Experimental study on the dynamic response of mass timber post-and-beam frames under a column removal scenario

Abstract

In recent years, mid-rise to tall mass timber buildings gained international popularity. To ensure robust buildings and the safety of human lives, such buildings are required to be designed to resist progressive collapse. Progressive collapse is a dynamic event associated with large deformations and nonlinearities. Its mechanisms must be understood to eventually develop realistic design guidelines. To gain a preliminary understanding on the dynamic behaviour of mass timber buildings under a sudden column removal scenario, a series of dynamic tests on scaled down 2D post-and-beam substructures have been designed and conducted. The structures were manufactured with three types of currently used beam-to-column connectors. Different dynamic loading stages, considering elastic and plastic behaviours, were adopted. The displacement-based and force-based dynamic increase factors (DIF) were calculated from the dynamic and associated static experimental results. It was found that the value of the DIF depends on the connector type and its associated failure mode. Preliminary analysis tended to indicate that the theoretical dynamic load-deflection curves plotted using the simplified assessment framework method reasonable predict the dynamic responses for all connectors.