CONSTITUTIVE MODELING OF CONCRETE FOR NON-LINEAR FINITE ELEMENT ANALYSIS OF STRUCTURAL ELEMENTS

Abstract

In present study, a FORTRAJ'4 code for a constitutive model proposed by Holmquist et al which has been incorporated in Abaqus/Explicit and numerical simulations of experiments carried out by Hanchak et al are done to ascertain the behavior of concrete structures under impact loading under the effect of missile penetrations. Computations are presented for a penetrator impacting a concrete target and results are compares to test data. Impact loading on structures either accidental or anti-social activities like terrorism is currently evident in most part of the world. An impact loading exerts a shock of high intensity and very short duration locally on the structure. Hence ièw buildings of national and strategic importance has to be desiied for overall safety and to prevent fatal damages. Due to high stresses and strains material behavior of concrete and steel is very complex to be predicted under impact loading. Material modeling has been discussed in details with the help of numerical simulations. Holmquist .Johnson Cook model commonly known as HJC model has been used for concrete and Johnson Cook model has been used for reinforcing steel. The study carried out on a model consist of a reinforced concrete plate having concrete of grade M 48 and three layer of square pattern reinforcement. The velocity of impact of rigid missile was varied from 300m/s to I lOOm's to study the residual velocity afler penetration into the target structure. Finite element code Abaqus/Explicit was used for the simulations. Analysis results are given in terms of residual velocity of the projectile and results are validated from the test results of experiments performed by Hanchak ci al. It has been observed that the code developed for constitutive model proposed by Holrnquist c/ al is giving satisãctory results.