Reinforced Concrete Ribbed Floor Nonlinear Mechanical Behavior Of Numerical Analysis

A bearing capacity of cast Waffle Slab is based on the common Tic-Tac-ribbed floor and on the use of reusable plastic shell developed high stiffness of slab form, especially for the underground garage, libraries, shopping malls and other large span, large column grid construction, its economic and social benefits significantly, broad application prospects.The current analysis and experimental research on this type of floor of the theory of finite theories lag and engineering practice, its design, calculation and analysis methods are mainly concentrated in the elastic phase range and structure cracks into the less plastic stage of analysis, experimental research, high cost, long cycle, for in-depth understanding of the mechanical behavior investigate into the nonlinear stage of the ribbed floor, in view of the above problems, the paper uses theory and finite element numerical calculation method of combining, for in-situ shuttering secret ribbed Floor mainly for the following research areas:(1) the use of general-purpose finite element software ANSYS, four sides of a simply-supported reinforced concrete ribbed floor loading the whole process from the beginning to destroy the system, the whole process of analysis to calculate, in rib slab of nonlinear mechanics row, its load, deformation, and cracks have developed a comprehensive, in-depth understanding.(2) the development of cracks nonlinear finite element analysis, in contrast to the two-way slab crack, analyzed and discussed based on the plastic hinge line method to determine the ribbed floor limit loads. Raised floor under the simplified elastic stage deflection is calculated by the load-deflection curve to analyze changes in the stiffness of the roof cover.(3) single-span surrounding the elastic support of ribbed floor nonlinear analysis. Uniform load simulation structure internal force and deformation under the effect of the development and changes, identify weak local practice designed to analyze the impact ribbed load floor height of the bear, to provide reference for the design.By studying the following conclusions:finite element analysis results of simply supported-ribbed plastic hinge line with four edges simply support bi-directional board similar; the plastic hinge line method determined ribbed floor ultimate bearing capacity and finite element analysis the results agree well; by floor deflection under load development has been simplified stiffness curve, a simplified formula for calculating the maximum deflection of the elastic stage floor. Single span surrounding the elastic support of ribbed floor rib stress mainly concentrated in the beam, the beam span rib stress larger to smaller sides; the central area maximum deformation, and stress is usually the biggest part of the support of the four sides; floor cracks first appeared in the bottom floor of the rib across the beam, as load increases, the column cap across the upper edge and the upper floor has cracks.