Behaviour of welded beam-to-column joints with beams of unequal depth

• The behaviour of internal joints with beams of unequal depths is characterised
• Numerical models are prepared and calibrated with experimental results from tests on full scale joints.
• A behaviour model, in line with the component method, is developed for asymmetric joints.
• A modified analytical method is implemented that covers the design asymmetrical joints.
• The modified analytical model for the asymmetrical joints is validated.

The objective of the current paper is to characterise the behaviour of internal asymmetric joints, which corresponds to a node configuration that is not yet covered in the EN 1993-1-8 design rules.For this purpose, a research programme was established that encompasses five different types of joints. Numerical models were prepared and calibrated with results from experimental tests on full scale models of the joints. The analyses of the results allowed the identification of the main features that influence the behaviour of asymmetric joints. This information was used to establish a behavioural model consistent with the component method philosophy.Furthermore, the analytical method supporting the component method was investigated, and the information gathered about the behaviour of the new configuration was used to tailor the reference model for the design of asymmetric joints.The modified analytical model was implemented for the asymmetric joints studied. The results were compared with those of the homologous calibrated numerical models. The quality of the adjustment was established in terms of the parameters representing the moment rotation curve for a joint, within the framework of the component method, and a quite reasonable adjustment is observed.