Nonlinear Finite Element Analysis On Steel Truss Coupling Beam With Friction Joints

Steel truss coupling beam with friction joints refers to embedding friction dampers in the diagonal web member of steel truss coupling beam.Tests have proved that its ductility is better,and its load-displacement hysteresis curve is very full.Steel truss coupling beam with friction joints mainly rely on the sliding of friction joints and plastic deformation of chord member to dissipate energy.Its stiffness of initial sliding is relatively large,but after sliding,the stiffness becomes relatively small,making it easy to be maintained and realizing the energy dissipation and damping control concept of relatively large stiffness in small shocks and relatively small stiffness in medium and strong earthquake.Contents and results of this thesis are summarized as follows:1.This thesis takes the concrete plastic damage model into consideration.Based on experiments,the author uses finite element software ABAQUS to make a simulative analysis on shear wall constructional elements of steel truss coupling beam with friction joints,and simulate its bearing capability under low reversed cyclic loading.After comparing the theoretical analysis and experimental results,it is found that the nonlinear finite element analysis method possesses high accuracy.According to the analysis of parameters of this thesis,the enhancements that bolt pre-tightening force bring to the ultimate bearing capacity of coupling beam almost increase linearly,however,if the bearing capacity beyond a certain limit,brittle failure of coupling beam will occur suddenly.The enhancement of diagonal web member within a certain range can effectively guarantee start-up of the damper and improve bearing capacity of the structure,while over the range will make almost no contribution to normal start-up of the damper and bearing capacity of the structure.The enhancement of chord member can prevent integral instability and increase ductility of the structure,moreover,bringing almost no effect to the ultimate bearing capacity.2.Based on the existing experimental studies,the author uses test fitting method to establish the restoring force model of steel truss coupling beam with friction joints.This Model is in good conformity with the experimental results,which proves that it can provide scientific theory for the research of anti-seismic capability of itself.3.Using the finite element analysis software ABAQUS to establish a finite element model of 12-storey short shear wall structure of steel trusses coupling beam with friction joints,so as to make spectrum analysis,and at the same time input seismic waves to make nonlinear time-history analysis under the small earthquakes and large earthquakes,extracting its acceleration response,displacement response,and energy dissipation curve.Comparing with the finite element model of ordinary short shear wall,it is proved that the short shear wall of steel truss coupling beam with friction joints has superior anti-seismic capability.Besides,the author discusses different distributions of steel truss coupling beam with friction joints,degrees of bolt pre-tightening force and other factors affecting the anti-seismic capability of coupling beam shear wall,which provides the basis for the reasonable macro layout of steel truss coupling beam with friction joints.