ABSTRACT
The strength of unreinforced masonry (URM) walls subjected to one way bending under out-of-plane loading (no pre-compression) is known to be affected by the masonry unit tensile bond strength. Factors such as batching, workmanship, and environmental exposure alter the strength of this bond, resulting in spatial variability for any URM assembly. This paper focuses on a preliminary stochastic assessment of clay brick URM walls with spatially variable tensile bond strength subjected to uniformly distributed out-of-plane loads in one-way vertical bending. Stochastic computational modelling combining Finite Element Analysis (FEA) and Monte Carlo Simulation (MCS) is used to account for bond strength variability when estimating the walls ultimate failure loads. Previously, this approach has been used to study the effect of material variability on cracking loads, failure loads, and failure modes of URM walls in one and two-way bending. For this preliminary assessment FEA MCS has been applied to a subset of existing test data for walls with consistent properties constructed by ten different masons. For these walls a 3D non-linear FEA model was developed, followed by a stochastic analysis for which the unit tensile bond strength is spatially varied according to the measured flexural tensile bond strength and its coefficient of variation. For a set of simulations the peak load and load-displacement data was extracted and analysed, showing good agreement with the results of wall test data.
