چكيده به لاتين
Abstract:
Although several theories and corresponding design procedures for structural concrete subjected to shear have been proposed, no universally accepted rational method of shear design has evolved. There are two main approaches for analysis of reinforced concrete structures: 1) discrete crack approach, which models cracks discretely; and 2) smeared crack approach, which models cracks by applying an equivalent theory of continuum mechanics. In this research, the smeared crack approach is selected in which the stresses and strains of concrete and steel are evaluated by the average or smeared values crossing several cracks.
Examining the experimental studies on membrane reinforced concrete panels and utilizing the optimizition algorithms, a set of intractive constitutive laws for reinforced concrete were revised. Remarkable charachtristics of the constitutive laws are: 1) accounting the influence of reinforcement ratio on the average stress-strain curve of cracked concrete; and 2) considering the effects of crack angle on the tension stiffening phenomena.Therefore, the influence of reinforcing bars on tension behavior of concrete after cracking is accounted as a function of their angle against the tension cracks. Combining the eqilibrium, compatibility, and constitutive equations in an efficient algorithm, a procedure for nonlinear analysis of membrane reiforced concrete elements is achieved. Comparison between the resaults of proposed model and experimental studies showed a good accuracy of this model on predicting load-deformation response of elements.
Keywords: Reinforced Concrete, Membrane Elements, Nonlinear Analysis, Rotating Smeared Crack.
