On Viscoelastic Viscoelastic Viscoelastic Modelling of Poly Ethylene Terephthalate Behaviour during Multiaxial Elongations Slightly over the Glass Transition Temperature
The mechanical response of Polyethylene Terephthalate (PET) in elongation is strongly dependent on temperature, strain and strain rate. Near the glass transition temperature Tg, the stress-strain curve presents a strain softening effect vs strain rate but a strain hardening effect vs strain under conditions of large deformations. The main goal of this work is to propose a viscoelastic model to predict the PET behaviour when subjected to large deformations and to determine the material properties from the experimental data. To represent the non–linear effects, an elastic part depending on the elastic equivalent strain and a non-Newtonian viscous part depending on both viscous equivalent strain rate and cumulated viscous strain are tested. The model parameters can then be accurately obtained trough a comparison with the experimental uniaxial and biaxial tests.
Constitutive model for the finite deformation stress–strain behavior of poly(ethylene terephthalate) above the glass transition
Abstract A constitutive model for the finite deformation stress–strain behavior of poly(ethylene terephthalate) (PET) at temperatures above the glass transition temperature is presented. In this temperature regime, the behavior of PET is strongly dependent on strain rate and temperature; PET also experiences strain-induced crystallization at these temperatures. The constitutive model accounts for the rate and temperature dependence of the stress–strain behavior by modeling the competition between molecular orientation processes and molecular relaxation processes. The model is fully three-dimensional and is shown to be in good agreement with experimental data over a wide range in strain rates and temperatures as well as under both uniaxial compression and plane strain compression loading conditions.
Fascism and the right in Europe, 1919-1945
This new text places interwar European fascism squarely in its historical context and analyses its relationship with other right wing, authoritarian movements and regimes. Beginning with the ideological roots of fascism in pre-1914 Europe, Martin Blinkhorn turns to the problem-torn Europe of 1919 to 1939 in order to explain why fascism emerged and why, in some settings, it flourished while in others it did not. In doing so he considers not just the 'major' fascist movements and regimes of Italy and Germany but the entire range of fascist and authoritarian ideas, movements and regimes present in the Europe of 1919-1945.