Study On Influence Of Beam-to-slab Relative Stiffness On Moment Of Cast-in-situ Slab

Cast-in-situ RC beam-slab floor system is the one which is the most widely used at present. It has great effect on the safety and economy. Beams and slabs of cast-in-situ RC floor system are integrated and act each other. Each of them contacts the others very tightly. They bear the load and are deformed together. But in the methods of designing the cast-in- situ RC floor system under the gravity load, beams and slabs are divided practically. The method has some errors. Force distribution and deformation correspondence of cast-in-situ RC floor system under the gravity load are still complex.In this paper, finite element analysis software ANSYS are used for floor system calculation model with nonlinear finite elements. This paper mainly study on the influence of beam-to-slab relative stiffness and length-width ratio of floor on floor moment, and try to find out the cooperating work performance of beam-slab floor system under the gravity load. Then this paper synthetically analysis internal force law of cast-in-situ RC frame beam-slab floor system under the gravity load. Compared with result from the elasticity theory, this paper brings forward floor moment modification coefficients of mid-panel, side panel and corner panel. Apply the coefficients to multiply the results from the elasticity theory, accurate slab moment can be gained. To improve the simplified method based on the elasticity theory on slab moment, some suggestions for design of beam and slab in cast-in-situ RC floor system is presented, which help to avoid safety hidden trouble and stop wasting, then make the design of floor system more safe, reasonable and economic.