Multisurface Interface Model for Analysis of Masonry Structures

TLDR

The study evaluates an interface elastoplastic constitutive model for unreinforced masonry analysis. The model discretizes masonry into a unit‑joint framework using softening plasticity for tension, shear, and compression, with parameters derived from micro‑experiments and implemented via Newton‑Raphson and implicit integration. The model accurately predicts collapse loads and post‑peak behavior of masonry shear walls, providing detailed insight into force flow and stress redistribution.

Abstract

The performance of an interface elastoplastic constitutive model for the analysis of unreinforced masonry structures is evaluated. Both masonry components are discretized aiming at a rational unit-joint model able to describe cracking, slip, and crushing of the material. The model is formulated in the spirit of softening plasticity for tension, shear and compression, with consistent treatment of the intersections defined by these modes. The numerical implementation is based on modern algorithmic concepts such as local and global Newton-Raphson methods, implicit integration of the rate equations and consistent tangent stiffness matrices. The parameters necessary to define the model are derived from microexperiments in units, joints, and small masonry samples. The model is used to analyze masonry shear-walls and is capable of predicting the experimental collapse load and behaviour accurately. Detailed comparisons between experimental and numerical results permit a clear understanding of the walls structural behavior, flow of internal forces and redistribution of stresses both in the preand post-peak regime.