Luca Salvatori | Università degli Studi di Firenze (University of Florence) (original) (raw)

Papers by Luca Salvatori

Research paper thumbnail of Super long span bridges: wind-resistant design developments and open issues

Proceedings of the Institution of Civil Engineers, Nov 26, 2023

Research paper thumbnail of Forming New Openings in Load-Bearing Masonry Walls: Design Methods and Nonlinear Finite Element Simulations

Research paper thumbnail of Probabilistic seismic-damage of masonry towers

Research paper thumbnail of Down-Aisle Seismic Behavior of Pallet-Rack Systems: Experimental Tests and Numerical Analyses

Research paper thumbnail of Large suspension bridges to withstand wind loading

Research paper thumbnail of Preliminary Assessment Of The Seismic Behaviour Of Giotto’s Bell Tower In Florence

International Journal of Architectural Heritage, Dec 7, 2022

Research paper thumbnail of Stefan Problem through Extended Finite Elements: Review and Further Investigations

Algorithms, Sep 21, 2009

A general review of the extended finite element method and its application to the simulation of f... more A general review of the extended finite element method and its application to the simulation of first-order phase transitions is provided. Detailed numerical investigations are then performed by focusing on the one-dimensional case and studying: (i) spatial and temporal discretisations, (ii) different numerical techniques for the interface-condition enforcement, and (iii) different treatments for the blending elements. An embeddeddiscontinuity finite element approach is also developed and compared with the extended finite element method, so that a clearer insight of the latter can be given. Numerical examples for melting/solidification in planar, cylindrical, and spherical symmetry are presented and the results are compared with analytical solutions.

Research paper thumbnail of Frequency- and time-domain methods for the numerical modeling of full-bridge aeroelasticity

Computers & Structures, Jun 1, 2007

A numerical framework for full-bridge aeroelasticity is presented, based on unsteady cross-sectio... more A numerical framework for full-bridge aeroelasticity is presented, based on unsteady cross-sectional load models and on the finite-element modeling of the structure. A frequency-domain approach based on aeroelastic derivatives and nonlinear complex eigenvalue ...

Research paper thumbnail of A discrete 3D model for bridge aerodynamics and aeroelasticity: nonlinearities and linearizations

Meccanica, Dec 6, 2006

A framework for the numerical analysis of bridges under wind excitation is outlined. It is based ... more A framework for the numerical analysis of bridges under wind excitation is outlined. It is based on structural finite element scheme and cross-sectional wind load models. Two aspects are investigated: (1) how considering the mean steady configuration in the aerodynamic stability calculation; and (2) the effects of load nonlinearities on structural response. A quasi-steady load model is adopted, which is able to deal with the considered problems by using experimental data easily available in the practice. By means of numerical examples, it is pointed out (1) that both the modifications in structural tangential stiffness and in the aerodynamic coefficients due to the mean steady deformation may affect the aeroelastic stability threshold and (2) that load linearization may produce an underestimation of the structural response.

Research paper thumbnail of Experimental, numerical, and regulatory P-M-M domains for cold-formed perforated steel uprights of pallet-racks

Thin-walled Structures, Oct 1, 2017

Abstract The results of an extensive experimental campaign on centric and eccentric compressive b... more Abstract The results of an extensive experimental campaign on centric and eccentric compressive behavior of thin-walled steel uprights of pallet-rack systems are presented. The analyzed cold-formed profiles are perforated through their whole length and have open, mono-symmetric cross-sections. Experimental results are extended through finite-element simulations, including geometrical and material nonlinearities, to obtain detailed three-dimensional compression-bending-bending strength-domains, which are compared to building-code prescriptions. Regulations are safety preserving, with an average difference of about 10%, and maximum difference for bending about the weak axis. Unlike in regulatory prescriptions, the experimental-numerical results show unsymmetrical behavior about the weak axis and nonlinear, convex bending-bending interaction.

Research paper thumbnail of Effects of structural nonlinearity and along-span wind coherence on suspension bridge aerodynamics: Some numerical simulation results

Journal of Wind Engineering and Industrial Aerodynamics, May 1, 2006

The response of suspension bridges to wind excitation is studied by means of numerical simulation... more The response of suspension bridges to wind excitation is studied by means of numerical simulations with a specifically developed finite element program implementing full structural nonlinearities. A pure time-domain load model, linearized around the average ...

Research paper thumbnail of Probabilistic seismic performance of masonry towers: General procedure and a simplified implementation

Engineering Structures, Jul 1, 2015

A procedure for the probabilistic assessment of the seismic performance of masonry towers is deve... more A procedure for the probabilistic assessment of the seismic performance of masonry towers is developed within the general PEER framework. The ingredients identified for the whole procedure are the Intensity Measure (IM), the mechanical model, the seismic procedure, the Engineering Demand Parameter (EDP), the uncertain mechanical parameters, and the probabilistic method. For each one, a choice suitable for masonry towers is proposed. A tower is modeled as a geometrically nonlinear Timoshenko beam with no-tensile and limited-compressive strengths. The reaching of the ultimate compressive strain is assumed as main failure criterion. Pushover analyses are carried out and a performance measure based on the seismic displacement capacity and demand is used as EDP. The conditional probability of exceedance of the EDP given the peak bedrock acceleration, used as IM, is computed through Monte Carlo simulations by considering as random variables the mechanical parameters representative of inertia, stiffness, strength, and ductility of the masonry. The calculations are then developed with reference to a case study. The dispersion of the displacement capacity is recognized as the main source of uncertainty. As to the mechanical parameters, the compressive strength and the strain ductility play the most critical roles, as also highlighted by a sensitivity analysis. These parameters are the most uncertain as destructive tests, usually not allowed in historical monumental buildings, would be required for their assessment. The effects of static load patterns for nonlinear static analysis and the comparison with incremental dynamic analysis are also briefly discussed.

Research paper thumbnail of On the seismic response of rack structures affected by pinching

Procedia structural integrity, 2023

Research paper thumbnail of In-Plane Seismic Response of Masonry Walls through a Hybrid Continuum-Discrete Multiscale Model

Research paper thumbnail of Role of correlation between mechanical parameters in the probabilistic seismic vulnerability of historical masonry towers

Research paper thumbnail of Nonlinear Static and Incremental Dynamic Analyses for Seismic Down-Aisle Behavior of Rack Structures

Research paper thumbnail of Some recent developments in FE-modelling of cracking in concrete and quasi-brittle materials

Modelling concrete continuum models, namely a single parameter isotropic damage model (SDM) and a... more Modelling concrete continuum models, namely a single parameter isotropic damage model (SDM) and a rotating crack model (RCM), are analysed, developed and implemented into an existing modular computer program (FEMAS, Finite Element Modulus of Arbitrary Structures, Ruhr-Universität Bochum, Germany). These models are of interest not only for concrete but also for other-so-called quasi-brittle-materials (such as masonry, rocks and some kind of soils), which are frequently used by civil engineers. 3. PHYSICAL PARAMETERS CHARACTERIZING TENSIONAL CRACKING Cracking and consequent loss of mechanical properties occur due to the proliferation and the coalescence of micro-defects and micro-voids, which exist in concrete even before the application of any external action.

Research paper thumbnail of Hybrid discrete-continuum multiscale modelling of masonry walls

Research paper thumbnail of Frequency- versus Time- Domain Methods for the Numerical Modelling of Bridge Aeroelasticity

Research paper thumbnail of Assessment and Mitigation of Wind Risk of Suspended-Span Bridges

I wish to thank Prof. Claudio Borri and Prof. Udo Peil for their advice and tutoring activity. My... more I wish to thank Prof. Claudio Borri and Prof. Udo Peil for their advice and tutoring activity. My gratitude goes to Prof. Paolo Spinelli for his suggestions and support, and to Prof. Paolo Maria Mariano for his encouragement and for being a constant example of dedication to research and teaching. Special thanks to Prof. Wolfhard Zahlten, who co-tutored this work, Dr. Renato Eusani, and Dr.-cand. Christian Neuhaus for the scientific discussions, the exchange of ideas and data, and their warm welcome to the University of Wuppertal at the beginning of my doctoral experience. The discussions with Prof. Gianni Bartoli, Dr. Carlotta Costa, Dr. Claudio Mannini, and Dr. Stefano Pastò are gratefully acknowledged. I am thankful to Prof. Luca Facchini for sharing his competence on windfield generations, Prof. Herman G. Matthies for welcoming me at the Course on Nonlinear Computational Mechanics in Braunschweig, and Prof. Masaru Matsumoto for the experimental data he kindly sent me. Finally, thanks to my friend Carlo Salinari for proofreading part of this work, to Dr.-cand. Nadine Kimme for helping me with the German translation of the abstract, and to Dr.-cand. Anna Bosi and Dr.-cand. Emanuele Marfisi for their encouragement and counsel.

Research paper thumbnail of Super long span bridges: wind-resistant design developments and open issues

Proceedings of the Institution of Civil Engineers, Nov 26, 2023

Research paper thumbnail of Forming New Openings in Load-Bearing Masonry Walls: Design Methods and Nonlinear Finite Element Simulations

Research paper thumbnail of Probabilistic seismic-damage of masonry towers

Research paper thumbnail of Down-Aisle Seismic Behavior of Pallet-Rack Systems: Experimental Tests and Numerical Analyses

Research paper thumbnail of Large suspension bridges to withstand wind loading

Research paper thumbnail of Preliminary Assessment Of The Seismic Behaviour Of Giotto’s Bell Tower In Florence

International Journal of Architectural Heritage, Dec 7, 2022

Research paper thumbnail of Stefan Problem through Extended Finite Elements: Review and Further Investigations

Algorithms, Sep 21, 2009

A general review of the extended finite element method and its application to the simulation of f... more A general review of the extended finite element method and its application to the simulation of first-order phase transitions is provided. Detailed numerical investigations are then performed by focusing on the one-dimensional case and studying: (i) spatial and temporal discretisations, (ii) different numerical techniques for the interface-condition enforcement, and (iii) different treatments for the blending elements. An embeddeddiscontinuity finite element approach is also developed and compared with the extended finite element method, so that a clearer insight of the latter can be given. Numerical examples for melting/solidification in planar, cylindrical, and spherical symmetry are presented and the results are compared with analytical solutions.

Research paper thumbnail of Frequency- and time-domain methods for the numerical modeling of full-bridge aeroelasticity

Computers & Structures, Jun 1, 2007

A numerical framework for full-bridge aeroelasticity is presented, based on unsteady cross-sectio... more A numerical framework for full-bridge aeroelasticity is presented, based on unsteady cross-sectional load models and on the finite-element modeling of the structure. A frequency-domain approach based on aeroelastic derivatives and nonlinear complex eigenvalue ...

Research paper thumbnail of A discrete 3D model for bridge aerodynamics and aeroelasticity: nonlinearities and linearizations

Meccanica, Dec 6, 2006

A framework for the numerical analysis of bridges under wind excitation is outlined. It is based ... more A framework for the numerical analysis of bridges under wind excitation is outlined. It is based on structural finite element scheme and cross-sectional wind load models. Two aspects are investigated: (1) how considering the mean steady configuration in the aerodynamic stability calculation; and (2) the effects of load nonlinearities on structural response. A quasi-steady load model is adopted, which is able to deal with the considered problems by using experimental data easily available in the practice. By means of numerical examples, it is pointed out (1) that both the modifications in structural tangential stiffness and in the aerodynamic coefficients due to the mean steady deformation may affect the aeroelastic stability threshold and (2) that load linearization may produce an underestimation of the structural response.

Research paper thumbnail of Experimental, numerical, and regulatory P-M-M domains for cold-formed perforated steel uprights of pallet-racks

Thin-walled Structures, Oct 1, 2017

Abstract The results of an extensive experimental campaign on centric and eccentric compressive b... more Abstract The results of an extensive experimental campaign on centric and eccentric compressive behavior of thin-walled steel uprights of pallet-rack systems are presented. The analyzed cold-formed profiles are perforated through their whole length and have open, mono-symmetric cross-sections. Experimental results are extended through finite-element simulations, including geometrical and material nonlinearities, to obtain detailed three-dimensional compression-bending-bending strength-domains, which are compared to building-code prescriptions. Regulations are safety preserving, with an average difference of about 10%, and maximum difference for bending about the weak axis. Unlike in regulatory prescriptions, the experimental-numerical results show unsymmetrical behavior about the weak axis and nonlinear, convex bending-bending interaction.

Research paper thumbnail of Effects of structural nonlinearity and along-span wind coherence on suspension bridge aerodynamics: Some numerical simulation results

Journal of Wind Engineering and Industrial Aerodynamics, May 1, 2006

The response of suspension bridges to wind excitation is studied by means of numerical simulation... more The response of suspension bridges to wind excitation is studied by means of numerical simulations with a specifically developed finite element program implementing full structural nonlinearities. A pure time-domain load model, linearized around the average ...

Research paper thumbnail of Probabilistic seismic performance of masonry towers: General procedure and a simplified implementation

Engineering Structures, Jul 1, 2015

A procedure for the probabilistic assessment of the seismic performance of masonry towers is deve... more A procedure for the probabilistic assessment of the seismic performance of masonry towers is developed within the general PEER framework. The ingredients identified for the whole procedure are the Intensity Measure (IM), the mechanical model, the seismic procedure, the Engineering Demand Parameter (EDP), the uncertain mechanical parameters, and the probabilistic method. For each one, a choice suitable for masonry towers is proposed. A tower is modeled as a geometrically nonlinear Timoshenko beam with no-tensile and limited-compressive strengths. The reaching of the ultimate compressive strain is assumed as main failure criterion. Pushover analyses are carried out and a performance measure based on the seismic displacement capacity and demand is used as EDP. The conditional probability of exceedance of the EDP given the peak bedrock acceleration, used as IM, is computed through Monte Carlo simulations by considering as random variables the mechanical parameters representative of inertia, stiffness, strength, and ductility of the masonry. The calculations are then developed with reference to a case study. The dispersion of the displacement capacity is recognized as the main source of uncertainty. As to the mechanical parameters, the compressive strength and the strain ductility play the most critical roles, as also highlighted by a sensitivity analysis. These parameters are the most uncertain as destructive tests, usually not allowed in historical monumental buildings, would be required for their assessment. The effects of static load patterns for nonlinear static analysis and the comparison with incremental dynamic analysis are also briefly discussed.

Research paper thumbnail of On the seismic response of rack structures affected by pinching

Procedia structural integrity, 2023

Research paper thumbnail of In-Plane Seismic Response of Masonry Walls through a Hybrid Continuum-Discrete Multiscale Model

Research paper thumbnail of Role of correlation between mechanical parameters in the probabilistic seismic vulnerability of historical masonry towers

Research paper thumbnail of Nonlinear Static and Incremental Dynamic Analyses for Seismic Down-Aisle Behavior of Rack Structures

Research paper thumbnail of Some recent developments in FE-modelling of cracking in concrete and quasi-brittle materials

Modelling concrete continuum models, namely a single parameter isotropic damage model (SDM) and a... more Modelling concrete continuum models, namely a single parameter isotropic damage model (SDM) and a rotating crack model (RCM), are analysed, developed and implemented into an existing modular computer program (FEMAS, Finite Element Modulus of Arbitrary Structures, Ruhr-Universität Bochum, Germany). These models are of interest not only for concrete but also for other-so-called quasi-brittle-materials (such as masonry, rocks and some kind of soils), which are frequently used by civil engineers. 3. PHYSICAL PARAMETERS CHARACTERIZING TENSIONAL CRACKING Cracking and consequent loss of mechanical properties occur due to the proliferation and the coalescence of micro-defects and micro-voids, which exist in concrete even before the application of any external action.

Research paper thumbnail of Hybrid discrete-continuum multiscale modelling of masonry walls

Research paper thumbnail of Frequency- versus Time- Domain Methods for the Numerical Modelling of Bridge Aeroelasticity

Research paper thumbnail of Assessment and Mitigation of Wind Risk of Suspended-Span Bridges

I wish to thank Prof. Claudio Borri and Prof. Udo Peil for their advice and tutoring activity. My... more I wish to thank Prof. Claudio Borri and Prof. Udo Peil for their advice and tutoring activity. My gratitude goes to Prof. Paolo Spinelli for his suggestions and support, and to Prof. Paolo Maria Mariano for his encouragement and for being a constant example of dedication to research and teaching. Special thanks to Prof. Wolfhard Zahlten, who co-tutored this work, Dr. Renato Eusani, and Dr.-cand. Christian Neuhaus for the scientific discussions, the exchange of ideas and data, and their warm welcome to the University of Wuppertal at the beginning of my doctoral experience. The discussions with Prof. Gianni Bartoli, Dr. Carlotta Costa, Dr. Claudio Mannini, and Dr. Stefano Pastò are gratefully acknowledged. I am thankful to Prof. Luca Facchini for sharing his competence on windfield generations, Prof. Herman G. Matthies for welcoming me at the Course on Nonlinear Computational Mechanics in Braunschweig, and Prof. Masaru Matsumoto for the experimental data he kindly sent me. Finally, thanks to my friend Carlo Salinari for proofreading part of this work, to Dr.-cand. Nadine Kimme for helping me with the German translation of the abstract, and to Dr.-cand. Anna Bosi and Dr.-cand. Emanuele Marfisi for their encouragement and counsel.