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Preface 7th International Conference on Mechanics of Masonry Structures Strengthened With Composite Materials, MuRiCo 7 2021
No full textThis volume is a collection of edited scientific papers presented at the International Conference on Mechanics of Masonry Structures Strengthened with Composites Materials (MuRiCo7) held online (November 24-26, 2021). The previous Conferences, organised by AICO (Italian Association of Composites in Constructions, established in 1996), were held at the University IUAV of Venice (years 2000, 2004, 2009) and University of Bologna, a campus of Ravenna (2014) and a campus of Bologna (2017, 2019). This International Conference, MuRiCo7, was organized by AICO under the patronage of DICAM Department of University of Bologna, DA Department of University of Bologna, and RILEM (International Union of Laboratories and Experts in Construction Materials, Systems and Structures). The Conference represented a forum to promote and exchange the latest theoretical, computational, and experimental research works finalised to the design of structural strengthening of historic masonry constructions.
The MuRiCo7 covers a wide range of general topics:
• Mechanics of historical masonry: testing and modeling
• Performance of strengthened masonry with composites (FRP, FRCM, TRM, SRG)
• Performance in masonry/composites coupling: bond, special connections, fracture, fatigue, fire, durability
• Appropriate composites techniques evolution for historical construction strengthening
• First aid and provisional devices in historical structures with collapse risk after seismic shock
• Criticism on existing guidelines, standards, and praxis in masonry/composites coupling
• Sustainability, circular economy, life-cycle assessment, and recycling.
The Editors would like to thank the members of the Scientific Committee and the organizers of the special mini symposiums for their support that contributed to the success of the Conference. Furthermore, we express our gratitude to AICO, promoting and organizing the Conference.
The Editors
G. Castellazzi, C. Gentilini and A. Di Tommaso
ALMA MATER STUDIORUM University of Bologna, November 202
Motet à une voix / Legrenzi, comp.. Partiro : ariette ; La tua pena...[etc.] : ariette / A. Scarlatti, comp. ; Maria Castellazzi-Bovy, S ; Yvonne Thibout, vlc ; Claude Crussard, clav.
No full textTitre uniforme : Legrenzi, Giovanni (1626-1690). Auteur ou responsable intellectuel. [Motet à une voix. Voix, basse continue]Titre uniforme : Scarlatti, Alessandro (1660-1725). Compositeur. [Partirò. Voix, basse continue]Titre uniforme : Scarlatti, Alessandro (1660-1725). Compositeur. [La tua pena. Voix, basse continue]Titre uniforme : Scarlatti, Alessandro (1660-1725). Compositeur. [Speranza. Voix, basse continue]Comprend : Motet à une voix / Legrenzi, comp. ; Maria Castellazzi-Bovy, S ; Yvonne Thibout, vlc ; Claude Crussard, clav. ; Partirò / A. Scarlatti, comp. ; Maria Castellazzi-Bovy, S ; Yvonne Thibout, vlc ; Claude Crussard, clav. ; La tua pena / A. Scarlatti, comp. ; Maria Castellazzi-Bovy, S ; Yvonne Thibout, vlc ; Claude Crussard, clav. ; Speranza / A. Scarlatti, comp. ; Maria Castellazzi-Bovy, S ; Yvonne Thibout, vlc ; Claude Crussard, clav.Enregistrement : (France) Paris, 13-01-193
α-Ga2O3 SBD switching performance in PFC application
No full textThis paper presents an in-depth experimental characterization of the switching performance of a state-of-the-art Ga2O3 rectifier used in a real commercial application. Specifically, a Schottky-barrier-diode (SBD) is tested, fabricated with an α-substrate orientation technology, a competitive manufacturing option over the hitherto somewhat more common β orientation. As an application case-study, a boosting power factor correction (PFC) circuit is considered, which allows for the straightforward investigation of the chip operating under varying duty-cycle and load conditions and which corresponds to a potentially large volume market (consumer) application for this technology. A parametric analysis is carried out, by varying the switching frequency, output power and heat-sink temperature of the device. The results indicate that □-Ga2O3 SBDs have the potential to compete with SiC SBDs in the 600 V class, when the performance to cost ratio is taken into account
Preface
No full textThis volume is a collection of edited scientific papers presented at the International Seminar
on Mechanics of Masonry Structures Strengthened with Composites Materials (MuRiCo4) held
in Ravenna (September 9‐11, 2014).
Previous meetings, organised by AICO (Italian Association of Composites in Constructions,
established in 1995), were held at University IUAV of Venice (years 2000, 2004, 2009).
This International Seminar, MuRiCo4, was organized by AICO under patronage and
sponsorship of DICAM department of University of Bologna and patronage of University IUAV
of Venice. It is attended by Researches from several countries. It represents a forum to
promote and exchange latest theoretical, computational and experimental research work
finalised to the design of structural strengthening of historic masonry constructions.
The MuRiCo4 covers a wide range of topics:
Analysis of Mechanics of Masonry and Models;
Testing and Computational Modelling of Masonry macro‐elements under static and
dynamic loadings;
Performance of Strengthened Masonry with Composites (FRP, FRCM, TRM, SRG);
Bond, Local Damage, Fatigue and Connections Performance in Masonry/Composites
Coupling;
Design Approaches and Inspection Programs of Masonry Structures strengthening;
Durability, Health Monitoring (optic fibres ...), Maintenance and Repair strengthened
Masonry;
Advanced bio‐composites and Nanotechnology for strengthening Historical
Constructions
Appropriate Composites Technique Evolution for Historical Constructions
strengthening.
Acceptance of Composites Technique Application for seismic protection of Monuments.
Criticisms on Existing Guide Lines, Standards and Praxis Restoration Rules on
Historical Masonry/Composites Coupling.
The Editors would like to thanks the members of Steering Committee, Professors A. Cecchi, J.
Jasienko, G. Leoni, M. Savoia, F. Ubertini, and all the member of the Scientific Committee for
their suggestions and help for the success of the seminar. Furthermore, we express our
gratitude to the AICO promoting and organizing the seminar with cooperation of the affiliated
industrial partners KERAKOLL‐The GreenBuilding Company and Ruredil. A special thank to
the Fondazione Flaminia of Ravenna for sponsorship and operative local support.
Finally we would like to thank all those who helped us to organise this scientific event, in
particular Dr. Daniela Bufo from AICO that was with us the driving force of the meeting in
Ravenna, a site of the Multi Campus at University of Bologna
Spatio-temporal modelling of crop co-existence in European agricultural landscapes
No full textThe environmental risk of growing genetically modified (GM) crops and particularly
the spreading of GM genes to related non-GM crops is currently a concern in European
agriculture. Because the risks of contamination are linked to the spatial and temporal
arrangements of crops within the landscape, scenarios of crop arrangement are required
to investigate the risks and potential coexistence measures. However, until recently,
only manual methods were available to create scenarios.
This thesis aims to provide a flexible referenced tool to create such scenarios. The
model, called LandSFACTS, is a scientific research tool which allocates crops into
fields, to meet user-defined crop spatio-temporal arrangements, using an empirical and
statistical approach. The control of the crop arrangements is divided into two main
sections: (i) the temporal arrangement of crops: encompassing crop rotations as
transition matrices (specifically-developed methodology), temporal constraints (return
period of crops, forbidden crop sequences), initial crops in fields regulated by temporal
patterns (specifically-developed statistical analyses) and yearly crop proportions; and
(ii) the spatial arrangements of crops: encompassing possible crops in fields, crop
rotation in fields regulated by spatial patterns (specifically-developed statistical
analyses), and spatial constraints (separation distances between crops). The limitations
imposed by the model include the size of the smallest spatial and temporal unit: only
one crop is allocated per field and per year. The model has been designed to be used by
researchers with agronomic knowledge of the landscape. An assessment of the model
did not lead to the detection of any significant flaws and therefore the model is
considered valid for the stated specifications. Following this evaluation, the model is
being used to fill incomplete datasets, build up and compare scenarios of crop
allocations. Within the GM coexistence context, the model could provide useful support
to investigate the impact of crop arrangement and potential coexistence measures on the
risk of GM contamination of crops. More informed advice could therefore be provided
to decision makers on the feasibility and efficiency of coexistence measures for GM
cultivation
Error estimation by compatibility in patches for plate structures
No full textError estimation is a key tool in modern finite element technology in order to verify and validate the finite element simulations, as well as to improve results and control the error, when combined with adaptivity. An efficient and practical way to derive a posteriori error estimators is offered by recovery procedures. The error, generally in stress based norms, is estimated by comparing the original finite element solution with the recovered one. The major steps forward in using recovery procedures were taken with the Superconvergent Patch Recovery (SPR) developed by Zienkiewicz and Zhu [1] and the Recovery by Equilibrium in Patches (REP) developed by Boroomand and Zienkiewicz [2]. Both these procedures have been successfully applied to plate problems in [3]. Recently, a new superconvergent procedure called Recovery by Compatibility in
Patches (RCP) has been proposed by one of the authors [4] and shown to provide an excellent basis for error estimation in 2D problems [5].
Thin structures like plates and shells constitute an important class among finite element analyses because of their large application fields. With this in mind, the aim of the present paper is to develop an extension of the RCP-based error estimation to Reissner-Mindlin plates finite element analysis. The basic idea of this procedure is the same as the RCP in its original version, that is to recover stress resultants by enforcing compatibility over patches of elements.
Displacements computed by the finite element analysis are prescribed on the boundary of the patch, and improved stress resultants are computed by minimizing the complementary energy of
such a sub-model. The resulting procedure is simple, efficient, numerically stable and does not need any knowledge of superconvergent points. Some numerical examples involving thin and thick plates under different loading and support conditions are given.
References
[1] Zienkiewicz OC, Zhu JZ, The superconvergent patch recovery and a posteriori error estimates. Part I: The recovery technique, International Journal for Numerical Methods in Engineering, 33, 1992, 1331–1364.
[2] Boroomand B, Zienkiewicz OC, An improved REP recovery and the effectivity robustness test, International Journal for Numerical Methods in Engineering, 40, 1997, 3247–3277.
[3] Boroomand B, Ghaffarian M, Zienkiewicz OC, On application of two superconvergent recovery procedures to plate problems, International Journal for Numerical Methods in Engineering, 61, 2004, 1644–1673.
[4] Ubertini F, Patch recovery based on complementary energy, International Journal for Numerical Methods in Engineering, 59, 2004, 1501–1538.
[5] Benedetti A, de Miranda S, Ubertini F., A posteriori error estimation based on the superconvergent Recovery by Compatibility in Patches, International Journal for Numerical Methods in Engineering, in press
On the performances of parametric finite elements when geometry distortions occur
No full textParametric finite elements can lose their performance when distortions of the element geometry arise. Geometry distortions cause global co-ordinates to be non-linear functions of local co-ordinates when described through the co-ordinate transformation. This transformation is ruled by the inverse of the Jacobian matrix. In this paper a new method to investigate the effects of element distortions on the performance of parametric finite elements is presented. By inspecting analytically the Jacobian matrix, the proposed method investigates, on a rational basis, the relation between distortions and the interpolating functions of parametric finite elements. Common examples are employed to test the accuracy of the information provided by the method. Comparison with extant methods confirm the ability of the proposed technique to give useful information about the performance of an investigated element when geometry distortions occur
It takes three to Tango: Balancing actor centricity to pursue a strategic reorientation in B2B markets
No full textBy shedding light on the interconnectedness of B2B markets, Service-Dominant Logic has brought forward the idea that B2B organizations can be facilitators of value co-creation rather than business suppliers, suggesting that a new source of competitive advantage might lie in orchestrating relationships with other actors besides their direct business clients. This study delves into the initiatives of strategic reorientation undertaken by two native B2B organizations to pursue this logic: Balanced centricity. We develop an empirical model that provides a dynamic understanding of market strategies grounded in the interdependence among B2B and B2C orientations. Our model also highlights the crucial role of salespeople in harmonizing value co-creation, suggesting that they might act as institutional intrapreneurs within triadic business structures. The study also holds implications for B2B managers' agenda. We uncover the crucial role of service innovation and adopting an ambidextrous approach to the strategic management of salespeople
Prediction of ultrasonic guided waves excitability to support the non-invasive assessment of human long bones
No full textThe characterization of bones via axial ultrasonic transmission techniques can be fully exploited only once the complexities of guided wave propagation are unveiled. Generally, plate/cylindrical waveguide models, where the soft tissues and their damping role are generally neglected, are used to identify the propagating waves in the bone. Here, a numerical strategy for a more rigorous simulation of guided wave propagation in elongated bones is proposed. First, from a computed tomography image of a human leg a three-dimensional finite element (FE) mesh of the problem is built by converting voxels into elements. At this level, the mechanical properties of bones and soft tissues can be obtained converting the Hounsfield units. If necessary, the FE mesh can be enhanced by smoothing the outer surfaces of the bone and/or skin. Next, time-transient three-dimensional explicit FE simulations are performed to simulate the propagation of stress waves along the bone with and without the soft tissues. The propagative energy is revealed by processing the bone time-responses with a 2D-FFT transform suitable for guided waves extraction. Finally, a representative bi-dimensional cross-section of the bone only is used to set the guided wave equation by means of a Semi-Analytical Finite Element (SAFE) formulation. Via SAFE, the dispersion curves are obtained and compared with the 2D-FFT energy map. The proposed strategy can support the research on non-invasive techniques based on stress waves for the assessment of long bones
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