ABSTRACT
The paper deals with unsymmetric endplate bolted connection which is suitable to resist gravity loading, but does not provide adequate resistance and ductility in earthquake conditions, when fully ductile design is required. Two full-scale dynamic tests were conducted to evaluate connection behaviour. It was then modelled numerically as a nonlinear spring, taking into account unsymmetric behaviour, pinching effect and lower ductility for the tension at the weaker side. This connection model was used in nonlinear dynamic analysis of single storey frames and portal frames subjected to earthquake excitation. The obtained results show that the behaviour of unsymmetric connection was better than one would expect. Even after bolt rupture at the weaker side of the connection the carrying capacity of frames was not exhausted. This could be good news for some existing low rise steel buildings in Slovenia, where unsymmetric connections were used instead of symmetric ones, reminding on the fact that Slovenia is a seismic area.
