Calibration of FEM models of historic masonry structures and its application on a local historic structure

Abstract

Masonry structures may be of different kinds, including stone, brick and other masonry blocks assembled in different ways using mortar. For study of such structures, modelling them is necessary which can be done in two ways, either by modelling large classes of masonry as single units (Simple Model) or by regular arrangement of blocks and the interaction between blocks and mortar (Refined Model). Simple Model approach takes crude material assumptions and produces results affected by large approximations, while the second approach is sophisticated and close to reality. The present research deals with the creation of a method for modelling of Finite Element Models of masonry buildings through their fast regenerative modelling in an environment offered by Rhinoceros 3D and Grasshopper. Since exact modelling of such structures is complicated and time-consuming, macro modelling of such structures is carried out by simplistic assumptions of the structural system as load bearing walls. Simple architectural plans of each storey may be imported from AutoCAD to Rhinoceros 3D, scaled according to the dimensions. These can then be assigned as geometry in Grasshopper and extruded in Z-direction (according to storey height) to get the basic volume of the curves. The plan of each storey can then be placed on top of one another by maintaining a distance equal to the storey height and the whole 3D model may be created. These models are user friendly and consume very less time, if definitions for extrusion and openings etc. are created beforehand in Grasshopper, and can be used for multiple structures. Such macro models are then used for simple static analysis by using a similar script in Grasshopper or may be imported to other Finite Element Analysis (FEA) softwares.