An alternative design for internal and external semi-rigid composite joints. Part I: Experimental research

An experimental program has been carried out to test and characterize an innovative design for internal and external semi-rigid composite joints. Three tests are performed on semi-rigid composite joints with flush end plates. One of the tests deals with an internal joint with asymmetric loads, and the other two with external joints. When compared with the usual configuration of this type of joint, the proposed alternative design introduces an innovation which consists in inserting the central reinforcement bars through the column flanges in order to achieve an improved behaviour. In addition, in the case of external joints, the cantilever normally needed to ensure sufficient anchorage length for the reinforcement can be dispensed with.The experimental results are used to calibrate the finite element models. These are used to conduct a parametric study and to propose some modifications to the Eurocode 4 component method, as can be seen in the companion paper.