Elastoplastic Deformation of Clay Brick Masonry under Biaxial Stresses and Mechanisms of its Performance

Plasticity properties of the masonry appear to be key requirements in order to predict seismic response from masonry construction. On the grounds of the experimental research results, the system of mechanisms of local damage in masonry elements (brick, mortar and contact nodes thereof) is formulated and justified. It is revealed that the state of interaction nodes of basic masonry materials under increasing stress is not irreversible: when the stress state of the node changes, the discrete transition from one state to another becomes possible. The proposed system of mechanisms of local damage and the tools to analyze the state of masonry elements serves grounds for elaboration of a structural model of clay brick masonry as piece-wise homogeneous multimodule composite environment. Based on the results of numerical studies of behavior of the clay brick masonry structural model with the proposed destruction mechanisms as well as on the grounds of the strength criteria system, an accurate prediction of the elastic and plastic deformation phases can be made to determine the plasticity characteristics of the masonry under biaxial stresses.