Dynamic behaviour of web cleat connections subjected to sudden column removal scenario

• Dynamic behaviour was observed for web cleat connection under sudden column loss.
• Numerical models were validated by comparing with static and dynamic test results.
• Full dynamic responses of the web cleat connection were investigated.
• A DIF of 2.8 is suggested for simple connections to resist progressive collapse.

In this paper, experimental tests and numerical analyses were carried out to investigate the dynamic behaviour of web cleat beam-column connections subjected to sudden column removal scenario. In the test programme, different magnitudes of uniformly distributed loads were applied at the two-side-beam spans which were connected to a middle column with double angle web cleat connections on both sides of the central column. Both dynamic and static tests were conducted to gain a better understanding of the dynamic effects on structural performance. Test results showed that the maximum displacement of the web cleat connections under sudden column removal would be significantly increased compared with the one under static loading condition. Both force- and displacement-based Dynamic Increase Factors (DIFs) were measured from the tests. Besides, a three-dimensional numerical model was developed using commercial finite element software ABAQUS which was validated by comparing with the experimental observed response. Based on the proposed finite element model, parametric studies on load release time were carried out. The dynamic response of the connections which was defined as the relationship between the initial support force of the middle column and the maximum dynamic displacement, was also investigated. The analyses results showed that the maximum dynamic load capacity of this web cleat connection was about 2.8 times lower than its static load capacity.