Seismic Resistance of Flush Endplate Connections

The application of semi-rigid flush endplate connections to the seismic design of steel frames is investigated experimentally. Two test series are described in which specific connection details are varied and the effects on stiffhess, resistance and ductility observed. Cyclic loading conditions representative of earthquake structural response are employed in each test. The observed plastic response mode, resistance and stiffness are compared with those predicted by Eurocode 3. While specimen stiffness did not vary greatly between tests, large differences in ductility were observed. Although intended for monotonic loading conditons, the provisions of the design Code proved adequate in determining whether a ductile or brittle failure would occur, but seriously underpredicted the ultimate resistance of the specimens. Such conservatism, which was most evident in the more ductile specimens, has implications for earthquake-resistant column design in which an upper bound on connection strength is required.

A.W. Thompson and B.M. Broderick