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Papers by Francesco Potenza
Journal of Civil Structural Health Monitoring, 2015
The Open Construction and Building Technology Journal
In the cultural life of modern societies great importance has acquired the preservation of existi... more In the cultural life of modern societies great importance has acquired the preservation of existing and, in particular, ancient architectural heritage. With the inherent historical aspects, the economic implications have to be taken into account as well. Indeed, especially European cities and countries receive significant economic advantages by the existence of monuments and ancient suburbs. In this context, structural maintenance, strengthening and monitoring has gained an important academic and professional impulse. The present paper aims to present the results of a real-scale experimental work regarding the application of an innovative seismic retrofitting technique for masonry walls and vaults by Hydraulic Lime Mortar strengthened by Glass Fiber Reinforced Polymer textile grids (HLM-GFRP) embedding new sensing systems as fiber optical sensors. The real-scale specimen is a masonry polycentric pavilion vault that was damaged during the L’Aquila earthquake of April 2009. The need o...
Proceedings of the Eleventh International Conference on Civil, Structural and Environmental Engineering Computing, 2007
Encyclopedia of Earthquake Engineering, 2014
Structural identification based on experimental data coming from rapid and/or permanent monitorin... more Structural identification based on experimental data coming from rapid and/or permanent monitoring is continuously increasing its relevance in the process of the structural safety assessment. The paper discusses the direct and inverse problem of structures subjected to base excitation. Recent results in time domain modal identification are summarized for their relevance in the treatment of data coming from either rapid testing or permanent monitoring activities realized after the 2009 L'Aquila earthquake for two case studies. In the first one, the vibration measurements acquired in a two-day testing campaign on a damaged reinforced concrete building belonging to the Engineering Faculty of the University of L'Aquila have been used to directly compare the identified modal features with a modal model constructed by finite elements, representative of the structural behavior of the building in the early post-earthquake conditions. In the second one, the seismic response obtained through a permanent structural health monitoring system deployed on a monumental masonry building, the Basilica of S. Maria di Collemaggio, has been used to extract the modal parameters which compared with results coming by a finite element model, have furnished valuable information to evaluate the effectiveness of the temporary scaffolding structures. The study evidences that the reference-based combined deterministic-stochastic subspace identification of structures heavily damaged by earthquakes is a valuable tool to insight into noisy data acquired in difficult operational conditions. Finally, the specific technology developed along the research, for easy structural response measurements, is also presented, and its peculiar characteristics and drawbacks are finally discussed.
This work investigates the in-plane behaviour of a masonry building facade before and after struc... more This work investigates the in-plane behaviour of a masonry building facade before and after structural interventions with epoxy-based unidirectional FRP strips. To this end, a simple macro-modeling approach is proposed for the simulation of the XVIII century Camponeschi Palace facade in the city of L'Aquila, Italy, damaged by the 2009 earthquake. The FRP reinforcement of the facade is designed according to relevant guidelines and consists of vertical and horizontal FRP strips anchored to the masonry walls. In the numerical model, masonry and FRP are modeled according to a smeared crack approach and a truss-based approach, respectively. The assumption of perfect bonding between masonry and reinforcement is adopted in the work. Pushover analysis are carried out before and after strengthening. The real damage distribution over the facade was used for comparisons purposes. The effects of the FRP on the global behavior of the facade are presented and discussed.
Continuum Mechanics and Thermodynamics, 2015
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Ber... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
The paper approaches the multifaceted task of semiactively controlling the seismic response of a ... more The paper approaches the multifaceted task of semiactively controlling the seismic response of a prototypal building model, through interstorey bracings embedding magnetorheological dampers. The control strategy is based on a synthetic discrete model, purposely formulated in a reduced space of significant dynamic variables, and consistently updated to match the modal properties identified from the experimental response of the modeled physical
A method to design semi-active control strategies of asymmetric structures is presented. The meth... more A method to design semi-active control strategies of asymmetric structures is presented. The method is based on the optimal sizing of an equivalent Kelvin-Voight model describing the constitutive behavior of semi-active magneto-rheological devices, through the evaluation of the maximum achievable modal damping when they work in passive modality. The complex eigenvalue loci of the passively-controlled system versus the device mechanical characteristics are spanned for symmetric and asymmetric frame structures. A coherent representation of the reference effect ensured by an optimized linear active feedback on the eigenvalues loci is selected to drive the design of the adjustable properties of the semi-active device. A clipped-optimal control algorithm is used in a prototype experimental application whose performance are highlighted by the presented design method.
Journal of Sound and Vibration, 2013
a b s t r a c t A simple dynamic system composed of two linear oscillators is employed to analyze... more a b s t r a c t A simple dynamic system composed of two linear oscillators is employed to analyze the passive control performance that can be achieved through a visco-elastic damper connecting two adjacent free-standing structures. By extension, the model may also describe the energy dissipation which can be obtained by an internal coupling between two quasi-independent sub-systems composing a single complex structure. Two alternatives are evaluated for the linear coupling by considering either the serial or the parallel spring-dashpot arrangement known as the Kelvin-Voigt and the Maxwell damper model, which may synthetically reproduce the constitutive behavior of different industrial devices. The complex eigenvalues of the coupled system are parametrically analyzed to determine the potential benefits realized by different combinations of the coupling stiffness and damping coefficient. A design strategy to assess these parameters is outlined, driven by the relevant observation that a perfect tuning of the natural frequencies always corresponds, in the parameter space, to the maximum modal damping for one of the resonant modes, independent of the damper model. The effectiveness of the proposed strategy is discussed for different classes of the controlled system, depending on the mass and stiffness ratio of the component oscillators. As a major result, different design parameter charts for the two damper models are carried out and compared to each other. Performance indexes are introduced to quantitatively evaluate the passive control performance with respect to the mitigation of the system forced response under harmonic and seismic ground excitation. The analyses confirm the validity of the design strategy for a well-balanced mitigation of the displacement and acceleration response in both the oscillators.
![Research paper thumbnail of Corrigendum to “Damping performance of two simple oscillators coupled by a dissipative connection” [J. Sound Vibr. (2014) 2359–2377]](https://attachments.academia-assets.com/42613918/thumbnails/1.jpg)
](Journal of Sound and Vibration, 2014
Corrigendum to "Damping performance of two simple oscillators coupled by a dissipative connection" [
Journal of Performance of Constructed Facilities, 2013
The catastrophic earthquake that struck the city of L'Aquila in early April 2009 caused extensive... more The catastrophic earthquake that struck the city of L'Aquila in early April 2009 caused extensive damage to buildings at the University of L'Aquila. Among these edifices are those of the Engineering Faculty, which, in particular, suffered large structural displacements and accelerations that resulted in failures of nonstructural elements (infills, false ceilings, door and window frames), the breakage of wiring and piping systems, and the destruction of furniture and machinery. Of these buildings, the so-called Edifice A presents the most critical damage scenario, requiring a significant rehabilitating intervention. The structural behavior of this building, composed of seven independent RC substructures, is the object of intensive investigation; this is in part because irregularities among these substructures, in terms of geometry, stiffness, and weight distribution, provide a rich case study for interpreting different structural and nonstructural damage scenarios. The paper interprets the observed damage through use of incremental analyses for evaluation of the threshold between linear and nonlinear structural behavior. For this purpose, several finite-element (FE) models are developed with increasing complexity in the geometry and the shear-wall modeling. Capacity curves obtained by the nonlinear pushover analyses are afterward compared with the perceived seismic demands of the structures including site effects. Moreover, based on simplified analyses, numerical evaluations of acceleration-producing failures in the infill walls and the split-face brick walls were performed to achieve an overall description of the structural and nonstructural damage.
Earthquake Engineering and Engineering Vibration, 2009
Theoretical and practical issues concerning the multi-faceted task of mitigating the latero-torsi... more Theoretical and practical issues concerning the multi-faceted task of mitigating the latero-torsional seismic response of a prototypal frame structure with asymmetric mass distribution are approached. Chevron braces with embedded magnetorheological dampers acting on the interstory drift are used to ensure additional energy dissipation. The semi-active control strategy employed to govern the modifi cation of the damper characteristics via feedback is based on the selection of optimal forces according to a H 2 /LQG criterion, with respect to which the actual forces are regulated by a clipped-optimal logic. A dynamic observer is used to estimate the state through a non-collocated placement of the acceleration sensors. Several aspects to be addressed throughout the complex process including the design, modelization, and implementation phases of semi-active protection systems are discussed. Finally, experimental results obtained to mitigate the motion induced by ground excitation in a large-scale laboratory prototype, simulating the seismic response of a two-story building, are summarized.
Journal of Civil Structural Health Monitoring, 2015
The Open Construction and Building Technology Journal
In the cultural life of modern societies great importance has acquired the preservation of existi... more In the cultural life of modern societies great importance has acquired the preservation of existing and, in particular, ancient architectural heritage. With the inherent historical aspects, the economic implications have to be taken into account as well. Indeed, especially European cities and countries receive significant economic advantages by the existence of monuments and ancient suburbs. In this context, structural maintenance, strengthening and monitoring has gained an important academic and professional impulse. The present paper aims to present the results of a real-scale experimental work regarding the application of an innovative seismic retrofitting technique for masonry walls and vaults by Hydraulic Lime Mortar strengthened by Glass Fiber Reinforced Polymer textile grids (HLM-GFRP) embedding new sensing systems as fiber optical sensors. The real-scale specimen is a masonry polycentric pavilion vault that was damaged during the L’Aquila earthquake of April 2009. The need o...
Proceedings of the Eleventh International Conference on Civil, Structural and Environmental Engineering Computing, 2007
Encyclopedia of Earthquake Engineering, 2014
Structural identification based on experimental data coming from rapid and/or permanent monitorin... more Structural identification based on experimental data coming from rapid and/or permanent monitoring is continuously increasing its relevance in the process of the structural safety assessment. The paper discusses the direct and inverse problem of structures subjected to base excitation. Recent results in time domain modal identification are summarized for their relevance in the treatment of data coming from either rapid testing or permanent monitoring activities realized after the 2009 L'Aquila earthquake for two case studies. In the first one, the vibration measurements acquired in a two-day testing campaign on a damaged reinforced concrete building belonging to the Engineering Faculty of the University of L'Aquila have been used to directly compare the identified modal features with a modal model constructed by finite elements, representative of the structural behavior of the building in the early post-earthquake conditions. In the second one, the seismic response obtained through a permanent structural health monitoring system deployed on a monumental masonry building, the Basilica of S. Maria di Collemaggio, has been used to extract the modal parameters which compared with results coming by a finite element model, have furnished valuable information to evaluate the effectiveness of the temporary scaffolding structures. The study evidences that the reference-based combined deterministic-stochastic subspace identification of structures heavily damaged by earthquakes is a valuable tool to insight into noisy data acquired in difficult operational conditions. Finally, the specific technology developed along the research, for easy structural response measurements, is also presented, and its peculiar characteristics and drawbacks are finally discussed.
This work investigates the in-plane behaviour of a masonry building facade before and after struc... more This work investigates the in-plane behaviour of a masonry building facade before and after structural interventions with epoxy-based unidirectional FRP strips. To this end, a simple macro-modeling approach is proposed for the simulation of the XVIII century Camponeschi Palace facade in the city of L'Aquila, Italy, damaged by the 2009 earthquake. The FRP reinforcement of the facade is designed according to relevant guidelines and consists of vertical and horizontal FRP strips anchored to the masonry walls. In the numerical model, masonry and FRP are modeled according to a smeared crack approach and a truss-based approach, respectively. The assumption of perfect bonding between masonry and reinforcement is adopted in the work. Pushover analysis are carried out before and after strengthening. The real damage distribution over the facade was used for comparisons purposes. The effects of the FRP on the global behavior of the facade are presented and discussed.
Continuum Mechanics and Thermodynamics, 2015
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Ber... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
The paper approaches the multifaceted task of semiactively controlling the seismic response of a ... more The paper approaches the multifaceted task of semiactively controlling the seismic response of a prototypal building model, through interstorey bracings embedding magnetorheological dampers. The control strategy is based on a synthetic discrete model, purposely formulated in a reduced space of significant dynamic variables, and consistently updated to match the modal properties identified from the experimental response of the modeled physical
A method to design semi-active control strategies of asymmetric structures is presented. The meth... more A method to design semi-active control strategies of asymmetric structures is presented. The method is based on the optimal sizing of an equivalent Kelvin-Voight model describing the constitutive behavior of semi-active magneto-rheological devices, through the evaluation of the maximum achievable modal damping when they work in passive modality. The complex eigenvalue loci of the passively-controlled system versus the device mechanical characteristics are spanned for symmetric and asymmetric frame structures. A coherent representation of the reference effect ensured by an optimized linear active feedback on the eigenvalues loci is selected to drive the design of the adjustable properties of the semi-active device. A clipped-optimal control algorithm is used in a prototype experimental application whose performance are highlighted by the presented design method.
Journal of Sound and Vibration, 2013
a b s t r a c t A simple dynamic system composed of two linear oscillators is employed to analyze... more a b s t r a c t A simple dynamic system composed of two linear oscillators is employed to analyze the passive control performance that can be achieved through a visco-elastic damper connecting two adjacent free-standing structures. By extension, the model may also describe the energy dissipation which can be obtained by an internal coupling between two quasi-independent sub-systems composing a single complex structure. Two alternatives are evaluated for the linear coupling by considering either the serial or the parallel spring-dashpot arrangement known as the Kelvin-Voigt and the Maxwell damper model, which may synthetically reproduce the constitutive behavior of different industrial devices. The complex eigenvalues of the coupled system are parametrically analyzed to determine the potential benefits realized by different combinations of the coupling stiffness and damping coefficient. A design strategy to assess these parameters is outlined, driven by the relevant observation that a perfect tuning of the natural frequencies always corresponds, in the parameter space, to the maximum modal damping for one of the resonant modes, independent of the damper model. The effectiveness of the proposed strategy is discussed for different classes of the controlled system, depending on the mass and stiffness ratio of the component oscillators. As a major result, different design parameter charts for the two damper models are carried out and compared to each other. Performance indexes are introduced to quantitatively evaluate the passive control performance with respect to the mitigation of the system forced response under harmonic and seismic ground excitation. The analyses confirm the validity of the design strategy for a well-balanced mitigation of the displacement and acceleration response in both the oscillators.
Journal of Sound and Vibration, 2014
Corrigendum to "Damping performance of two simple oscillators coupled by a dissipative connection" [
Journal of Performance of Constructed Facilities, 2013
The catastrophic earthquake that struck the city of L'Aquila in early April 2009 caused extensive... more The catastrophic earthquake that struck the city of L'Aquila in early April 2009 caused extensive damage to buildings at the University of L'Aquila. Among these edifices are those of the Engineering Faculty, which, in particular, suffered large structural displacements and accelerations that resulted in failures of nonstructural elements (infills, false ceilings, door and window frames), the breakage of wiring and piping systems, and the destruction of furniture and machinery. Of these buildings, the so-called Edifice A presents the most critical damage scenario, requiring a significant rehabilitating intervention. The structural behavior of this building, composed of seven independent RC substructures, is the object of intensive investigation; this is in part because irregularities among these substructures, in terms of geometry, stiffness, and weight distribution, provide a rich case study for interpreting different structural and nonstructural damage scenarios. The paper interprets the observed damage through use of incremental analyses for evaluation of the threshold between linear and nonlinear structural behavior. For this purpose, several finite-element (FE) models are developed with increasing complexity in the geometry and the shear-wall modeling. Capacity curves obtained by the nonlinear pushover analyses are afterward compared with the perceived seismic demands of the structures including site effects. Moreover, based on simplified analyses, numerical evaluations of acceleration-producing failures in the infill walls and the split-face brick walls were performed to achieve an overall description of the structural and nonstructural damage.
Earthquake Engineering and Engineering Vibration, 2009
Theoretical and practical issues concerning the multi-faceted task of mitigating the latero-torsi... more Theoretical and practical issues concerning the multi-faceted task of mitigating the latero-torsional seismic response of a prototypal frame structure with asymmetric mass distribution are approached. Chevron braces with embedded magnetorheological dampers acting on the interstory drift are used to ensure additional energy dissipation. The semi-active control strategy employed to govern the modifi cation of the damper characteristics via feedback is based on the selection of optimal forces according to a H 2 /LQG criterion, with respect to which the actual forces are regulated by a clipped-optimal logic. A dynamic observer is used to estimate the state through a non-collocated placement of the acceleration sensors. Several aspects to be addressed throughout the complex process including the design, modelization, and implementation phases of semi-active protection systems are discussed. Finally, experimental results obtained to mitigate the motion induced by ground excitation in a large-scale laboratory prototype, simulating the seismic response of a two-story building, are summarized.