| The mechanic property of diagonal end-plate beam-column connection in portal frame is very complicate due to its semi-rigidity, and local buckling of beam and column, especially when subjected to earthquake action. As there is very rare in experimental study and theoretical analysis, this article performed tests on its hysteretic behavior.Three half-scale specimens of diagonal end-plate beam-column connections were designed firstly, and data measurement, loading scheme were determined according to analysis results of finite element method. Then, test was carried out under cyclic loading to study the influence of the end-plate thickness and the high strength bolts strength grades on the seismic performance. The failure mode, rotational rigidity, bearing capacity, and energy dissipation ability, are obtained based on test results. It revealed that appropriate increasing the end-plate thickness or enhancing strength grades of high strength bolts, can both improve the bearing capacity and rotational rigidity of diagonal end-plate beam-column connection; the hysteresis curves are not plump, and the energy dissipation capacity is very poor, so the seismic capacity of the connection should be increased by its own resistance; the destruction of each joint is beam flange buckling failure, and the node area is flexible; the connection failed due to local buckling in top flange of beam, so the design satisfied the demand of "strong connection, weak component, strong column and weak beam" concept by code; the semi-rigidity may not consider in calculating bearing capacity of connection due to not failure in connection components; and the neutral axis of bolts lies in the centroid of bolts in terms of force distribution of bolts.Finally, some suggestions on design of diagonal end-plate beam-column connection were put forward, which can be referred in practice design. |
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