The seismic performance of a semi-rigid composite joint with a double-sided extended end-plate. Part I: Experimental research

Composite structures exhibit higher stiffness than steel structures with similar ductility, and also show better performance to fire action. These benefits have led to an increase in the number of composite structures built in high seismic areas. The main objective of the experimental tests explained in this article is to obtain useful data about the seismic behaviour of a composite semi-rigid joint with a double-sided extended end-plate. A series of monotonic and cyclic quasi-static tests was performed to characterize the behaviour of this joint type against seismic actions. The tests were performed on interior and on exterior joints, and they have provided useful data about the ductility of the joint, the amount of energy dissipated and the degradation effects.This data was used to elaborate and calibrate a component-based model of the joint that is composed of two rotational springs, one for the shear panel behaviour and the other for the connection behaviour. This model is capable of simulating the joint behaviour and damage under cyclic loads with sufficient accuracy.