Mechanical Behavior And Design Of Integral Composite Frame Beams With End-plate Connections

Focus on the deficiencies of composite frames design,the integral composite frame beams with end-plate connections was proposed.the design method and construction of this composite frame beam was given,the mechanical behavior in both positive and negative bending moment were studied,the main contents of this paper are as follows:Firstly,referring to Chinese and American specification about the design of the composite beams and end plate connections,a trial design of the integral composite frame beams with end-plate connections was made.Secondly,according to results obtained from trial design,numerical simulation of the integral composite frame beams with end-plate connections was carried by using ABAQUS,and the key technology,such as the type of unit for modeling,the bolt preload,the contact interface model,as well as materials properties,was verified to be applicable.Thirdly,based on the numerical simulation,parametric analysis about the integral composite frame beams with end-plate connections was carried.The main parameter include as follow:the diameter of steel bar in the range of column width,the strength of concrete,the width of steel column flange,etc.Finally,according to the results of numerical simulation,improve the calculation about the effective width of the integral composite frame beams with end-plate connections.Based on the analytical research above,main conclusions can be listed as follow:(1)Compared with the pure steel frame beam,the integral composite frame beam with end-plate connections has a significantly advantage on the ultimate capacity and initial stiffness.Because of the participation of concrete slab,the bottom flange of beam was more dangerous than the top one.The connect between steel rebar and end-plate increase the ultimate capacity and initial stiffness of composite frame beams.The width of steel column flange also has effect on the ultimate capacity and initial stiffness.However,the strength of concrete has no effect on it.(2)The effective width of the integral composite frame beams with end-plate connections under positive moment increases when the width of steel column flange increases and it declines when the width of steel beam flange increases.The effective width of the integral composite frame beams with end-plate connections under negative moment can be calculated by using the method in trial design.In conclusion,by using the integral composite frame beams with end-plate connections,the frame beams can be a composite member,in addition the design model can be consistent with the working model,thereby,the mechanical behavior of frame beam was improved.