Study On Mechanical Behavior Of New-type Bolted End-plate Connections With Slotted Holes

The end-plate connection with slotted holes studied in this paper is a new type of steel beam-to-column connection, which improve the seismic behavior of the joints by the application of slotted holes. Such new-type end-plate joint exhibits great ductility^ large capacity of consuming energy and easiness of repair.This paper put forward a preliminary design method of the new-type end-plate connection according to the existing standards and performed a design. Based on the test and finite element model, Hysteretic Behavior of the connections were investigated, and consequently, combining the experiment of the joints and FEM analysis results, preliminary design method is revised.By applying low-cycle reciprocating load on six new-type end-plate connections, one traditional end-plate connection and one reduce beam section connection, deformation capacity, load-carrying capacity, energy dissipation of the connections and other mechanical characteristics were investigated, all the results were compared with the reduce beam section connection and traditional end-plate connection.The test result showed that: new-type end plate connections’ load-carrying capacity were 1.3～1.4 larger than that of reduce beam section connection; new-type end plate connections’ ductility coefficient were between 17.5 and 26.4,1.8～2.78 larger than traditional end-plate connection,1.68～2.54 larger than the reduce beam section connection, new-type end-plate connection’s ductility can be controlled through the size of the slotted bolt holes; new-type end-plate connections’ limiting rotation angle were between 0.083 and 0.126,2.1～3.15 larger than reduce beam section connection,1.77～2.68 larger than traditional end-plate connection; new-type end-plate connections’ largest hysteretic energy coefficient were 1.77～3.58 larger than traditional end-plate,1.26-2.56 larger than reduce beam section connection; new-type end-plate connections’ sum of hysteretic energy coefficient were 2.45～4.48 larger than traditional end-plate,1.62～2.97 larger than traditional end-plate, The new-type end-plate connections’ total energy consumption were 1.77～3.13 large than traditional end-plate,1.87～2.55 larger than the reduce beam section connection. the contribution of slotted holes on frictional energy consumption occupies 7.8%-47.5% of the total energy consumption, Thus, energy consumption ability can significantly increase by.the use of slotted holes.Non-linear finite element model is established by using Abaqus, the hysteretic curve, failure mode, deformation of the joint according to the FEM agreed well with the test results, the limit state of finite element results was conservative. FEM result showed that load pry force formula of the preliminary designed method is not applicable to that of the ultimate state.The experimental and FEM results showed that:1) the moment should be chosen at the center of bolts group when check the bolts on the beam flange:1) the center of rotation transfers from the system axis of the beam section to the compressive end plate of the roots at the ultimate state; 2) simplifying the end plate to two T-stubs on the beam flanges is not right at the ultimate state, it should be considered as one integrity.