Calibrating failure surfaces for vertically perforated clay block masonry using a validated numerical unit cell model

Abstract

Finite element software is nowadays an essential part of a structural engineer's modeling process. The simulations range from trivial linear elastic models to highly non-linear ones, accounting for contact, plasticity, viscoelasticity, or fracture. Though fired clay blocks are an excellent and widely used building material, little effort has been made to extend available failure surfaces for simulating vertically perforated clay block masonry in modern FE Software. Therefore, developing reliable and efficient ways to predict the effective strength of vertically perforated clay block masonry subjected to different loading states is critical. In this study, we aim to qualitatively analyze the failure surface of vertically perforated clay block masonry under in-plane loading, using numerical simulations. Using a previously validated unit cell FE model, we derived the peak stresses from 471 simulations. Subsequently, we compared these results with two failure surfaces from the literature and identified qualitative differences. Taking these differences into account, we propose a concept for numerically calibrating the parameters of the Rankine–Hill failure surface proposed by Lourenço (1997).