The Effect of Random Spatial Variability in Masonry Bricks Unit Material Properties on the Structural Performance of Unreinforced Masonry Walls

This paper presents the numerical analyses aimed at investigating the effect of correlated random fields properties - such as elastic modulus, compression resistance, and deformation at peak compression - of masonry brick units on the in-plane behavior of Unreinforced Masonry (URM) wall using a finite element model (FEM). Non-linear analyses are developed by applying an in-plane horizontal displacement load and iteratively changing the correlated random field material properties of the wall's masonry brick units while keeping the value of the vertical compression stress applied on the wall constant. Firstly, the random field model's reliability is verified by comparing it with an established deterministic model and a documented experimental test result from the literature. The same model is then used to investigate the influence of uncertainties of the material properties of brick units on the global behavior of the URM wall. The random field numerical analysis results show the considerable effect of the spatially varying material properties of masonry brick units on the macro performance of the masonry wall in terms of ultimate strength and failure modes. The results also demonstrate the influence of the cross-correlation between the random fields of masonry brick unit elastic modulus, compression resistance, and tensile resistance on the global behavior of the wall.

Keywords: Masonry, Random fields, Uncertainty propagation, Spatial variability, Cross-correlation.