Finite Element Analysis And Engineering Application On Cast-in-situ Concrete Hollow Flat Slab

Cast-in-situ concrete hollow flat slab is one of new type of floor system occurred in China recently,which is formed by embedding tube filler into flat slab.This kind floor system have many advantages such as lightening self-weight,insulation of thermal and sound,flexibility to scheme the floor plane,and can knock down the synthetic cost.So,this new style of floor system will be spread in the future.Compare with normal flat slab, the biggest characteristic of cast-in-suit concrete hollow flat slab is lay tube filler to form cavity. So the paper is based on this character to analysis its basic mechanic performance which is very important for right design.This paper adopt the theoretical analysis,finite element simulation and project design to study on the cast-in-situ concrete hollow flat slab which embeds with tube filler. Mainly this paper contains some parts as follow:(1)Based on classics elasticity theory,the equilibrium equation of the cast-in-situ concrete hollow flat slab is built. Analysed the two direction rigidity difference of hollow flat slab, and computated the two direction section rigidity discount coefficient of commonly used lay form in project.(2)Using finite element software ANSYS to analyse same condition performance of stress in elasticity stage between hollow flat slab and solid flat slab.Summarized the performance of distortion and the situation of the interal force distribution of hollow flat slab, it is turned out that hollow flat slab has obvious performance of bidirectional bend. Through finite element to analyse the advantageous stress performance influence of hollow flat slab because of the establishment of horizontal rib.(3)Established the reasonable finite element model of cast-in-situ concrete hollow flat slab, advance entire process nonlinear analysisment, Obtained hollow flat slab's dehiscence load,destruction load and distribution rule displacement and stress, descripted crack appear and develop of hollow flat slab, the analysis result indicated that the control sections subjected the negative moment are at the top of the slab corners, and the control sections subjected the positive moment are at the bottom of the slab in the middle span.(4) According to the depth stress analysis of hollow flat slab on chapter II and III ,put forward a reasonable form of reinforcement manner which based on mechanic performance. Discussed the flexural capacity and punching capacity of cast-in-place concrete hollow flat slab. Put forward a method of checking punching capacity at the junction of soild region and tube filler. Set out the way of punching capacity on slab-column connections and the style of punching reinforced manner. Analyse the function of the concealed wide-flat beams finally.