Comportement viscoelastique a grande deformation des composites elastomeres - textiles utilises dans les equipements de protection

Wearing protective gloves can reduce the occurrence of injuries, but it often involves additional muscular constraints and reduced dexterity which are related to the glove material stiffness. As a consequence, workers may choose not to wear protective gloves, exposing themselves to high risks of hand injuries. Several mechanical test methods have been used for characterizing film and fabric flexibility. However, most of them are based on uniaxial bending, which may not be representative of the type of solicitations suffered by a glove in usage. Moreover, they don't take into account the hand-glove interface which may change according to hand fitting. The main purpose of this study is to characterize in the first time the flexibility of protective gloves covering a broad range of stiffness. In the second instance, the viscoelastic behaviour of protection materials such as elastomer and textile at large deformation is modelled using Zener rheological model.;1. The first one is the multidirectional test method, inspired from the ASTM D 4032 standard method, which allows for the measurement of protective gloves stiffness. This new method is described in article 1 as the free-deforming multidirectional technique and has been used to measure the stiffness of twenty eight models of protective gloves. For a comparison, the stiffness of these gloves was also characterized by the KESF along both directions (longitudinal and transversal).;The stiffness measurements provided by both mechanical methods, the developed free-deforming multidirectional technique and the KESF, have been compared to the results of a psychophysical evaluation test in which human subjects had to rank the gloves according to their stiffness. They were also compared to the biomechanical results in the project IRSST 099-376. The analysis of the correlations between the glove stiffness measurements produced by the two mechanical test methods and the results of the psychophysical and biomechanical evaluation tests shows a much better agreement with the free-deforming multidirectional method, which indicates that this method describes much more closely the stiffness of protective gloves as wearers perceive it. This can be attributed to the multidirectional deformations applied to the glove during the test, which better simulate the deformations subjected to gloves in service. Two additional practical advantages of the free-deforming multidirectional technique should be mentioned: first, it is very easy to implement, the simple set-up of probe and drilled plate being inserted in a mechanical test frame with limited requirements in terms of load capacity. Second, this method is non destructive, especially since the glove is deformed only through a 10-mm course of the probe. This new method should prove as a valuable tool for protective glove manufacturers in their search for improving their product quality, allowing for the characterization of their existing products in terms of stiffness and for the development of new ones better fitting workers' needs.;2. The second method, called here the fixed technique, is presented in the second paper of this work. It characterizes the flexibility of gloves that are worn tight fitted. Its validity was theoretically verified for elastomer materials.;Concerning the study of the protection gloves stiffness, two mechanical methods are proposed in this work:;Concerning the study of the viscoelastic behaviour of protection materials such as elastomer and textile at large deformation, two non linear rheological models are proposed in papers 3 and 4 of this work. Both of them are based on Zener model. A validation of the description was performed with nitrile rubber and textile fabric in the case of a loading-unloading hysteretic loop. A good agreement of the theoretical description with experimental results was obtained. This simple description of the hysteretic behaviour of elastomers and textiles as a function of the strain rate provides a useful tool for estimating the dissipated energy at various strain rates, with potential application in the design of protective gloves.