Research On Performance-based Plastic Design Of Two Special Truss Moment Frames With Double Special Segment

The research in this dissertation was based on the previous research of Special Truss Moment Frames(STMF),which has the deficiency of large deformation on the special segment on truss.Two type variants of STMF with double special segment was proposed to solve the deficiency.Based on the frame of Performance-Based Plastic Design(PBPD)method,this dissertation studied the design method for the proposed variants of STMF.Major Achievements and works are as follow:1)The yield mechanisms of the STMF variants was proposed,the finite element software was used to verify the yield mechanism,from the results,the yield mechanism was found rational and acceptable,which can reflect the plastic behavior in the structure to a certain extent.The preparation has been made for PBPD method for the two variants.2)Based on the proposed yield mechanisms and the frame of PBPD method,the design methods for the two variants were proposed.The equation was proposed to calculate the parameters which determine the sections of energy dissipation component.According to different structure layouts of the two variants,the free body represents the non-energy dissipation part was extract from the entire structure,moreover,the calculation methods of external forces on those free bodies were also given.3)Base on the potential application of this variants,example cases of the variants was designed according to the methods proposed in this dissertation.Moreover,as being a control group,STMFs were also designed based on the method proposed by the previous researcher.Those works were done for the purpose of examining the validity of the proposed methods.The nonlinear static pushover analysis was conducted to check the validity of the design parameters.Based on the acceleration design spectra,12 natural seismic acceleration records were chosen,and 2 artificial seismic acceleration records were generated.They were scaled to 3 levels to perform the nonlinear dynamic timehistory analysis and to investigate the performance of the variants.4)Based on the results of nonlinear static pushover analysis,the parameters chosen for the example case was rational and acceptable.Based on the results of the nonlinear dynamic time-history analysis,the average interstory drifts of the variant were all below the limit of specifications and the selected target drift.In addition,the plastic deformation of the special segment,the parameters related to the proposed method was also checked.Plastic deformation of special segment of the examples was all below the extreme deformation,the components outside the special segment were kept elastic in most cases,which realize the aim of the proposed method.5)After the validity of variants was confirmed,several advice for design has been given.