International audienceA visco-hyperelastic constitutive model, based on an original approach initially developed by (Billon, 2012) and applied to amorphous rubbery polymers for a one-dimensional formalism, was extended in this study to three-dimensional constitutive equations based on a thermodynamic framework. The model was applied to a semi-crystalline polyamide polymer, PA66. The experiments included tension and shear testing coupled with synchronized digital image correlation and infrared measurements device for capturing the time, temperature, and stress state dependence, as well as the complex thermomechanical coupling exhibited by the material under large deformation. A notion of equivalent strain rate (based on the time–temperature principle superposition) was also introduced to show its capability to build master curves and therefore decrease the number of testing needed to build a material database. The model is based on the Edward Vilgis theory (1986) and accounts for chains network reorganization under external loading through the introduction of an evolution equation for the internal state variable η, representing the degree of mobility of entanglement points. The model accounting for the equivalent strain rate notion was calibrated using master curves. The thermomechanical model agreed well with the experimental mechanical and temperature measurements under tension and shear conditions. The approach developed in this study may open a different way to model the polymer behavior

. 3D FEM simulations of shoulder milling operations on a 304L stainless steel. Simulation Modelling Practice and Theory, Elsevier, 2012, 22, pp.13-27. 10 The final aim consists to obtain realistic numerical cutting forces for shoulder milling operations.

This paper presents some experimental results dealing with the mechanical performance of composite beams obtained by bonding Glass Fibre Reinforced Polymer (GFRP) rectangular pultruded panels by means of an epoxy structural adhesive. The flexural response of these bonded beams was compared with those obtained by the pultrusion process with the same geometrical and material properties. As a matter of fact, no significant loss of performance emerged in terms of failure load; moreover, an increase of pre-failure stiffness was observed. This result may allow us to consider bonded GFRP beams as a viable simplification within the field of composite structures.