Analisys of masonry structures modelled with rigid blocks and unilateral contatc constraints

The paper is concerned with a numerical procedure available for the analysis of voussoir arches, or any other masonry structure, modelled on a discrete system of rigid blocks connected by unilateral elastic contact constraints. A convenient way to define the contact device which links the blocks, through which a mortar joint could be simulated, is to consider a curtain of elastic bars, orthogonal to the contact surface between two adjacent blocks, and an additional bar tangent to the same contact surface. In accordance with the assumptions of no tensile strength in the mortar joint, only compressive forces can be transmitted from one element to another. Through the results of the numerical procedure it is possible both to define the cracking failure pattern, highlighting the actual reacting structure within the apparent one, and to evaluate the width of the cracks located in the mortar joints.