1,720,993 research outputs found
Sistemi costruttivi reversibili per edifici direzionali: sostenibilità e riuso
No full textLe emissioni riconducibili al settore delle costruzioni rappresentano secondo il rapporto di settore delle nazioni unite del 2022 circa il 37% del totale delle emissioni generate da tutte le attività umane.
Per far fronte a questa problematica il dibattito nell’ambito della produzione edilizia ha iniziato a valutare l’opportunità di superare modelli economici lineari in favore di modelli circolari
originariamente ideati in campo industriale. L’adozione di tali modelli porta quindi a considerare le fasi di smantellamento e fine vita inserendo le stesse all’interno della progettazione proponendo quindi l’implementazione della reversibilità in quanto proprietà dei sistemi costruttivi.
La ricerca in oggetto si inserisce in questo contesto con l’obiettivo di valutare i rapporti tra reversibilità, riuso e sostenibilità, identificando strategie e prassi, definite dall’autore caratteristiche di interesse, tramite le quali informare il design tecnologico di sistemi costruttivi reversibili.
La metodologia adottata segue quindi quattro fasi principali: la valutazione critica dello stato dell’arte; la definizione di un campo di indagine innovativo e compatibili; la definizione quindi valutazione di scenari composti da combinazioni di caratteristiche di interesse; infine, lo sviluppo di un caso studio volto a valutare la sostenibilità di un design basato su caratteristiche di interesse.
Dalla prima fase emerge la presenza di CI applicabili a diverse scale, da quella strategica a quella sub-componentistica; la seconda fase delimita il capo di combinazioni non riscontrate nello stato dell’arte e non reciprocamente antitetiche; le valutazioni svolte nella terza fase hanno consentito di determinare quale scenario sviluppare come caso studio studiando l’interazione tra CI; la quarta restituisce un sistema costruttivo composto da moduli dispiegabili aggregati a scacchiera definito nelle sue parti per il quale è stato possibile effettuare valutazioni di impatto ambientale incorporato e totale su un ciclo di vita pari a 50 anni.
Il confronto tra i risultati ottenuti e valori presenti in letteratura configura infine un potenziale impatto positivo dell’impiego di caratteristiche di interesse alla base della progettazione
An augmented lagrangian method to solve three-dimensional nonlinear contact problems
No full textA finite element formulation to deal with the friction contact problem between an elastic body and a rigid foundation is presented. An augmented Lagrangian method, which incorporates two Lagrange multipliers and a slack variable in the constraint equation, is developed. In this method, the solution is achieved through a Newton-Raphson monolithic iterative strategy and leads to simple implementation. Examples are provided to demonstrate the accuracy of the proposed algorithm.Fil: Cavalieri, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin
Do Androids Dream of Curtain Walls? How Image Generating AIs Represent Contemporary Architecture
No full textAmerican author Philip K. Dick introduced the world to the concept of androids that could be trained on the memories of real people, in a similar fashion the development of Ais is based on the use of human-produced data to learn in a statistical way how to describe or even draw something. Said training can be executed using dataset with different degrees of specificity or curation in a specter going from the punctual curation of individual data up to the employment of vast, un-curated datasets. The latter case is representative of how modern open-source models like stable diffusion are trained to be able to generate images either from a textual or a graphical input. Using said models the authors run a series of tests, to assess how models that didn’t undergo a heavily specific training tend to represent contemporary architecture, what are the limitations in using generic pre-trained models, and what is their potential in directing the output toward specific topological features. The paper concludes summarizing the features that the model identified with contemporary architecture in terms of morphology, stylistic characteristics, and strategical aspects, while defining the limits emerged from testing
Numerical solutions for frictional contact problems based on a mortar algorithm with an augmented Lagrangian technique
Full text linkThis work presents a frictional contact formulation to solve three-dimensional contact problems with large finite displacements. The kinematic description of the contacting bodies is defined by using a mortar approach. The regularization of the variational frictional contact problem is solved with a mixed dual penalty approach based on an augmented Lagrangian technique. In this method, the numerical results do not depend on the definition of any user defined penalty parameter affecting the normal or tangential component of forces. The robustness and performance of the proposed algorithm are studied and validated by solving a series of numerical examples with finite displacements and large slip.Fil: Cavalieri, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones En Metodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones En Metodos Computacionales; ArgentinaFil: Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones En Metodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones En Metodos Computacionales; Argentin
An augmented Lagrangian technique combined with a mortar algorithm for modelling mechanical contact problems
Full text linkA finite element formulation for three dimensional (3D) contact mechanics using a mortar algorithm combined with a mixed penalty-duality formulation from an augmented Lagrangian approach is presented. In this method, no penalty parameter is introduced for the regularisation of the contact problem. The contact approach, based on the mortar method, gives a smooth representation of the contact forces across the bodies interface, and can be used in arbitrarily curved 3D configurations. The projection surface used for integrating the equations is built using a local Cartesian basis defined in each contact element. A unit normal to the contact surface is defined locally at each element, simplifying the implementation and linearisation of the equations. The displayed examples show that the algorithm verifies the contact patch tests exactly, and is applicable to large displacements problems with large sliding motions.Fil: Cavalieri, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico. Centro de Investigación de Métodos Computacionales; ArgentinaFil: Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico. Centro de Investigación de Métodos Computacionales; Argentin
Toward an Inclusive and Independent Fruition of Architecture: The Use of Scale Models and Augmented Reality
Full text linkWhile there are many places in Italy that cater to the population with low
vision or who is blind, for example the "Museo Tattile Statale Omero" in Ancona,
the remarks made by the Unione Italiana Ciechi e Ipovedenti (U.I.C.I) of Bologna
on the issue state that "the issues produced by perceptual barriers, inherent in visual
disabilities, do not find adequate answers in the current accessibility regulations".
To integrate the accessibility of museums and other cultural services, considered by
UNESCO as a fundamental human right that must be granted to people with
disabilities (article 30, Convention on the Rights of Persons with Disabilities) the
authors present a design, in its early stages, of a system that aims to make the fruition
of scale models independent for users with low vision or who are blind. Said system
aims to integrate some sort of augmented reality to haptic perception by reproducing
sound cues to help users with disabilities navigate a single, or a series of models
without any outside aid. The system is based on the deployment of technological
plinths to support the scale models. This approach is well fit for retrofitting existing
scale models while integrating the navigation system in an effective fashion. The
activation of the plinths will be triggered using a smartphone app (either using NFC
or Bluetooth) and will reproduce a set routine to guide the user in the haptic
exploration of the models. On the outer rim of the plinths a series of triggers and
devices will be placed for the user to interact, while leaving some space between the
elements to house details at a larger scale or braille plaques. The triggers will be
distinguished by their shape, a proud start trigger and a recessed end trigger; the
interface is completed by an array of 8 speakers (one each 45°) with the possibility
of ulterior sound emitting elements embodied in new models. The current design
also defines the properties of the material that will be used in the prototyping phase
by excluding rough surfaces that could introduce haptic noise and suggesting the
use of thermoplastic polymers or stabilized wood over metals (since a metallic
surface could be problematic in exterior installations due to its high thermal
conductivity). The concurrent deployment of multiple plinths will consent the
independent navigation and queuing of users in a contained exhibit by triggering a
positional sound to guide them, while in urban context the app will have to be
integrated with systems that implemented detailed voice guidance such as google
maps. The paper ends by describing the future prototyping stages the system is
expected to go through to fine tune the preliminary design
Determination of wear in internal combustion engine valves using the finite element method and experimental tests
Full text linkA methodology for the analysis of wear in internal combustion engine valves is proposed, which is the result of the combined use of numerical and experimental techniques. The numerical solutions are obtained using a specialized Finite Element Method, where a mortar contact algorithm is used to model a flexible-flexible contact along with an adhesive wear law. The experimental results are obtained in a wear testing rig specifically designed to evaluate wear parameters in valve operating conditions. A good agreement was found between the experimental worn profiles and the numerical computations of wear at the contact surfaces.Fil: Cavalieri, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Zenklusen, Fernando. Mahle Argentina S.A.; ArgentinaFil: Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentin
Non-smooth model of a frictionless and dry three-dimensional revolute joint with clearance for multibody system dynamics
Full text linkDefects in kinematic joints notably influence the relative position and the dynamic response of the bodies in a multibody system. For example, clearance in joints produces impacts that generate wear and/or vibrations which can break a component or generate a drastic life reduction of a mechanical system. In this work, a new element for modeling three-dimensional revolute joints with clearance is proposed. The equations of motion are solved with a non-smooth generalized-α time integration scheme, in which the constraints at velocity and position levels are satisfied exactly without requiring the user to define any penalty parameter. The numerical behavior of the proposed joint is analyzed through four numerical examples where the powerfulness of the proposed methodology is demonstrated.Fil: Cavalieri, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; ArgentinaFil: Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentin
Three-dimensional numerical solution for wear prediction using a mortar contact algorithm
Full text linkA finite element formulation to compute the wear between three-dimensional flexible bodies that are in contact with each other is presented. The contact pressure and the bodies displacements are calculated using an augmented Lagrangian approach in combination with a mortar method, which defines the contact kinematics. The objective of this study is to characterize the wear rate coefficients for bimetallic pairs and to numerically predict the wear depths in new component designs. The proposed method is first validated with the classical pin-on-disc problem. Then, experimental results of wear for the metallic pairs used in internal combustion engine valves and inserts are presented and are taken as a reference solution. An example is provided that shows agreement of the numerical and experimental solution. Finally, the proposed algorithm is used to predict the wear in an application example: the wear in an internal combustion engine valve.Fil: Cavalieri, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET- Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Centro de Investigación de Métodos Computacionales; Argentina;Fil: Cardona, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET- Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Centro de Investigación de Métodos Computacionales; Argentina
- …
