Biaxial Stress‐strain Relations for Brick Masonry

Simple nonlinear stress‐strain relations for brick masonry constructed with solid pressed bricks are derived from the results of a large number of biaxial tests on square panels with various angles of the bed joint to the principal stress axes. The macroscopic elastic and nonlinear stress‐strain relations are determined from, displacement measurements over gage lengths which included a number of mortar joints. Although the initial elastic behavior is found to be close, on average, to isotropic, the nonlinear behavior is strongly influenced by joint deformations and is best expressed in terms of stresses and strains referred to axes normal and parallel to the bed joint. A given strain is related only to the corresponding stress by a power law, except when the ratio of the shear to normal stress on a bed joint is greater than 1. In the latter case, a bilinear relation is more appropriate. Dependence on other stress components is masked by the variability in the results.