NONLINEAR FINITE ELEMENT PROCEDURES FOR THE STRUCTURAL EVALUATION OF MASONRY MONUMENTAL BUILDINGS UNDER SEISMIC LOADING

Renato Perucchio, Department of Mechanical Engineering, University of Rochester

Hopeman 224

In this talk we will discuss an energy based numerical approach developed to detect collapse conditions for complex masonry structures under seismic loading modelled within a nonlinear Finite Element (FE) explicit formulation. The structural assessment of masonry heritage monuments requires a multidisciplinary approach involving the integration of historical information, diagnostic inspections, experimental tests, and numerical structural analysis. Because of the pronounced weakness in tension of masonry material, heritage masonry structures are particularly vulnerable to earthquakes. In addition to the architectural complexity typical of monumental buildings, FE modeling of masonry structures is a daunting task due to the inhomogeneity, anisotropy, and quasi-brittle behavior of masonry material. A pushover analysis in which the structure is subjected to loading conditions representing peak ground horizontal accelerations is a standard numerical test for evaluating the structural capacity to lateral loading. Performing pushover analysis of masonry heritage structures is tricky and becomes particularly challenging when displacement-control of the nonlinear FE solution is required in order to capture the softening part of the structural response. In the course of the study of heritage masonry monuments our lab has developed a new approach to evaluating the onset of collapse conditions based on the time-dependent evolution of internal energy components under quasi-static conditions. The application of this approach will be illustrated in the structural evaluation of the triumphal arch of the Church of Andahuyalillas near Cusco, Peru, of the Frigidarium of the Baths of Diocletian in Rome, and of the curtain wall of the Elmina Castle, Ghana.