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2012 Report Closed Access

Analisi strutturale della chiesa di San Francesco a Lucca: modellazione di alcuni interventi di consolidamento [project report 2]
Girardi M., Padovani C., Pagni A., Pasquinelli G.
Research project "Structural analysis of the church of San Francesco in Lucca: modelling of some strengthening operations" - project reportSource: Project report, 2012

See at: CNR ExploRA Restricted


2012 Report Closed Access

Analisi strutturale della chiesa di San Francesco a Lucca: modellazione di alcuni interventi di consolidamento [project report 1]
Girardi M., Padovani C., Pagni A., Pasquinelli G.
Research project "Structural analysis of the church of San Francesco in Lucca: modelling of some strengthening operations" - project reportSource: Project report, 2012

See at: CNR ExploRA Restricted


2012 Conference article Restricted

The NOSA-ITACA code for the modelling of the structural behaviour of historic masonry constructions
Binante V., Girardi M., Padovani C., Pagni A., Pasquinelli G.
The paper presents a new numerical tool, the NOSA-ITACA code, for the structural analysis of masonry buildings of historical interest. The code, resulting from integration of the finite element code NOSA and the open-source platform SALOME, is being developed within the framework of the NOSA-ITACA project, funded by the Region of Tuscany. In this paper some preliminary results are described with the aim of illustrating the main features of the NOSA-ITACA code. After a short description of the constitutive equation used to model the mechanical behaviour of masonry constructions, some details are given concerning the code's implementation. Lastly, a dynamic analysis of the "Rognosa" tower in San Gimignano, performed via the NOSA-ITACA code, is presented to exemplify application of the code.Source: 5th International Congress on "Science and Technology for the Safeguard of Cultural Heritage in the Mediterranean Basin", pp. 40–48, Istanbul, Turkey, 22-25 november 2011

See at: CNR ExploRA Restricted


2011 Journal article Restricted

Free longitudinal vibrations of bimodular beams: a comparative study
Denis Kharenko, Cristina Padovani, Andrea Pagni, Giuseppe Pasquinelli, Leonid Semin
In this paper, we consider the problem of the free longitudinal vibrations of a beam made of a bimodular material, i.e. an elastic material whose in-tension Young's modulus is a fraction of that under compression. After recalling the exact solutions for an infinite beam and for a beam with fixed ends calculated via the characteristics method, we apply high-resolution methods based on the finite-element approach to solve the nonlinear equation of the motion. In particular, we compare the exact solutions with the numerical solutions calculated using the collocation and least-squares method developed in the present study, the space-time element method, as well as total variation diminishing (TVD) and Newmark methods.Source: International journal of structural stability and dynamics. 11 (2011): 23–56. doi:10.1142/S0219455411003975
DOI: 10.1142/s0219455411003975

See at: International Journal of Structural Stability and Dynamics Restricted | CNR ExploRA Restricted | International Journal of Structural Stability and Dynamics Restricted | International Journal of Structural Stability and Dynamics Restricted


2011 Journal article Restricted

A thermomechanical solver for multilayer power electronic assemblies integrated into the DJOSER thermal simulator
Bagnoli P. E., Padovani C., Pagni A., Pasquinelli G.
The DJOSER analytical thermal solver for multilayer mounting structures has been tested as a useful and friendly tool for the thermal analysis of power electronic devices and their packages, able to replace the onerous programs based on the finite element method (FEM) calculations. The other problem connected with the packaging evaluation is the calculation of the thermally induced stresses and strains in the various layers composing the assembling structures. This paper deals with the first step of the implementation of a thermomechanical solver to be connected with the DJOSER program, which is able to calculate the stresses at the layer interfaces, using the same strategy, i.e., a semianalytical mathematical approach, as well as the same structural models (stepped pyramidal structures and homogeneous layers). The basic theory is briefly exposed and the method is applied to some two-layer virtual structures. The obtained results are compared with those obtained using standard FEM analyses.Source: Journal of electronic packaging 133 (2011): 011005-1–011005-7. doi:10.1115/1.4003516
DOI: 10.1115/1.4003516

See at: Journal of Electronic Packaging Restricted | Journal of Electronic Packaging Restricted | Journal of Electronic Packaging Restricted | Journal of Electronic Packaging Restricted | asmedl.org Restricted | Journal of Electronic Packaging Restricted | Journal of Electronic Packaging Restricted | CNR ExploRA Restricted


2011 Conference article Restricted

Thermoelastic behaviour of masonry-like solids with temperature-dependent Young's modulus
Girardi Maria, Padovani Cristina, Pagni Andrea, Pasquinelli Giuseppe
In this paper, by limiting the treatment to thermomechanical uncoupling, we study the behaviour of masonry-like materials and analyse the influence of the temperature dependence of the Young's modulus on the stress field and crack distribution in a spherical container subjected to internal and external uniform radial pressures and steady temperature distributions. If the Young's modulus E does not depend on temperature, the solution to the equilibrium problem can be calculated explicitly. Instead, when E depends on temperature, the solution is calculated numerically via the finite element code NOSA. The solutions corresponding to constant and temperature-dependent Young's moduli are compared, and the influence of the temperature dependence of E on the specific heat is assessed.Source: The Thirteenth International Conference in Civil, Structural and Environmental Engineering Computing, Chania, Creete, Greece, 6-9 September 2011

See at: CNR ExploRA Restricted


2011 Contribution to conference Open Access OPEN

The NOSA-ITACA code for the modelling of the structural behaviour of historic masonry constructions
Binante Vincenzo, Girardi Maria, Padovani Cristina, Pagni Andrea, Pasquinelli Giuseppe
The paper presents a new numerical tool, the NOSA-ITACA code, for the structural analysis of masonry buildings of historical interest. The code, resulting from integration of the finite element code NOSA and the open-source platform SALOME, is being developed within the framework of the NOSA-ITACA project, funded by the Region of Tuscany. In this paper some preliminary results are described with the aim of illustrating the main features of the NOSA-ITACA code. After a short description of the constitutive equation used to model the mechanical behaviour of masonry constructions, some details are given concerning the code's implementation. Lastly, a dynamic analysis of the "Rognosa" tower in San Gimignano, performed via the NOSA-ITACA code, is presented to exemplify application of the code.Source: 5th International Congress on "Science and Technology for the Safeguard of Cultural Heritage in the Mediterranean Basin", pp. 1–30, Istanbul - Turkey, 22-25 november 2011

See at: ISTI Repository Open Access | CNR ExploRA Open Access


2011 Report Unknown

Sviluppo del codice NOSA-GRAPH per l'analisi strutturale di costruzioni in muratura di interesse storico e architettonico
Girardi M., Padovani C., Pagni A., Pasquinelli G.
Project Report "Development of the NOSA-GRAPH code for the structural analysis of masonry buildings of historical and architectural interest". Funded by the Fondazione Cassa di Risparmio di Lucca, 2010-2011Source: Project report, 2011

See at: CNR ExploRA


2010 Conference article Restricted

Thermo-mechanical analysis of 3-d multilayer structures for power electronic devices
Bagnoli P. E., Girardi M., Padovani C., Pagni A., Pasquinelli G.
An integrated simulation tool for multilayer stepped pyramidal structures, able to calculate the temperature distributions and thermal stresses at the interfaces between the layers and based on a semi-analytical mathematical strategy is presented. The core of the thermal solver is the analytical simulator DJOSER for power electronic devices. DJOSER is then integrated with a mechanical solver based on the finite element method. A new element is proposed whose geometry is defined by its mean surface and thickness, just like in a plate, and whose mechanical behaviour is fully three-dimensional, in the sense that the deformability in the direction orthogonal to the mean surface is taken into account. The dedicated finite element code developed for solving the equilibrium problem of structures made up of two or more superimposed plates subjected to thermal loads is applied to some two-layer samples made of silicon and copper. The comparisons with the results of standard finite element analyses using a large number of brick elements are presented and discussed. © 2010 IEEE.Source: Third International Conference on Thermal Issues in Emerging Technologies - Theory and Applications, pp. 69–75, Cairo, Egitto, 19-22 December 2010
DOI: 10.1109/theta.2010.5766381

See at: academic.microsoft.com Restricted | arpi.unipi.it Restricted | CNR ExploRA Restricted | xplorestaging.ieee.org Restricted | yadda.icm.edu.pl Restricted


2010 Conference article Closed Access

The "Rognosa" tower in San Gimignano: digital acquisition and structural analysis
Callieri M., Corsini M., Girardi M., Padovani C., Pagni A., Pasquinelli G., Scopigno R.
The paper describes the research activities conducted on the 13th century Rognosa tower in San Gimignano (Siena, Italy), the historic town inscribed on the Unesco World Heritage List in 1990. A structural nonlinear analysis of the tower has been performed via the freeware finite element code NOSA. The finite element mesh of the tower has been generated using a three-dimensional digital model of the tower and the surrounding buildings. The geometry data has been acquired by means of a time-of-flight laser scanner and then processed into the open source software MeshLab and other geometry processing tools. The behaviour of the tower, subjected to its own weight and time-dependent loads modelling the seismic excitations, has been investigated.Source: Tenth International Conference on Computational Structures Technology, Valencia, Spain, 14-17 September 2010

See at: CNR ExploRA Restricted | www.civil-comp.com Restricted


2010 Conference article Restricted

Numerical modelling of masonry towers: the case study of the "Rognosa" tower in San Gimignano
Girardi M., Padovani C., Pagni A., Pasquinelli G.
In this paper we present a preliminary study concerning the static behaviour and the seismic vulnerability of the "Rognosa" tower in San Gimignano, Italy, which was added to the Unesco World Heritage List in 1990. The structure is modelled by using the finite element code NOSA, in which the masonry is assumed to be a nonlinear elastic material with zero tensile strength and bounded compressive strength. The behaviour of the tower subjected to its own weight and an accelerogram recorded during a real earthquake, is investigated.Source: Advances and Trends in Structural Engineering, Mechanics and Computation. Fourth International Conference on Structural Engineering, Mechanics and Computation, pp. 993–996, Cape Town, South Africa, 6-8 Settembre 2010

See at: CNR ExploRA Restricted


2010 Report Closed Access

Analisi sismica di campanili e torri in muratura
Girardi M., Padovani C., Pagni A., Pasquinelli G.
Report of the project "Seismic analysis of masonry towers"Source: Project report, Analisi sismica di campanili e torri in muratura, 2010

See at: CNR ExploRA Restricted


2009 Conference article Restricted

Numerical modelling of the dynamic behaviour of masonry arches
Girardi M., Padovani C., Pagni A., Pasquinelli G.
The paper describes the results of analyses conducted by using the NOSA code on a circular masonry arch. The structure is subjected to its own weight and sinusoidal accelerations of variable frequency. The different results obtained using nonlinear and linear constitutive equations are compared.Source: Twelfth International Conference on Civil, Structural and Environmental Engineering Computing, Funchal, Madeira, Portugal, 1-4 Settembre 2009

See at: CNR ExploRA Restricted


2009 Contribution to conference Restricted

Modelli e strumenti di calcolo per l'analisi strutturale del patrimonio architettonico
Girardi M., Padovani C., Pagni A., Pasquinelli G.
Description of the activity carried out by the Mechanics of Materials and Structures Laboratory in the field of Cultural Heritage.Source: Salone dell'Arte e del Restauro di Firenze, Firenze - Stazione Leopolda, 29-31 ottobre 2009

See at: CNR ExploRA Restricted


2009 Contribution to conference Open Access OPEN

St@rt - Sviluppo di un sistema integrato per il rilievo 3D e l'analisi strutturale di costruzioni in muratura. Caso studio: la Torre "Rognosa" di San Gimignano, Siena
Callieri M., Corsini M., Girardi M., Padovani C., Pagni A., Pasquinelli G.
Source: Restauro - Salone dell'Arte del Restauro e della Conservazione dei Beni Culturali ed Ambientali, Ferrara, 2009

See at: ISTI Repository Open Access | CNR ExploRA


2009 Conference article Restricted

Thermo-mechanical solver for multi layer packages of power electronic devices and systems. Preliminary results
Bagnoli P. E., Girardi M., Padovani C., Pagni A., Pasquinelli G.
The DJOSER code has been tested as a useful and friendly tool for the thermal analysis of power electronic devices constituted by multilayer structures. The other problem connected with the packaging evaluation is the calculation of the thermally induced stresses and strains in the various layers of the assembling structures. This paper deals with the thermo-mechanical behaviour of 1-dimensional structures made up of layers with different geometrical and thermo-mechanical properties subjected to thermal loads. A first version of the thermo-mechanical solver connected with the DJOSER program has been implemented. The solver is able to calculate the stresses at the layer interfaces, using the same strategy of DJOSER, i.e. a semi-analytical mathematical approach, as well as the same structural models (stepped pyramidal structures, homogeneous layers). The basic theory is briefly exposed and the method is applied to a two-layers structure whose results are compared with those obtained using standard FEM analyses.Source: 27th UIT National Heat Transfer Conference. UIT09-041, pp. 225–230, Reggio Emilia, 22-24 June 2009

See at: CNR ExploRA Restricted


2009 Report Closed Access

A thermo-mechanical solver for multilayer power electronic assemblies integrated into the djoser thermal simulator
Bagnoli P. E., Padovani C., Pagni A., Pasquinelli G.
The DJOSER analytical thermal solver for multilayer mounting structures has been tested as a useful and friendly tool for the thermal analysis of power electronic devices and their packages, able to replace the onerous programs based on the finite element (FEM) calculations. The other problem connected with the packaging evaluation is the calculation of the thermally induced stresses and strains in the various layers composing the assembling structures. This paper deals with the first step of the implementation of a thermo-mechanical solver to be connected with the DJOSER program, which is able to calculate the stresses at the layer interfaces, using the same strategy, i.e. a semi-analytical mathematical approach, as well as the same structural models (stepped pyramidal structures, homogeneous layers). The basic theory is briefly exposed and the method is applied to some two-layers virtual structures. The obtained results are compared with those obtained using standard FEM analyses.Source: ISTI Technical reports, 2009

See at: CNR ExploRA Restricted


2009 Report Closed Access

Numerical modelling of masonry arches subjected to time-dependent loads
Girardi M., Padovani C., Pagni A., Pasquinelli G.
The paper describes the results of analyses conducted by using the NOSA code on a circular masonry arch. First the structure is subjected to its own weight and sinusoidal accelerations of variable frequency. Then, the behaviour of the arch subjected to an accelerogram recorded during a real earthquake is investigated. The different results obtained using nonlinear and linear constitutive equations are compared.Source: ISTI Technical reports, 2009

See at: CNR ExploRA Restricted


2009 Report Closed Access

Numerical methods for a class of nonlinear hyperbolic problems: a comparative study
Kharenko D., Padovani C., Pagni A., Pasquinelli G., Semin L.
In this paper we consider the problem of the free longitudinal vibrations of a beam made of a bimodular material, i.e. an elastic material whose in-tension Young's modulus is a fraction of that under compression. After recalling the exact solutions for an ifinite beam and for a beam with fixed ends calculated via the characteristics method, we apply high-resolution methods based on the finite-element approach to solve the nonliner equation of the motion. In particular, we compare the exact solutions with the numerical solutions calculated using the space-time element method, the collocation and least-squares method, as well as TVD and Newmark methods.Source: ISTI Technical reports, 2009

See at: CNR ExploRA Restricted


2009 Report Closed Access

Studio del comportamento termomeccanico di piastre multistrato
Girardi M., Padovani C., Pagni A., Pasquinelli G.
Questa ricerca è stata condotta dal Laboratorio di Meccanica dei Materiali e delle Strutture dell'ISTI-CNR nell'ambito del progetto "Studio del comportamento termo-meccanico di piastre multistrato" finanziato dalla Fondazione Cassa di Risparmio di Lucca (agosto 2008 - luglio 2009). Si è studiato il problema di equilibrio di una piastra costituita da più strati incollati tra loro, ciascuno dei quali è soggetto ad un assegnato carico termico, con lo scopo di determinare gli sforzi normali e tangenziali presenti alle interfacce dei vari strati. Limitandoci al caso monodimensionale, è stato quindi implementato il codice di calcolo PITER per l'integrazione delle equazioni integro differenziali ordinarie che governano il problema di equilibrio di ciascuno strato della struttura, tenendo conto delle condizioni al contorno, assegnate sulle superfici superiore ed inferiore della trave e delle condizioni di raccordo che garantiscono l'aderenza tra i vari strati.Source: Project report, Studio del comportamento termo-meccanico di piastre multistrato, 2009

See at: CNR ExploRA Restricted