Massimo Cuomo

• University of Catania

This article focuses on the derivation of explicit descriptions of networks in large deformation through the homogenization method of discrete media. Analytical models are established for the in-plane behavior of a planar periodic truss, whose cell contains a single node, as frequently encountered in practice. The cell is composed of bars that supp...

An implicit formulation for cylindrical joints (pivots) connecting slender rods in large deformations is presented exploiting the G1 map at the beam’s end. The rotation at the end of the rod is decomposed in the rotation of the pivot axis and a rotation around this axis. A mixed variational formulation that uses the spherical linear interpolation f...

A generalization of the spherical linear interpolation (or slerp) for the finite rotations to the case of more than two control variables on SO(3) is introduced to design an objective FE-formulation for the non-linear space Cosserat rod model. The interpolation uses the De Casteljau’s algorithm. In this way, the same interpolation degree can be us...

The use of raw-earth materials reinforced by natural fibres, i.e., livestock waste in the form of greasy wool, represents an eco-friendly alternative for a variety of construction applications. This proposal is based on the analysis of unfired adobe blocks stabilised with wool fibres for use as both structural and non-structural building materials....

Resonance frequencies of a masonry bell tower were estimated by means of ambient noise measurements and compared with those computed by using fixed base, Winkler, and FE numerical, including subsoil. Given the geological complexity that characterizes the subsurface of the analyzed area, despite the presence of massive volcanic outcrops near the bel...

Resonance frequencies of a masonry bell tower were estimated by means of ambient noise measurements and compared with those computed by using fixed base, Winkler, and FE numerical, including subsoil. Given the geological complexity that characterizes the subsurface of the analyzed area, despite the presence of massive volcanic outcrops near the bel...

The growing concern for the reduction of energy needs and the environmental impact of the building sector has placed emphasis on the possibilities offered by natural materials. The adoption of agricultural by-products seems to be promising and in line with the circular economy paradigm. Materials such as hemp and straw have been extensively adopted...

The interest in more environmentally sustainable building materials has led to the rediscovery of ancient and natural-based ones such as rammed earth (hereinafter RE). Nowadays, RE material is stabilized by the addition of small amount of cement in the mixture that, however, reduces its recyclability and poses concerns in terms of adverse environme...

Architected materials possess extraordinary mechanical properties, that cannot be met by natural materials, either in the static and in the dynamic range. For this reason, the study of metamaterials is a very active field of research. Although lattice architectures are commonly preferred, especially for the relative simplicity of manufacturing, geo...

A G ¹ -conforming finite element formulation based on the Kirchhoff beam model suitable for the analysis of structures composed by coupling of slender beams is presented. A new set of kinematic parameters is introduced in order to account for the continuity required by the rod model. This new set of kinematic parameters defines the G ¹ -map that gu...

The effective mechanical properties of plane fibre networks have been derived using discrete homogenization. The resulting equivalent continuum presents strong directional properties, with anisotropy ratios much larger than those that can be found in natural materials. The directionality of the response of the equivalent continuum increases with th...

Buildings of the future are called to meet increasingly high-performance requirements and to ensure adequate environmental sustainability of the production and construction chain. This issue has stimulated a keen interest in the use of natural materials in construction. Among these, raw earth has proved to be particularly interesting for its intrin...

Il rinnovato riconoscimento rivolto alla costruzione in terra cruda negli ultimi decenni e legato alla sua indubbia sostenibilita, economicita e bassa energia incorporata. In alcune zone del mondo come l'Europa, la diffusione delle tecnologie costruttive basate sull'utilizzo della terra cruda e stata spesso ostacolata dalla mancanza di una normativ...

A quadrilateral bi-cubic G1-conforming finite element for the analysis of Kirchhoff–Love shell assemblies based on the rational Gregory interpolation is presented. The Gregory interpolation removes the symmetry of the second cross derivative at the corners of the element that allows an independent control of the side rotations of the boundaries of...

Lattice fibre materials are challenging the standard modelling approaches due to their specific nature that results in peculiar effective behaviours such as extremely anisotropic materials or generalized continuum media. In this context, the aim of this paper is to the determine qualitatively and quantitatively the role of the morphological and mec...

A family of quadrilateral and triangular -conforming finite elements, based on the Gregory patch suitable for the analysis of the Kirchhoff plate model are analyzed. In the CAGD-literature Gregory Patch indicates a rational enhancement of the base-polynomial spaces, useful for designing -conforming elements on general -conforming unstructured meshe...

The paper concerns the application of an homogenization technique at the meso-scale, previously developed by the authors for the prediction of the mechanical properties of concrete-like materials, to insulating mortar. The numerical description of the meso-scale of the heterogeneous material and the determination of the heat flux is attained by usi...

The characterization of the mechanical response of complex materials, like tissues, woven composites, fibre networks etc. often requires multilevel analyses, since the micro structure strongly influences the observable behaviour. Existing approaches can be subdivided essentially into equivalent continuum or multiscale models. Often non-local contin...

Bioengineering approaches provide cost-effective ways to protect slopes against surface erosion and shallow mass movements. Indeed, vegetation is an excellent way to control slope erosion and instability of slopes. Plants play an active role both on the surface, protecting and holding soil particles, and at deeper layers, reducing pore pressure and...

Two triangular G1-conforming elements, based on the triangular Gregory patch, suitable for the analysis of the Kirchhoff plate model are presented. Both have cubic normal derivative along the sides, so that they can be effectively used in combination with generalized Hermitian elements. The Gregory patch consists in a rational enhancement of the b...

Raw earth is a traditional material used worldwide in vernacular architectures. For its wide availability, recyclability and low embodied energy in its life cycle, earth is acknowledged as one of the most environmentally sustainable material. Earth construction diffusion has been slowed by the lack of broadly accepted standards. Due to it, earth ha...

In this paper, we account for the research efforts that have been started, for some among us, already since 2003, and aimed to the design of a class of exotic architectured, optimized (meta) materials. At the first stage of these efforts, as it often happens, the research was based on the results of mathematical investigations. The problem to be so...

In complex materials there exist different, often independent, mechanisms for the evolution of anelastic phenomena at the micro- and at the macroscale. Consequently, gradient plasticity has been introduced for a large variety of non-local materials. In a similar way, continuum damage has been extended to micromorphic and other non-local models, int...

In the last decade, the exotic properties of pantographic metamaterials have been investigated and different mathematical models (both discrete or continuous) have been introduced. In a previous publication, a large part of the already existing literature about pantographic metamaterials has been presented. In this paper, we give some details about...

A quadrilateral bi-cubic G1-conforming finite element for the analysis of Kirchhoff plates is presented. The rational version of the Gregory patch proposed by Loop et al. (2009) is the starting point of our formulation. This version of the Gregory patch consists in rational enhancement of the bi-cubic Bézier interpolation representing a suitable to...

In this work we present a quadrilateral plate element for the Kirchhoff plate bending model that satisfies the continuity requirements in implicit way. The element is designed on the basis of the rational Gregory's enhancement of the bi-cubic Coons patch. This Coons-Gregory patch is based on the boundary data set of a surface, that accounts for bot...

Textile reinforced mortar (TRM) strengthening systems appear to be a preferred solution for reinforcing historical masonry structures. At present, the study of testing methods that are more appropriate for defining the mechanical design parameters is of major interest for the scientific community. The experimental research presented in this paper w...

An efficient assumed strain formulation for avoiding the membrane locking of non polar shells is developed in the context of B-spline interpolation. Assumed membrane strains are introduced locally in each element with a local L²-projection, and then a spline reconstruction algorithm, developed by Thomas et al. (2015), is employed for reconstructing...

Gradient plasticity has been introduced to predict localization bands induced by softening or damage, and has been extended to micromorphic models used for materials with microstructure and scale effects. Motivated by the consideration that in complex materials there may exist different mechanisms for the evolution of anelastic deformation at the s...

The Textile Reinforced Mortar strengthening systems (TRM) seems to be one of the better solutions to reinforce the historical masonry structures. The study of the testing methods more appropriates to define the mechanical design parameters is actually of main interest for scientific community. The experimental research presented herein was carried...

The minimum properties that allow a dissipation functional to describe a behavior of viscoplastic type are analyzed. It is considered a material model based on an internal variable description of the irreversible processes and characterized by the existence of an elastic region. The dissipation functional derived includes the case of time-independe...

Mixed formulations of the B̄ type, when applied to B-spline representations, bear significant computational cost and lead to a full stiffness matrix. In this work we present an efficient mixed formulation for avoiding membrane locking of curved non-polar plane rods in the context of isogeometric analysis. An efficient spline reconstruction of the a...

Gli interventi di stabilizzazione dei pendii con tecniche “naturalistiche”, consentono di conciliare le attività antropiche di intervento sul territorio con quelle di tutela ambientale. Essi prevedono l’utilizzo, come materiale da costruzione, di piante vive, la cui capacità di rinforzo aumenta nel tempo in modo proporzionale allo sviluppo dell’app...

The mechanical strength of FRP reinforcements for concrete elements is greatly affected by the presence of water in the concrete. A great number of investigations has concerned the effects of moisture cycles in various conditions, simulating environmental degradation. In the paper are reported the results of an experimental investigations on the st...

We consider a bi-dimensional sheet consisting of two orthogonal families of inextensible fibres. Using the representation due to Rivlin and Pipkin for admissible placements, i.e. placements preserving the lengths of the inextensible fibres, we numerically simulate a standard bias extension test on the sheet, solving a non-linear constrained optimiz...

We present a homogenized model for the analysis of a 2D continuum with two straight families of inextensible fibres embedded in it. The kinematics of the continuum is analyzed and, motivated by phenomenological observations, it is assumed that the strain energy depends on the shear deformation of the fibres and on their bending curvature. It is sho...

Concrete is an heterogeneous structural material whose constitutive behaviour is strictly depending on the mechanical properties of the aggregates and the cement paste. A large number of methods have been devoted to the prediction of the mechanical properties of this material by means of meso-scale analysis. The paper concerns a new meso-scale mode...

Concrete is a heterogeneous structural material whose constitutive behaviour is strictly depending on the mechanical properties of the aggregates and the mortar. Its behaviour is often macroscopically characterised by assigning homogenised mechanical properties. A number of methods are devoted to the prediction of the mechanical properties of the c...

Two tests for woven fabrics with orthogonal fibres are examined using simplified kinematic assumptions. The aim is to analyse how different constitutive assumptions may affect the response of the specimen. The fibres are considered inextensible, and the kinematics of 2D continua with inextensible chords due to Rivlin is adopted. In addition to two...

Concrete is an heterogeneous structural material whose constitutive behaviour is strictly depending on the mechanical properties of the aggregates and the cement paste. Its behaviour is often macroscopically characterised by assigning homogenised mechanical properties. A number of methods are devoted to the prediction of the mechanical properties o...

Concrete is a composite structural material whose constitutive behaviour is strictly depending on the mechanical properties of its constituents. The strength and the elastic modulus of the aggregates and of the cement paste define the overall response of the material and have significant influence on the macroscopic properties. In the numerical sim...

In the paper, it is considered an exact spatial Kirchhoff rod structural model. The configuration space for this model that has dimension 4 is obtained considering an ad hoc split of the rotation operator that implicitly enforces the constraints on the directors. The tangent stiffness operator, essential for the nonlinear numerical simulations, has...

A constitutive model for finite deformation anisotropic elastoplasticity, developed within the framework of the multiplicative decomposition of the deformation gradient and of the theory of the structural tensors is discussed. The main goal of the paper is to analyze the extension of finite deformation plasticity to the case that material direction...

In the framework of the reinforcement of masonry structures by FRP sheets (Fiber Reinforced Polymer), the use of “Fiber Anchor” is an innovative performing solution to increase the peak load and the dissipation capability of the strengthened system. To analyze the performance of this new technology an experimental campaign composed by 36 tests has...

Fiber reinforced composite materials are widely used for structural rehabilitation and retrofitting of existing buildings. Failure of not anchored CFRP reinforcements, applied to both concrete and masonry, mainly occurs in the substrate or at the bonding surface, for load values lower than the tensile strength of the composite. Mechanical anchors c...

A variational model for the analysis of crack evolution is presented. The method considers strong discontinuities that evolve according to the principles of cohesive fracture mechanics. A novel isogeometric interpolation scheme is presented that, differently from previous proposals, inserts the fracture modifying the blending properties of the inte...

The paper proposes an unitary strategy for the static analysis of general cable nets under conservative loads. A form-finding is first performed in order to initialize the successive non linear analysis. The numerical procedures carried on in both steps, form finding and structural analysis of the net, employ a three dimensional elastic catenary el...

. The performance of continuum elements with Embedded Discontinuities is analysed in the paper with reference to locking-free response. It is well known that in standard 4-node ele-ment models subjected to bending spurious shear stresses arise, that cause an increase in the elastic energy. Quadratic elements do not suffer of this problem. A similar...

Assessment of the effects of the application of advanced materials and new technologies on traditional structures has assumed a major relevance within the ongoing debate on the preservation of historic buildings. The aim of the present paper is to discuss the validity of analytical models, by means of experimental investigations carried out on maso...

The purpose of this study is to validate the use of piezoelectric transducers into the road asphalt pavement in terms of effectiveness and production of energy. FEM and laboratory test were conducted for transducers within an asphalt pavement, in order to study traffic load effects, the better suitable position, the pavement materials and environme...

The paper deals with the isogeometric analysis via B-splines of space rods under Kirchhoff-Love hypotheses. The approach was used by Gontier and Vollmer [12] for developing a plane curve element within the framework of the Timoshenko rod model, but they adopted only one patch to represent entirely the geometry of the rod; furthermore the authors de...

In a previous paper, the authors have proposed a local post-processing method out of the standard results of 2D FE-displacement calculations, for the evaluation of the “inter-element” forces and stress tractions transmitted across mesh lines. The method is based on a double minimization of the differences between the inter-element tractions and the...

Object of the paper is the simulation of reinforced concrete bars behaviour, accounting for crack opening and concrete-rebar slippage. A macro beam element with a single uniform reinforcement is studied in details in the uniaxial case. Distinct constitutive hypotheses are formulated for the materials. The CEB-FIP Model Code 90 rules the behaviour o...

In the paper, a model for the physical phenomenon of fracture in a continuum medium is presented. The proposed formulation falls in the context of the Strong Discontinuities Approach (SDA) implemented by means of Elements with Embedded Discontinuities (EED). In the contribution, an improved enhanced displacement field is proposed, such that the dis...

This paper deals with the isogeometric analysis using B-splines of space rods subject to Kirchhoff-Love hypotheses. A multi-patch isogeometric approach for the numerical analysis of the three-dimensional Kirchhoff-Love rod theory is developed. We use Bezier and B-splines interpolations and we show that they are able to attain very good accuracy for...

The paper deals with the isogeometric analysis via B-splines of space rods under Kirchhoff-Love hypotheses. The approach was used by Gontier and Vollmer [?] for developing a plane curve element within the framework of the Timoshenko rod model, but they adopted only one patch to represent entirely the geometry of the rod; furthermore the authors dev...

In the paper a constitutive model for finite deformation anisotropic elasto-plasticity is described. The model is developed within the framework of the multiplicative decomposition of the deformation gradient and of the theory of the structural tensors. Main goal of the paper is to analyze the extension of finite deformation plasticity to the case...

The design of cable nets and light tenso-structures requires a non conventional me-chanical analysis, due either to the non various sources of non linearity (large displacements, unilateral behaviour of the cables, non conservative loads). and to the fact that the cable do not have a reference configuration (a cable is associated to infinite refere...

The development of a Finite Element Model capable to capture cracks formation and propagation in reinforced concrete structural elements in local and global environment, in an efficient computational framework and in a suitable completeness of modeling one, represents the object of the present work. Carrying out the preliminary study of the mathema...

In the paper it is discussed a constitutive model for finite deformation anisotropic elasto-plasticity, developed within the framework of the multiplicative decomposition of the deformation gradient and of the theory of the structural tensors. Main goal of the paper is to analyze the extension of finite deformation plasticity to the case that mater...

An original implementation of the Element with Embedded Discontinuities method (EED) is presented. All the relevant equations of the model are obtained from a Hu-Washizu variational principle formulated in a general context, thus allowing also for nonlinear continua. The displacement enrichment function employed guarantees a priori continuity and t...

. The model falls in the context of the Strong Discontinuities Approach (SDA). All the relevant equations of the model are obtained from a Hu-Washizu variational principle formulated in a general context, thus allowing also for nonlinear continua. The numerical implementation in the Finite Element Method is based on Elements with Embedded Discontin...

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The paper discusses a constitutive model for finite deformation anisotropic elasto-plasticity, within the framework of the multiplicative decomposi- tion of the deformation gradient and of the theory of the structural tensors. It is shown that the driving force for the evolution of the anelastic deformation is not the classic stress, rather a therm...

A model of cohesive fracture by intra-element interfaces is presented. It uses a recently proposed algorithmic framework [4] based on the formal analogy between the enriched continuum and the theory of classical plasticity, that avoids static condensation at the element level. A variational framework including damaging embedded interfaces in the co...

Object of the contribution is the numerical modelling of the evolution of kinematical discontinuities within a continuous body, that can be due either to physical discontinuities between different materials or to opening of interfaces in an homogeneous phase. Although the physics of the phenomena is quite different, a common procedure can be adopte...

On the basis of a recent work proposed by the authors on a double-minimization method for evaluating inter-element forces and stresses transmitted across mesh lines, the crack opening conditions at a corner node of the FE mesh, from where several lines (potential cracks) emanate, is examined in this paper. The study is developed locally as a post-p...