Ivo Caliò

University of Catania | UNICT

A procedure tailored for a practical calibration of partial safety factors (PSF) related to input material properties is presented. The methodology addresses the propagation of material and model uncertainty through a FORM-based calibration, resulting in a noteworthy reduction in computation time compared to full probabilistic approaches. The novel...

The use of Finite Element (FE) modeling approaches for nonlinear seismic analysis of URM structures has been particularly encouraged at both the research and professional levels by increasing computational power and the incorporation of advanced material models into commercial software. These approaches can accurately simulate the complex material...

Soil-structure interaction can significantly affect the non-linear seismic response of buildings and their capacity to withstand earthquake. Rigorous modelling strategies require the explicit description of the foundation soil and the adoption of complex 3D non-linear constitutive laws for simulating the cyclic response of the soil. However, these...

In this study, the influence of concentrated damage on the stability of beams under static loads is investigated according to a co-rotational-based large displacement approach. Well-known benchmark beam-like structures have been considered under different loading conditions and damage scenarios. The concentrated damage has been modelled by means of...

The code files concern the MatLab implementation of the Dynamic Stiffness Matrix of a Timoshenko beam element with multiple cracked sections described in the paper "Exact closed-form Dynamic Stiffness Matrix of damaged frames comprising Timoshenko-Ehrenfest beams", by F. Cannizzaro, I. Fiore, S. Caddemi, I Caliò, Journal of Vibration and Control (2...

The present work proposes the extension of an exact distributional model for cracked beams to include the local influence on axial deformation on shear deformable beams. Axial, shear and flexural concentrated flexibilities are taken into account to model the damaged sections. Shear deformability is accounted for by adopting the Timoshenko–Ehrenfest...

The recent issuance of Guidelines for the classification and management of risk, safety assessment, and monitoring of existing bridges has standardized the methodology for analyzing the safety and managing bridges at a national level. The Guidelines propose a multi-level analysis approach, where the assessment of structures is conducted with increa...

This paper presents a robust and accurate P-Delta Discrete Macro-Element Method (DMEM) formulation to assess the out-of-plane (OOP) rocking behavior of masonry walls, allowing for both mechanical and geometric nonlinearities with a limited computational cost. OOPs mechanisms are one of the main causes of failure or severe damage involving historica...

Out-of-plane rocking mechanisms represent one of the major causes of damage and failure for unreinforced masonry buildings and monuments, leading to significant economic and social losses every year in many regions worldwide. Due to their slenderness, masonry walls subjected to rocking mechanisms can show large displacements before the complete ove...

The façade and internal walls of unreinforced masonry (URM) buildings often present an irregular opening layout, due to architectural reasons or modifications to the structure, which make the expected seismic damage pattern less predictable a priori. Therefore, the discretization of the walls in structural components is not standardized, conversely...

This paper presents a discrete macro-element accounting for P-Delta effects to describe the rocking response of masonry walls subjected to out-of-plane (OOP) loadings. Both constitutive and geometric nonlinearities are considered within the discrete macro-element method (DMEM), which is a modeling approach characterized by a very low computational...

The governing equation of the dynamics of the planar inextensible Euler-Bernoulli arch with multiple damage is tackled in this study by employing the distributional approach. Precisely, the presence of impairments is modelled via cracks that can be effectively embedded in the governing equation by means of the Dirac’s delta generalised functions. T...

This study presents an original inelastic beam-like model for the simulation of the nonlinear dynamic behaviour of three-dimensional buildings subjected to earthquake loadings. The proposed model is defined as a step-wise shear only cantilever beam, whose segments have the same mechanical properties of the corresponding inter-storeys of the buildin...

The presence of damage can strongly affect the residual carrying capacity and the dynamic properties of frame structures. The uncertainty in the position and intensity of damage implies the difficulty in adopting for practical purposes deterministic analyses, which rigorously require complicated calculations. In this paper, multi-cracked frames are...

Despite the numerous explicit solutions of free vibration of arches with regular cross sections, in case of concentrated defects such as cracks, no procedure is available to analyse arch vibrations without sub-division of the integration domain. As a result, curved sub-elements comprised between crack and external constraints, or successive cracks,...

Modern computational techniques have greatly influenced the numerical analyses of structures, not only in terms of calculation speed, but also in terms of procedural approach. In particular, great importance has been given to structural modelling, that is, the process by which a structure and the actions to which it is subjected are reduced to a si...

A numerical investigation is performed to investigate the potential of a discrete macro-element coupled with a mesoscale approach for the seismic assessment of unreinforced masonry structures. At first, parametric analyses are performed on a U-shape stone masonry prototype. Nonlinear static analyses are performed to investigate parameters that affe...

This paper presents two strategies for the numerical simulation of curved masonry structures. The two approaches belong to the Finite Element Model (FEM) and Discrete Macro-Element Model (DMEM) contexts, respectively. Numerical simulations of experimental tests available in the literature on unreinforced masonry arches are presented, considering bo...

Masonry infill walls are among the most vulnerable components of reinforced concrete (RC) frame structures. Recently, some techniques for enhancing the performance of the infills have been proposed, aiming at improving both the global and the local behaviour of the infilled frame structure. Among the most promising ones, there are those that aim to...

In this paper the seismic response of linear behaving structures resting on compliant soil is addressed through the application of the Preisach formalism to capture the soil nonlinearities. The novel application of the Preisach model of hysteresis for nonlinear soil-structure interaction problems is explored through the study of the seismic respons...

The mitigation of seismic risk passes through the assessment of seismic hazard of urban fabrics on a given territory. Statistical methods and damage probability matrices are currently used to facilitate seismic safety knowledge and assessment operations. These methods, despite being fast and low cost, often return results that differ from reality a...

This paper reports the results of different finite and discrete element simulations on a well-known benchmark of an unreinforced plane masonry structure. Namely, the case study concerns a five floor structural wall, located at the interior of a masonry building, situated in “via Martoglio” in the city of Catania (Italy). The numerical simulations a...

The mitigation of seismic risk passes through the assessment of seismic hazard of urban fabrics on a given territory. Statistical methods and damage probability matrices are currently used to facilitate seismic safety knowledge and assessment operations. These methods, despite being fast and low cost, often return results that differ from reality a...

In order to evaluate the static and dynamic response of multistorey buildings many researchers have focused, in the last thirty years, their attention on simplified models which allow to drastically reduce the computational effort without losing the required accuracy. In this context, with the aim of analyzing buildings characterised by a decreasin...

This paper presents numerical investigations using the mesoscale approach coupled with the discrete macro-element approach for masonry structures, i.e., each macro-element represents a single unit stone. At first, parametric analyses are performed on a U-shape masonry prototype made with stone. Nonlinear static analyses are performed to investigate...

Historical unreinforced masonry buildings represent the largest percentage of architectural and cultural heritage in several seismic areas around the world. Past and recent events have demonstrated the high vulnerability of these constructions, which are often seriously damaged even in the occurrence of moderate magnitude earthquakes, with signific...

Since ancient times masonry arch bridges have been used to cross natural obstacles. Many examples are still present and under service, particularly in European countries. Due to the historical and cultural value of these bridges, together with their important role in the transportation network system, it is necessary to have numerical tools suitabl...

This paper provides a comphrensive review of the critical aspects of nonlinear modeling for evaluating the seismic response of masonry structures, emphasizing the issues relevant to engineering practice. Currently, the specialized technical community shares the opinion that, for a performance-based approach, numerical models are the only tools suff...

The numerical modelling of the torsion behaviour of masonry block interfaces is a key aspect for the assessment of the out-of-plane response of masonry walls. Nevertheless, it still represents a challenging computational issue due to the high non-linear coupling between the torsion and other internal forces (shear, bending moment and axial load), w...

This paper adopts the use of steel frames around existing openings as a low-impact seismic retrofitting strategy for unreinforced masonry structures (URM). Although elastic steel frames have been commonly adopted for strengthening masonry walls in case of the realization of new openings, the use of elasto-plastic frames has been proposed only recen...

Existing unreinforced masonry (URM) buildings, including historical and monumental structures, represent an important architectural and cultural heritage for several countries worldwide. The response of URM, subjected to earthquake excitations, is strongly governed by the out-of-plane (OOP) response of masonry walls, which can lead to local failure...

Earthquakes may damage buildings, but they also induce uplift and overturn the content of a building that, in the case of museums, can lead to the irreparable loss of art objects. In many cases, these objects, subjected to seismic actions, can be modeled considering the nonlinear dynamics of rigid blocks. This paper is focused on the seismic behavi...

The ‘baraccato’ system is a construction technique with genius earthquake resilient features, used for the reconstruction of the historical city centres in the South of Italy after the catastrophic events occurred in the 18th-19th centuries. A very interesting example of such a building typology is represented by the Church of Santa Maria Maddalena...

Recent earthquakes have shown that the seismic behavior of non-code conforming reinforced concrete buildings are in several cases strongly affected by the nonlinear response and possible failure of the beam-column joints. Beam column joint inelasticity is typically due to either shear cracking and failure of the central concrete panel or bond-slip...

The paper presents a novel 3D macroelement approach for efficient and accurate nonlinear analysis of unreinforced masonry components subjected to in-plane and out-of-plane cyclic loading. A macroscopic description for masonry is employed, where macroelements, consisting of deformable blocks interacting through cohesive interfaces, are used to repre...

The seismic response of masonry structures without box-type behaviour is given by a complex interaction between in-plane and out-of-plane behaviours. Previous earthquakes demonstrated that out-of-plane failure mechanisms represent the main cause of structural collapses of UnReinforced Masonry (URM) and historical structures. Previous experimental a...

The influence of damage in beam-like structures is a problem widely analysed in the literature in view of its importance towards the assessment of the residual carrying capacity and the evaluation of the inevitable changes of the dynamic properties. Usually, the dynamic properties and the forced vibrations of structures, cannot be explicitly inferr...

Dynamic analyses and seismic assessments of multi-storey buildings at the urban level require large-scale simulations and computational procedures based on simplified but accurate numerical models. For this aim, the present paper proposes an equivalent non-uniform beam-like model, suitable for the dynamic analysis of buildings with an asymmetric pl...

This paper aims at providing an insightful comparison between three of the most widely used commercially available macroelement models for assessing the global seismic performance of existing masonry structures: the equivalent frame model of 3Muri®, and the two- and three-dimensional discrete macroelements available in 3DMacro®. To this aim, a ston...

The analysis of multi-storey frames by means of simplified models, introduced in the last century, is still a subject of current interest since it allows drastically containing the required computational burden. Aiming at simulating the static and dynamic behaviour of entire buildings, beam-like models, equivalent to framed structures, have been fo...

Damage in beams can strongly affect their dynamic properties and consequently their response. On the other hand, the correct evaluation of the damage intensity is a problem of difficult solution. For these reasons, exploring the variability of the dynamic response in damaged beams considering the damage intensities as uncertain parameter is a usefu...

Dynamic analyses and seismic assessments of multi-storey buildings at urban level require large-scale simulations and computational procedures based on simplified but accurate numerical models. At this aim the present paper propos-es an equivalent non-uniform beam-like model, suitable for the dynamic analysis of buildings with asymmetric plan and n...

This paper studies the inverse problem related to the identification of the flexural stiffness of an Euler Bernoulli beam to reconstruct its profile starting from available response data. The proposed identification procedure makes use of energy measurements and is based on the application of a closed form solution for the static displacements of m...

The assessment of the seismic vulnerability of unreinforced masonry (URM) structures based on numerical modeling constitutes a difficult task due to their complex behavior, especially in the nonlinear dynamic field, and the lack of suitable, low-demanding, computational tools. In the last decades, practical statistical tools for the derivation of f...

The analysis of multi-storey frames by means of simplified models, introduced in the last century, is still a subject of current interest since it allows drastically containing the required computational burden. Aiming at simulating the static and dynamic behaviour of entire buildings, beam-like models, equivalent to framed structures, have been fo...

The analysis of multi-storey frames by means of equivalent models, introduced in the last century, is a still extremely current subject as it allows drastically containing the computational burden. Aiming at simulating the static and dynamic behaviour of entire buildings, some recent studies have been devoted to formulate beam-like models based on...

The structural response of masonry arches is strongly dominated by the arch geometry, the stone block dimensions and the interaction with backfill material or surrounding walls. Due to their intrinsic discontinuous nature, the nonlinear structural response of these key historical structures can be efficiently modelled in the context of discrete ele...

Beam finite elements for non linear plastic analysis of beam-like structures are formulated according to Displacement Based (DB) or Force Based (FB) approaches. DB formulations rely on modelling the displacement field by means of displacement shape functions. Despite the greater simplicity of DB over FB approaches, the latter provide more accurate...

Beam finite elements for non linear plastic analysis of beam-like structures are formulated according to Displacement Based (DB) or Force Based (FB) approaches. DB formulations rely on modelling the displacement field by means of displacement shape functions. Despite the greater simplicity of DB over FB approaches, the latter provide more accurate...

This paper investigates the out-of-plane response of masonry façades under earthquakes by means of two different approaches. A discrete macro-element approach, based on modelling the structure by means of spatial deformable macro-elements interacting through nonlinear zero-thickness interfaces, and the classical approach in which the masonry façade...

The numerical modelling of the torsion behaviour of masonry block joints represents a key aspect for the assessment of the out-of-plane response of masonry walls. However, it represents a challenging computational issue due to the high non-linear coupling between the torsion and other internal forces (shear, bending moment and axial load), meaning...

In order to estimate the seismic vulnerability of a densely populated urban area; it would in principle be necessary to evaluate the dynamic behaviour of individual and aggregate buildings. These detailed seismic analyses, however, are extremely cost-intensive and require great processing time and expertise judgment. The aim of the present study is...

conference Masonry multi-span arch bridges are historical structures still playing a key role in many transportation networks of numerous countries. Most of these bridges are several decades old and have been subjected to continuous dynamic loadings, due to the vehicular traffic, and in many cases their maintenance required structural modifications...

The numerical prediction of masonry monumental structures is a complex issue, due to the difficulties in adequately simulating the nonlinear cyclic response of masonry material. In principle, nonlinear finite element modeling (FEM) can be rigorously applied for large monumental structures. However, these approaches still require high computational...