Analysis of masonry in complex state of stress -determination of scalar damage parameter

The determination of the state of deformation of masonry structures is usually based on FEM and should taking into consideration the real material parameters. Of course these parameters are changing with relation of the state of stress and corresponded state of strain. Masonry is a typically elastic-plastic material with brittle failure mode. Therefore there is necessary to describe the change of the stress and strain states due damage appearance. From design point of view the describing of the degradation process of the elastic stiffness is very important. In proposed paper, according to the test data, the kinetics of damage evolution for masonry walls subjected to vertical shearing (with and without precompression) has been elaborated. Based on them the proposed method of determination of the scalar parameter ω value and shear modulus reduction is presented.