.3. Test on the plain concrete specimens with six various sizes above underdynamic compressive loads was conducted by SHPB testing apparatus. And thechange graphs of stress wave during SHPB test, and strain rate-time curves、stress-strain curves、peak stress-strain rate curves of the plain concrete specimenswere achieved by analyzing the testing data. The inertial effect and the frictioneffect’s influence on the dynamic strength of plain concrete specimens were analyzed.4. The expression of DIF-strain rate of plain concrete was proposed in this thesis,and the inertial effect and the friction effect’s quantitative influence on DIF were also analyzed.5. By the finite element analysis software ANSYS/LS-DYNA with HJCconstitutive model, the numerical simulation of dynamic compressive behavior ofplain concrete by the SHPB testing method was studied, and the comparison betweenresult of the numerical simulation and testing result was analyzed.Finally, by summarizing the contents in this thesis, some things related to thisproject needing to be improved and further studied were put forward.