Composite Beams Considering Slip Elastic Analysis Of Flexure And Compression Elastic-plastic Calculation

In this thesis,the chief content is to count and analyse the deformation and receiving power capability of composite beam considering the slippage of steel-concrete interface in the stage of elasticity,and introduce the problems that will be solved when analyzing the elasto-plastic stage of construct under axial power and bending moment.Firstly,in the elastic stage,the slip of steel-concrete interface,the deflection of composite beam,the strain distribution on composite section are counted when simply supported composite beam whit evenly fixed shear connectors is under even load or uniformly distributed load,and compared with the deflection counted using methods introduced other literatures,reached the limitations of computational method that GB50017-2003 gives.And define the scope of GB50017-2003 formula by way of many cardinalitys according to counting.The finite element computational method is used in this thesis,considering the slip of steel-concrete interface,the freedom degrees of nodal of composite beam increase from 3 to 4,anthor derivated one-dimensional element stiffness matrix and verified its correct nature.Secondly,according to theory derivation,the finite element program applicated by anthor is used to calculate and analyse flowing several aspects of composite beam: the composite bean property,namely the interface shear distribution,the axial force distribution in the concrete board,the strain distribution on the section;in the simply supported composite beam,the distribution of slip steel-concrete interface and axial force in the concrete board,the influence of deformation caused by the distribution form of shear connectors;the influence of deformation of two equal span continuous composite beam caused by the distribution form of shear connectors;in the continuous composite beam,and how to control the concrete cracks in the negative bending moment region.According to the above analysis,some conclusion may be referenced in the engineering practice.Finally,considering that the components of composite beam,concrete board cell and steel beam cell,are under axial force and bending moment at the same time,they belong to press(pull)-bending members,the element stiffness matrix of press(pull)-bending members during the stage is derivted,and introduced the correction of element stiffness and total stiffness matrix,adjustment of the plastic stress,and the contraction norm;With the upper method and the stiffness matrix enrolls among the program,an example is given,and contrast with the computational solution of commerce finite element software ANSYS,concludes the correct nature of element stiffness matrix,it is convenient to do elasto-plastic analysis of composite beam.