Al-Rafidain Engineering Journal (AREJ)

Abstract

Abstract
This study includes the effect of cyclic heating and repeated loading on the behavior of reinforced concrete thick plates by using mathematical models to represent the effect of cyclic heating on mechanical properties of concrete and steel, and other models to represent the behavior of both concrete and steel underth effect of cyclic loads.
Plate thickness has been divided into several layers; steel was represented as an equivalent concrete layer. The material properties in each layer of the plate thickness are evaluated according to its temperature. One dimensional heat equation has been used to describe heat distribution through the layers
Reissener’s theory that account for shear strain and transfer of shear forces and assumes that stress distribution across plate thickness is linear has been used to analyze the plates. The finite difference method and dynamic relaxation technique are used to calculate the stress and strain in the plate; also modified increment method is used to represent stress-strain nonlinear relationship.
Reinforced concrete plates have been analyzed in the ordinary temperature and after heating and cooling for three different temperatures (200,400,600)˚C withdifferent Cyclic Loading of (1,2,3,4) cycles .

Keywords: Nonlinear analysis, Reinforced concrete, Thick plates, Repeated load, High Temperature.