Numerical analysis of historical masonry domes: A study of St. Peter’s Basilica dome

Abstract

Large historical masonry domes are usually constructions of great cultural importance and therefore are often subjected to numerical analysis. The analysis aims to find the causes of structural damage arising from different loading combinations. This paper is concerned with demonstrating the application of plastic material models in the Finite Element Method for assessment of masonry structures with the dome of St. Peter’s Basilica with its support system including drum, buttresses, arcs and pillars as an example. 3-D solid elements were used in the analysis because of the dome’s complex geometry, which contains a double shell interconnected by ribs and surrounded by buttresses, and is characterized by a high thickness to diameter ratio. The Model was built in Abaqus CAE using Concrete Damaged Plasticity (CDP) material to accommodate the plastic behavior of masonry in both compression and tension modes which arise from the dome’s geometry. The Model displays good convergence between plastic strain due to tension and historical data on the dome’s cracks and thus should be seen as an appropriate tool for qualitative analysis providing for better understanding of structural damages. The plastic Model provides an opportunity to track the development of cracks, to consider the resulting stress redistribution arising from increasing load and to attribute the existing crack patterns to the best fitting load condition.