Search results for "COMPRESSION"

Nature log-analytique du volume des sous-analytiques

2000

Using a preparation theorem for subanalytic functions and Lipschitz stratification for compact subanalytic sets we prove that volumes of slices of globally subanalytic sets and density have a log-analytic nature. We also prove that the set of parameters for which the volume of fiber is finite is globally subanalytic.

Volumetric Reconstruction of Unorganized Set of Points with Implicit Surfaces

2005

Many solutions exist to rebuild a three-dimensional object represented by a set of points. The purpose of our work is to provide an automatic reconstruction from an unorganized cloud, describing an unknown shape, in the aim to compute its volume. The approach employed in this paper consists in filling the object's interior with isosurfaces of potential fields and to use their fusion property in order to find the full volume and the continuous shape of the sampled object. Thus, the first step of our reconstruction is to search a correct interior for the object described by the set of points. Then, comes the positioning of implicit primitives into the cloud, deep inside of it and close to the…

Large-scale structural pattern as the result of the interplay between compression and extension during chain building: the case of the Sicily belt (c…

2010

EVOLUZIONE DELLA COMPOSIZIONE GRANULOMETRICA DI SABBIE POMICEE SOTTOPOSTE A COMPRESSIONE 1-D FINO AD ALTE PRESSIONI

2012

Nell’articolo si riportano i risultati di uno studio sperimentale sull’evoluzione della composizione granulometrica di sabbie pomicee sottoposte a compressione 1-D fino a pressioni di 100 MPa. La sperimentazione è stata eseguita su sabbie asciutte con coefficiente di uniformità compreso tra 1.18 e 1.66 e con diametro iniziale dei grani compreso tra 0.18 e 2mm. Il crushing dei grani è significativo per tutte le granulometrie indagate a partire da pressioni efficaci basse (dell’ordine di appena 150 kPa). I risultati della ricerca dimostrano che, anche per queste sabbie dotate di un doppio ordine di pori – intergranulari e intragranulari - esiste una composizione granulometrica limite superior…

The Effects of Structure on the One Dimensional Compression Behaviour of a Porous Calcarenite

2019

Human settlements built on weak rock deposits are often characterized by instabilities or collapse that may involve the underground cavities and consequently the above buildings. Underground calcarenite quarries in Marsala have been involved in a number of collapses that have seriously damaged numerous buildings. Unfortunately proper engineering solutions have not yet been identified according to the different and special cases and to the properties of this structured material. In order to investigate structure effects on the behaviour of the porous calcarenite of Marsala, this paper presents a comparison between the one dimensional compression behaviour of the intact rock and of the same w…

The evolution of grain-size distribution of sands under 1-D compression

2009

Crushing of particles is a fundamental mechanisms leading to deformation of particulate materials at medium and high stresses. As crushing progresses, the grain-size distribution undergoes modifications, causing changes of the porosity, grain-to-grain contacts and of their density (”packing density” and “grain contact”). The main aim of the research is the identification of trends in the modifications of characteristic diameters (D10, D15, D25, etc.) in function of the applied stress s´v. Results of a laboratory research programme on the crushing of dry sands compressed under one-dimensional conditions, at vertical effective stresses ′v up to 120 MPa, are reported in the paper. Tests have …

Caratterizzazione meccanica di alcune tipologie di tamponamento

2009

L’utilizzo di modelli che prevedono l’inserimento dei tamponamenti nelle maglie di telaio richiede la conoscenza preliminare delle caratteristiche meccaniche del tamponamento. A tal fine si possono seguire diverse strade, tutte basate su prove di laboratorio: 1) determinazione diretta della risposta a taglio del tamponamento su campioni di muratura; 2) determinazione della risposta a compressione lungo gli assi principali di campioni di muratura rappresentativi del tamponamento e utilizzo dei risultati per dedurre il comportamento a taglio; 3) determinazione della risposta a compressione dei componenti della muratura (malta ed elementi resistenti) da correlare alle caratteristiche meccanich…

Analisi teorico-sperimentale del comportamento flessionale di colonne in calcestruzzo fibrorinforzato

2009

Influenza delle armature sul comportamento in compressione di colonne in calcestruzzo ad alta resistenza

2010

COMPRESSIVE BEHAVIOR OF LAMINATED GLASS COLUMNS

2014

This paper examines the behavior in compression of glass columns having tee (T) transverse cross-sections. The work highlights the issues recurring in the design of glass columns in rapid diffusion in the transparent architecture such as: - flexural and torsional buckling; - long-term effects and effects related to the temperature; - glued connections between single panels. In the work expressions are given for the calculation of the loadcarrying capacity of columns. The cases of full connection and absence of connection between the panels are analyzed and discussed. The comparison between the analytical and the experimental results highlights that in the case of glass columns with T cross-…