Sequentially linear modelling of local snap-back in extremely brittle structures

In the present paper a sequentially linear approach is proposed for the finite element analysis of extremely brittle structures. A peculiar definition of the saw-tooth approximation of the softening branch is presented, which allows for a straightforward discretization of the softening branch in the case of snap-back on a constitutive level. In this way the well-known limit of the smeared crack approach is overcome, and extremely brittle structures, i.e. with a very low ratio between the fracture energy and the finite element size, can be modeled without the need of an extreme mesh refinement. The model is applied to a novel ‘reinforced glass beam’ concept by the Faculty of Architecture at the Delft University of Technology. The sequentially linear analysis results in terms of load–deflection curves and crack patterns, obtained with different relatively coarse meshes, are in good agreement with the experimental results.