Constitutive behaviour of quasi-brittle materials with anisotropic friction

Abstract

This paper presents an approach to a constitutive model for anisotropic quasi-brittle materials, developed in the framework of rate independent softening plasticity, involving a yield criterion in which an anisotropic friction tensor is involved. It turns out to be useful for materials characterized by ultimate behaviour which varies according to the direction, such as composite materials, anisotropic rocks, textiles, masonry. A geometrical representation of the limit domain in the case of plane stress, together with the results of laboratory tests is presented and discussed.

Rigid block models for masonry structures

“…The original structural approach here proposed, following in the steps of Heyman and Huerta, has been the object of study of a group of researchers of the University of Salerno and Napoli, among which the first author played a leading part (see for example Angelillo et al (2010Angelillo et al ( , 2012, Fortunato et al (2016Fortunato et al ( , 2018, Angelillo and Fortunato (2004) and De Serio et al (2018)) and references therein). The main object of the research of this group is the implementation of numerical methods based on the unilateral model for masonry, through computer codes allowing to predict the effect of forces and settlements, and assess the safety of real structures Angelillo et al, 2005Angelillo et al, , 2016Fraldi et al, 2009;Cennamo et al, 2013;Chiozzi et al, 2017;Monaco et al, 2014;Gesualdo and Monaco, 2015) Quality of masonry. It is worfirth pointing out that Heyman's model applies to structures composed of masonry elements having the quality of masonry, that is built with the rules of art and whose building blocks have a sufficient integrity.…”

Mechanical properties of traditional lime mortars

“…Unfortunately the drawing of sufficient mortar samples is a difficult task to be performed, given the small dimensions of the mortar joints. The reliable information available from in situ tests is relative to physical-chemical properties, while the strength properties can be derived from by suitable theoretical models developed for the entire masonry (Gesualdo and Monaco, 2015). The Vicat's studies (Vicat, 1818(Vicat, , 1856 are the first systematic researches on the mechanical properties of the lime mortars.…”

Rocking of freestanding objects: theoretical and experimental comparisons

“…Within the limits of linear approximation, the correct expression that yields the minimum acceleration required to overturn a block is derived. Under realistic conditions, the rocking response of a rigid block is affected by additional factors such as the vertical component of the ground acceleration and the additional energy loss due to plastic deformations at the pivot points (Gesualdo and Monaco, 2015). Recent attempts to derive equivalence between a single rocking block and various rocking mechanisms in order to give indication for real structures has been made (Spanos et al, 2001; DeJong and Dimitrakopoulos, 2014).…”