Search results for "scienza"
showing 10 items of 1408 documents
Numerical and Experimental Analysis of the Frictional Effects on 4ENF Delamination Tests Performed on Unidirectional CFRP
2015
Abstract Progressive delamination in composite materials under static or fatigue loading condition are, in many structures, one of the predominant cause of failure. In the paper, an accurate study of quasi-static delamination growth under mode II loading condition is conducted. Several experimental tests are performed on composite laminates consisting of unidirectional carbon/epoxy layers. Four-point end-notched flexure (4ENF) test is employed in order to characterize the mode II interlaminar fracture toughness. The R-curve is obtained by means of optical and numerical determination of crack tip position. The energy release rate and the crack length are calculated through experimental deter…
Microwave response properties of epoxy resin composites filled with graphitic fillers
2014
Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite (EG), natural graphite, and coarse, medium and fine artificial graphites have been prepared. The dielectric permittivity strongly increases with graphite particle size. This effect is related to the distance of the investigated filler concentrations to the composites' percolation threshold. Microwave experiments show that exfoliated graphite is, out of investigated graphite particles, the only one being a really effective additive for producing electromagnetic (EM) interference (EMI) shielding: 2 wt.% epoxy/EG is absolutely opaque to electromagnetic radiation at 30 GHz.
Interlaminar decohesion and inner-layer damage in composite structures
2008
The effect of through-thickness compressive stress on mode II interlaminar fracture toughness
2017
Abstract The effect of through-thickness compressive stress on mode II interlaminar fracture toughness is investigated experimentally and replicated numerically. The modified Transverse Crack Tensile specimen recently proposed by the authors is used, together with an experimental device designed to apply a constant transverse compressive stress on the surface of the specimen. Experiments are conducted using IM7/8552 specimens for different compressive stresses, ranging from 0 to 100 MPa, covering all the practical applications commonly encountered in the aeronautical industry (e.g., tightened filled holes or bolted joints). It is shown that mode II interlaminar fracture toughness increases …
A global perspective on effectiveness of aid for trade
2013
Recent global initiatives on debt relief and development assistance call for increasing aid for trade to the poorest countries. The paper applies a multi-country computable general equilibrium model to measure the effectiveness of alternative aid for trade categories. The findings show that aid for trade policies expand trade and alleviate international income inequalities in the recipient countries, that will benefit mainly from aid for trade adjustment and technical assistance.
An Assessment of Carousel Value-Added Tax Fraud in The European Carbon Market
2017
AbstractThe literature on the European Union Emission Trading System (EU ETS) is by now very rich. Much is known about the efficiency, the effectiveness, and the environmental and distributional impacts of the EU ETS. Less, however, is known about the carousel value-added-tax (VAT) fraud phenomena in the European carbon market. This article evaluates the welfare effects of carousel VAT fraud in the EU ETS using a computable general equilibrium (CGE) analysis. According to our findings, if VAT fraud occurs in the EU ETS, the effects on welfare for the EU Member States are negative, with welfare loss significantly higher than the VAT fraud value. This article also discusses the reverse charge…
Modelling the labour market of minority ethnic groups
2012
Abstract This paper investigates the effects, in terms of labour and macroeconomic indicators, of closing the gap between the ethnic minority employment rate and the overall population rate using a computable general equilibrium modelling framework. The labour market has been integrated by indicators related to ethnicity, employment status and occupational class. The policy test has been designed for the UK. According to the results, the policy actions aimed to remove the barriers that contribute to the unemployment of the minority ethnic groups improve not only the employment and occupational status of these groups, but the effects are also positive in terms of aggregate employment, GDP, t…
KLUM@GTAP: Introducing Biophysical Aspects of Land-Use Decisions into a Computable General Equilibrium Model a Coupling Experiment
2008
In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness and potenti…
Creativity in Conceptual Spaces
2014
The main aim of this paper is contributing to what in the last few years has been known as computational creativity. This will be done by showing the relevance of a particular mathematical representation of G"ardenfors's conceptual spaces to the problem of modelling a phenomenon which plays a central role in producing novel and fruitful representations of perceptual patterns: analogy.
Efficient formulation of a two-noded geometrically exact curved beam element
2021
The article extends the formulation of a 2D geometrically exact beam element proposed by Jirasek et al. (2021) to curved elastic beams. This formulation is based on equilibrium equations in their integrated form, combined with the kinematic relations and sectional equations that link the internal forces to sectional deformation variables. The resulting first-order differential equations are approximated by the finite difference scheme and the boundary value problem is converted to an initial value problem using the shooting method. The article develops the theoretical framework based on the Navier-Bernoulli hypothesis, with a possible extension to shear-flexible beams. Numerical procedures …