Presentations by Francesco Petrini
This mini-symposium provides the opportunity to present current research efforts and findings in ... more This mini-symposium provides the opportunity to present current research efforts and findings in the context of performance-based, reliability-based, and risk-based design of engineering systems subjected to natural and man-made hazards. Contributions addressing both theoretical developments and practical applications from different sub-fields of structural engineering (e.g., earthquake, wind, hurricane, fire, offshore, aerospace, blast engineering) are welcome Mitigation of natural and man-made hazards is one of the major goals of structural engineering. In the last few decades, several methodologies have been developed and/or formalized to achieve this aim, e.g., performance-based design, reliability-based design, and risk-based design. While these approaches have different focuses, they have in common the explicit and rational consideration of the uncertainties that inherently affect loading environment, mechanical properties of structural materials, boundary conditions, modeling assumptions, construction procedures, and other relevant types of aleatory and epistemic uncertainties. In addition, formally different approaches can be used in combined frameworks, e.g., reliability-based optimization in the context of performance-based earthquake engineering.
Papers by Francesco Petrini
Wind Energy, 2020
This paper presents an optimal design procedure for a pendulum tuned mass damper (PTMD) to mitiga... more This paper presents an optimal design procedure for a pendulum tuned mass damper (PTMD) to mitigate the global structural vibrations of offshore wind turbines (OWTs) in the fore-aft and side-side directions. The procedure is tested to the design of a PTMD to be applied to the 5-MW benchmark baseline monopile wind turbine proposed by the National Renewable Energy Lab (NREL). The computation of wind and wave spectra, as well as the evaluation of the hydrodynamic and aerodynamic loads, is conducted by using an in-house built MATLAB® routine working together with an ANSYS® 3-D finite element (FE) global model for evaluating the resultant peak displacement response at the OWT hub by a power spectral density (PSD) analysis. In order to validate the OWT FEM model, a result comparison is made with the NREL OpenFAST, finding good matches between the two codes. An in-house built genetic algorithm (GA) toolbox, coded in MATLAB®, is then used to optimally design the parameters of a PTMD with a simplified 2-degrees-of-freedom (2DOF) model. The chosen GA fitness function targets the minimization of the peak response of the primary structure as evaluated by the 2DOF model. The design parameters of the PTMD are the flexural rigidity and damping, the mass ratio and pendulum length. After the 3-D FE model of the OWT without any control device has been validated, and the PTMD has been optimized by the simplified 2DOF model, the performances of the PTMD are examined on a 3-D global FE OWT + PTMD model in ANSYS®.
Structural Engineering and Mechanics, 2019
Long-span steel suspension bridges develop significant vibrations under the effect of external ti... more Long-span steel suspension bridges develop significant vibrations under the effect of external time-variable loadings because their slenderness. This causes significant stresses variations that could induce fatigue problems in critical components of the bridge. The research outcome presented in this paper includes a fatigue analysis of a long suspension bridge with 3300 meters central suspended span under wind action and train transit. Special focus is made on the counterintuitive interaction effects between train and wind loads in terms of fatigue damage accumulation in the hanger ropes. In fact the coupling of the two actions is shown to have positive effects for some hangers in terms of damage accumulation. Fatigue damage is evaluated using a linear accumulation model (Palmgren-Miner rule), analyses are carried out in time domain by a three-dimensional non-linear finite element model of the bridge. Rational explanation regarding the above-mentioned counterintuitive behavior is given on the basis of the stress time histories obtained for pertinent hangers under the effects of wind and train as acting separately or simultaneously. The interaction between wind and train traffic loads can be critical for a some hanger ropes therefore interaction phenomena within loads should be considered in the design.
PhD PROGRAM IN STRUCTURAL AND GEOTECHNICAL ENGINEERING
DOTTORATO DI RICERCA IN INGEGNERIA STRUT... more PhD PROGRAM IN STRUCTURAL AND GEOTECHNICAL ENGINEERING
DOTTORATO DI RICERCA IN INGEGNERIA STRUTTURALE E GEOTECNICA
Department of Structural and Geotechnical Engineering
Dipartimento di Ingegneria Strutturale e Geotecnica
DESIGN OF WIND-EXCITED CIVIL STRUCTURES:
PHENOMENOLOGICAL BASIS, PERFORMANCES ASSESSMENT, SOLUTIONS AND CASE STUDIES
What does the proper design of wind-excited civil structures need? What is the research practice in Wind Engineering today? How can we imagine tomorrow solutions for today open issues? The PhD course aims at providing some partial responses to the questions above, by lectures, seminars and brainstorming. Teaching lectures on established research and practice. The design of wind-excited Civil Structures needs, among others, sound phenomenological background in aerodynamics and aeroelasticity to set the problem, conceptual design abilities to solve the problem, analysis tools to assess the performance of candidate solutions. Teaching lectures select well-established fundamentals in Wind Engineering about the above issues. Seminars on current research. Additional seminars are focused on recent advances on selected topics in Wind Engineering. A view of research methods, as well as goals and achievements of selected research projects in the field. Brainstorming on research frontiers. As a closing loop step, brainstorming sessions are intended to seed some doubts and shed some light on open issues in Wind Engineering. Open minded, informal discussions towards potential step changes with respect to the current state of practice and knowledge. TARGET AUDIENCE: PhD students (main), Post-doctoral fellows (secondary), Researchers, Engineers, from both Italy and abroad. LAYOUT OF THE COURSE: • 3 days (8+8+4 hours), 20 hours in total • First two days: 6 hours of teaching lectures on established research and practice + 1 hours of seminars on current research + 1 hour of brainstorming on research frontiers • Third day: 4 hours of lectures on established research and practice
The aim of this paper is to investigate the role of damage and loss analysis in the Performance-B... more The aim of this paper is to investigate the role of damage and loss analysis in the Performance-Based Wind Engineering. The loss of structural serviceability under the action of wind is not rare, especially for high-rise buildings (lack of comfort for building residents) and for suspension bridges (temporary closure of the bridge to the users). In these cases, the damage and loss evaluations are not trivial and are very poorly investigated in literature. Starting from a literature review damage and loss analysis for wind, and on the basis of critical analysis and synthesis, a conceptual framework is presented for the consideration of these issues, not only for the safety, but also for the serviceability assessment of structures.
Proceedings of the 2011 …, Jan 1, 2011
Offshore wind turbines are complex structural and mechanical systems located in a highly demandin... more Offshore wind turbines are complex structural and mechanical systems located in a highly demanding environment. This paper proposes a multi-level system approach for studying the structural behavior of the support structure of an offshore wind turbine. In accordance with this approach, a proper numerical modeling requires the adoption of a suitable technique in order to organize the qualitative and quantitative assessment in various sub-problems, which can be solved by means of sub-models at different levels of detail, both for the structural behavior and for the simulation of loads. Consequently, in a first place, the effects on the structural response induced by the uncertainty of the parameters used to describe the environmental actions and the finite element model of the structure are inquired. After that, a mesolevel FEM model of the blade is adopted in order to obtain the detailed load stress on the blade/hub connection.
Volume 10: Mechanical Systems and Control, Parts A and B, 2009
The most rational way of assessing and reducing the risks of building constructions and infrastru... more The most rational way of assessing and reducing the risks of building constructions and infrastructures subject to natural and man-made hazards is Performance-Based Design, usually indicated by the acronym PBD; this applies to both design of new facilities and rehabilitation or retrofitting of the existing ones. The basic concept of PBD has been applied for almost 30 years in the nuclear power plant industry; later, PBD has been formalized and developed primarily in seismic engineering but has been extended to other engineering ...
Proceedings of the Workshop on Reliability and Optimization of Structural Systems IFIP WG, Aug 6, 2008
Proceedings of Fifth European and African Conference on Wind Engineering, Florence, Italy, 2009
It is widely recognized that the most rational way of tackling the risks of engineered facilities... more It is widely recognized that the most rational way of tackling the risks of engineered facilities and infrastructures subject to natural and man-made phenomena, and reducing them, both in designing new facilities and in rehabilitating or retrofitting the existing ones, is Performance-Based Design, usually indicated by the acronym PBD (but a better term would be “Performance-Based Engineering”). The basic concepts of PBD have been applied for almost 30 years in the nuclear power plant industry; later, PBD has been ...
ABSTRACT Accidental actions which may affect the offshore topsides structure during its design li... more ABSTRACT Accidental actions which may affect the offshore topsides structure during its design life shall be identified and assessed by means of hazard analysis. The structural system shall be designed to resist accidental actions so as to ensure the main safety functions of the structure are not so impaired as to lead to either unacceptable loss of integrity of the structure or escalation to cause its partial collapse.
ABSTRACT The modern design philosophy known as the performance-based design has earned the attent... more ABSTRACT The modern design philosophy known as the performance-based design has earned the attention of the scientific community over the last two decades, especially in the fields of earthquake and fire engineering. Its general scheme entails the evaluation of the probability distribution of a decision variable, usually represented by an economic index.
In many typical R.C. applications, the reinforcing bars along certain alignments must be maintain... more In many typical R.C. applications, the reinforcing bars along certain alignments must be maintained continuous. Such continuity is usually obtained through overlapping arrangements and suitable end bents of the bars. In the more critical contests, like in the case of buildings in seismic areas, more reliable continuity solutions are required. The same holds for blast scenarios. To this purpose a new type of coupling device assuring the bar continuity has been recently proposed. This device is made of a steel external shell, which encloses a certain volume around the bars to be connected. The interstitial volume is filled by VHS Concrete which embeds the bar and assures the continuity with the steel envelope. To assess the efficiency of this new device, many experimental tests were performed. In particular, it was analyzed the behavior under cyclic loading of columns having different height connected to the foundation structure by these continuity devices and the behavior of a beam-column junction. This paper presents the analysis for the investigations of the behavior of a precast column having section 0.5 x 0.5 meters and 5 meters high. Both experimental and numerical results are presented with particular attention to the definition of the numerical model.
Fire represents a significant danger for frame structures hosting industrial activities. In this ... more Fire represents a significant danger for frame structures hosting industrial activities. In this context, the numerical investigation of fire effects and fire induced collapse mechanisms becomes of interest. According to many studies on the topic, two failure modes are identified for a steel frame in fire: an outward (or sway) collapse and an inward (or no-sway) collapse. Above others the failure mode is determined by the following parameters: i) the acting load combination; ii) the typology of the column base restrain and iii) the two interacting mechanical effects of the fire (thermal expansion of the structural elements and thermal degradation of the steel properties). In this paper, a set of nonlinear transient analyses, which take into account for thermo-plastic material behavior and geometrical nonlinearities, has been performed in order to understand the influence of different parameters on the collapse mode of the frame.
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Presentations by Francesco Petrini
Papers by Francesco Petrini
DOTTORATO DI RICERCA IN INGEGNERIA STRUTTURALE E GEOTECNICA
Department of Structural and Geotechnical Engineering
Dipartimento di Ingegneria Strutturale e Geotecnica
DESIGN OF WIND-EXCITED CIVIL STRUCTURES:
PHENOMENOLOGICAL BASIS, PERFORMANCES ASSESSMENT, SOLUTIONS AND CASE STUDIES
What does the proper design of wind-excited civil structures need? What is the research practice in Wind Engineering today? How can we imagine tomorrow solutions for today open issues? The PhD course aims at providing some partial responses to the questions above, by lectures, seminars and brainstorming. Teaching lectures on established research and practice. The design of wind-excited Civil Structures needs, among others, sound phenomenological background in aerodynamics and aeroelasticity to set the problem, conceptual design abilities to solve the problem, analysis tools to assess the performance of candidate solutions. Teaching lectures select well-established fundamentals in Wind Engineering about the above issues. Seminars on current research. Additional seminars are focused on recent advances on selected topics in Wind Engineering. A view of research methods, as well as goals and achievements of selected research projects in the field. Brainstorming on research frontiers. As a closing loop step, brainstorming sessions are intended to seed some doubts and shed some light on open issues in Wind Engineering. Open minded, informal discussions towards potential step changes with respect to the current state of practice and knowledge. TARGET AUDIENCE: PhD students (main), Post-doctoral fellows (secondary), Researchers, Engineers, from both Italy and abroad. LAYOUT OF THE COURSE: • 3 days (8+8+4 hours), 20 hours in total • First two days: 6 hours of teaching lectures on established research and practice + 1 hours of seminars on current research + 1 hour of brainstorming on research frontiers • Third day: 4 hours of lectures on established research and practice
DOTTORATO DI RICERCA IN INGEGNERIA STRUTTURALE E GEOTECNICA
Department of Structural and Geotechnical Engineering
Dipartimento di Ingegneria Strutturale e Geotecnica
DESIGN OF WIND-EXCITED CIVIL STRUCTURES:
PHENOMENOLOGICAL BASIS, PERFORMANCES ASSESSMENT, SOLUTIONS AND CASE STUDIES
What does the proper design of wind-excited civil structures need? What is the research practice in Wind Engineering today? How can we imagine tomorrow solutions for today open issues? The PhD course aims at providing some partial responses to the questions above, by lectures, seminars and brainstorming. Teaching lectures on established research and practice. The design of wind-excited Civil Structures needs, among others, sound phenomenological background in aerodynamics and aeroelasticity to set the problem, conceptual design abilities to solve the problem, analysis tools to assess the performance of candidate solutions. Teaching lectures select well-established fundamentals in Wind Engineering about the above issues. Seminars on current research. Additional seminars are focused on recent advances on selected topics in Wind Engineering. A view of research methods, as well as goals and achievements of selected research projects in the field. Brainstorming on research frontiers. As a closing loop step, brainstorming sessions are intended to seed some doubts and shed some light on open issues in Wind Engineering. Open minded, informal discussions towards potential step changes with respect to the current state of practice and knowledge. TARGET AUDIENCE: PhD students (main), Post-doctoral fellows (secondary), Researchers, Engineers, from both Italy and abroad. LAYOUT OF THE COURSE: • 3 days (8+8+4 hours), 20 hours in total • First two days: 6 hours of teaching lectures on established research and practice + 1 hours of seminars on current research + 1 hour of brainstorming on research frontiers • Third day: 4 hours of lectures on established research and practice
Energy Efficient Buildings (EeB)
Factories of the Future (FoF)
This study focuses on the numerical analysis and testing of a high efficiency Energy Harvesting device, based on piezoelectric materials, with possible applications for the sustainability of smart buildings, structures and infrastructures. The development of the device is supported by ESA (the European Space Agency) under a program for the space technology transfer.
The EH device, harvests the airflow inside Heating, Ventilation and Air Conditioning (HVAC) systems, using a piezoelectric component and an appropriate customizable aerodynamic appendix or fin that takes advantage of specific air flow effects (principally Vortex Shedding), and can be implemented for optimizing the energy consumption inside buildings.
In the present research, focus is given on different relevant modelling aspects, explored both using numerical methods (by means of FEM and CFD models) and in wind tunnel testing. In particular, different configurations for the piezoelectric bender (including rectangular, cylindrical and T-shaped) are modelled, tested and compared. The calibration of the numerical models, useful for the optimisation of the final design, and the electrical modelling and losses calculation for the EH circuit, are provided, and the effective energy harvesting potential of the working prototype device in laboratory conditions is assessed. Additional aspects relevant to the successful implementation of the research project are shown, including the final design of the device and the possible market impact.