162,410 research outputs found
Interventions, Productions and Collaborations:the relationship between RAI and visual artists
Get PDFOn the 17th May 1952, before RAI Radiotelevisione Italiana Studios began their regular broadcast from Milan, the Spatialist painter and sculptor Lucio Fontana broadcast his own experimental ‘artwork’ on Italian television, beginning a fruitful relationship between RAI and visual artists. For some, it provided careers as designers and art directors, such as the painter Mario Sasso and the Arte Povera artist Pino Pascali, while for others, who were given unique access to RAI’s television apparatus, it was an opportunity to explore their own artistic experimentations with an expensive and exclusive medium, such as Carlo Quartucci and Gianni Toti. RAI also hosted seminal artists’ performances on screen including John Cage and Fabio Mauri. This article, based on documents and interviews collected during the Arts and Humanities Research Council funded project REWINDItalia, discusses these and other seminal cases as well as tracing and assessing the history of this fruitful and complex exchange between RAI and visual artists
Elementi di interfaccia per l’analisi di strutture murarie
No full textIl presente articolo riguarda la modellazione del comportamento meccanico di elementi in muratura intesi come sistemi eterogenei composti da malta, blocchi ed interfacce di connessione. La strategiacomputazionale che viene adottata consiste nel modellare separatamente i blocchi, i letti di malta ed le interfacce responsabili di fenomeni di decoesione malta-blocco; a tale scopo, si propone uno speciale modello di interfaccia che combina il danneggiamento con l’attrito. Si sviluppa una procedura numerica, basata sull’algoritmo backward di Eulero, per risolvere il problema evolutivo; per il passo temporale si utilizza invece la tecnica predictor-corrector a controllo di spostamenti. Si effettuano alcune applicazioni numeriche con lo scopodi verificare la capacità del modello e dell’algoritmo proposto nel riprodurre la risposta non lineare della muratura dovuta a fenomeni di degrado localizzati. Infine, si conduce lo studio della modellazione di un arco murario, confrontando i risultati numerici con quelli sperimentali; si dimostra la abilità del modello proposto nel simulare il comportamento globale della struttura ad arco in termini di carico ultimo e di meccanismo di collasso
Interface Elements for the Analysis of Masonry Structures
No full textThe present paper deals with the modeling of the mechanical
behavior of masonry elements regarded as heterogeneous systems,
made of mortar and bricks joined by means of interfaces. The
adopted computational strategy consists of modeling the brick
units, the mortar joints and the interfaces responsible for the
mortar-brick decohesion mechanisms; to this end, a special interface
model combining damage and friction is adopted. A numerical
procedure, based on the backward Euler time-integration
scheme, is introduced; the time step is solved adopting a displacement
driven predictor-corrector algorithm. Some numerical applications
are performed in order to assess the ability of the proposed
model and algorithm in reproducing the nonlinear response
of masonry elements. Finally, unreinforced and FRP-reinforced
masonry arches, for which experimental results are available, are
modeled and the mechanical response is investigated. The results
obtained by the numerical model are put in comparison with the
experimental ones, showing the ability of the proposed model to
simulate the behavior of the unreinforced and reinforced masonry
arches in term of ultimate load, nonlinear behavior and collapse
mechanism
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Damage propagation in a masonry arch subjected to slow cyclic and dynamic loadings
Get PDFIn the present work, the damage propagation of a masonry arch induced by slow cyclic and
dynamic loadings is studied. A two-dimensional model of the arch is proposed. A nonlocal damage-plastic
constitutive law is adopted to reproduce the hysteretic characteristics of the masonry material, subjected to
cyclic static loadings or to harmonic dynamic excitations. In particular, the adopted cohesive model is able to
take into account different softening laws in tension and in compression, plastic strains, stiffness recovery and
loss due to crack closure and reopening. The latter effect is an unavoidable feature for realistically reproducing
hysteretic cycles. In the studied case, an inverse procedure is used to calibrate the model parameters. Then,
nonlinear static and dynamic responses of the masonry arch are described together with damage propagation
paths
An approach for the modeling of interface-body coupled nonlocal damage
No full textFiber Reinforced Plastic (FRP) can be used for strengthening concrete or masonry constructions. One of the main problem in the use of FRP is the possible detachment of the reinforcement from the support material. This paper deals with the modeling of the FRP-concrete or masonry damage interface, accounting for the coupling occurring between the degradation of the cohesive material and the FRP detachment. To this end, a damage model is considered for the quasi-brittle material. In order to prevent strain localization and strong mesh sensitivity of the solution, an integral-type of nonlocal model based on the weighted spatial averaging of a strain-like quantity is developed. Regarding the interface, the damage is governed by the relative displacement occurring at bond. A suitable interface model which accounts for the mode I, mode II and mixed mode of damage is developed. The coupling between the body damage and the interface damage is performed computing the body damage on the bond surface. Numerical examples are presented
A coupled interface-body nonlocal damage model for the analysis of FRP strengthening detachment from cohesive material
Get PDFIn the present work, a new model of the FRP-concrete or masonry interface, which accounts for the coupling occurring between the degradation of the cohesive material and the FRP detachment, is presented; in particular, a coupled interface-body nonlocal damage model is proposed. A nonlocal damage and plasticity model is developed for the quasi-brittle material. For the interface, a model which accounts for the mode I, mode II and mixed mode of damage and for the unilateral contact and friction effects is developed. Two different ways of performing the coupling between the body damage and the interface damage are proposed and compared. Some numerical applications are carried out in order to assess the performances of the proposed model in reproducing the mechanical behavior of the masonry elements strengthened with external FRP reinforcements
Damage propagation in a masonry arch subjected to slow cyclic and dynamic loadings
No full textIn the present work, the damage propagation of a masonry arch induced by slow cyclic and dynamic loadings is studied. A two-dimensional model of the arch is proposed. A nonlocal damage-plastic constitutive law is adopted to reproduce the hysteretic characteristics of the masonry material, subjected to cyclic static loadings or to harmonic dynamic excitations. In particular, the adopted cohesive model is able to take into account different softening laws in tension and in compression, plastic strains, stiffness recovery and loss due to crack closure and reopening. The latter effect is an unavoidable feature for realistically reproducing hysteretic cycles. In the studied case, an inverse procedure is used to calibrate the model parameters. Then, nonlinear static and dynamic responses of the masonry arch are described together with damage propagation paths
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