Macroscale modelling of microstructure damage evolution by a rigid body and spring model

Abstract

A mechanistic approach is presented for macroscale modelling of a structured solid material. The model consists of an assemblage of rigid mass-elements connected to each other by normal and shear linesprings at each side. The characteristics of these springs govern the macroscopic behaviour of the model that is able to incorporate an internal length and a polarity, in analogy with an orthotropic Cosserat solid material. The present numerical implementation addresses the in-plane modelling of a masonry-like composite whose main macroscopic constitutive aspects are: very low tensile strength, texture-dependent evolution of the damage, and orthotropy of shear strength and internal friction. The constitutive rules are assigned by following a heuristic approach, based on the main in-plane damage mechanisms that are identified at the mesoscale, on a representative volume element of the composite solid material. In particular, specific separate constitutive laws for the normal and the shear springs are adopted. Two numerical tests compare the present macroscale approach with a detailed finite element micromodelling, and demonstrate the capability of the proposed model to describe the main microstructure features of the damaging process with very few degrees of freedom.

Laser-Scanner Survey of Structural Disorders: An Instrument To Inspect the History of Parma Cathedral’s Central Nave

“…The contiguous blocks interact with constraints of no-tension, unilateral type contact, elastic in compression; the sliding between the blocks considers the effect of friction. In keeping with the classic approach to this method, the real masonry texture of the arches was faithfully reproduced in the model (Casolo, 2009). The main issue, as previously exposed, was whether to adopt, as a base for the structural model, the present, deformed configuration or the original, undeformed one (Shi and Goodman, 1998).…”

Seismic Modelling and Analysis of Masonry Building in Aggregate: A Case Study

“…This model can describe higher vibration modes, as well as the combined axial and shear deformation and damage of the material by means of a simplified heuristic approach, which has been developed both for the out-of-plane behaviour [23][24][25][26][27] and for the in-plane behaviour [3][4][6][7] here applied. The application of the mentioned RBSM model is particularly effective since it allows to considerably reduce the computational burden while keeping, at the same time, the information about the meso-scale effects of the masonry behavior.…”

“…After developing and testing vulnerability methods at the regional scale, a detailed study was performed on masonry aggregate buildings in the City of Foggia. In particular, the paper presents the results of a series of mechanical analysis performed first by Finite Element Modeling [5] and then by a specific Rigid Body and Spring Model [3,4,6,7]. As a case study, a representative structural typology of the ancient historical center of Foggia was chosen, with the objective of characterizing the seismic response of local building types and allowing the validation of the 1 st level vulnerability assessment already carried out in the Project but also, in the future, the derivation of specific fragility curves.…”

Further Developments of a Simplified Modelling of Infilled Frames for Reinforced Concrete Buildings

“…If they are applied to structural systems that require a limited number of elements, they allow to reduce the computational burden required by the continuous or discontinuous approaches. The Rigid Body Spring Model (RBSM), consists in describing the masonry as a mechanism composed of the unitary cells constituted by of rigid blocks and elastic-plastic springs [6,20] (Figure 1). Through this approach, it is possible to model the masonry panels at the "macro-scale" through a kinematic that takes into account the specific effects of masonry texture.…”