Damping models for dynamic analysis of masonry vaults with discrete elements

Abstract

Discrete element block models provide a suitable tool for the numerical analysis of masonry structures, particularly apt to represent the nonlinear response governed by shearing and separation along the structure’s joints and discontinuities. Arches and vaults have been successfully analyzed with this approach, for static and dynamic loading. For time domain dynamic analysis, the selection of damping is of critical importance. In this paper, the standard Rayleigh damping model is discussed and compared with an alternative damping model, based on the use of Maxwell elements in the contacts between blocks. The performance of the alternative formulation is analysed for vaulted structures, using rigid and deformable block models, under pulse and seismic loading. Maxwell damping is shown to provide solutions for vault failure loads and mechanisms which are comparable to stiffness-proportional Rayleigh damping, but with significant computational advantages for explicit solution algorithms.