An accurate finite element model to study the progressive collapse of post-and-beam mass timber buildings

Abstract

The structural behaviour of mass timber buildings under the removal of a load bearing element is complex. To well understand this phenomenon and ultimately develop scientifically based design guidelines against progressive collapse for this type of buildings, there is a need to develop Finite Element models which accurately capture the nonlinear structural responses of such buildings. This paper presents how mass timber post-and-beam systems can be accurately modelled using Finite Element under edge and corner column removal scenarios. The model was validated against published 3D experimental tests performed on scaled-down substructures. Results show that the model accurately replicated non-linear behaviour, load redistribution mechanisms, ultimate loads, failure modes, and strain developments. The use of the model was then illustrated by running parametric studies to quantify (i) the influence of the Cross Laminated Timber (CLT) floor panels layout and (ii) one alternative load path, typically ignored in design, on the progressive collapse resistance capacity.