Papers by Keyword: Modelisation

Abstract: This article discusses the characterization and modeling of the elastic behavior of a semi-hard steel used in incremental forming operations which implies great loading speeds at high temperatures and large springback after each passage of the roller. The knowledge of the elastic behavior is essential to correctly predict these springbacks during forming. The objective is therefore on the one hand the characterization of the elastic response of the material under different conditions and on the other hand the definition of a model that describes the material behavior with as much precision as possible. To this end, two models, one phenomenological and the other built on more physical basis, are considered.

Abstract: In this study, we present the manufacturing process of two new composites materials in the form of long fibers of polylactic-acid (PLA) or polypropylene (PP), reinforced by cellulose whiskers micro-fibers loads. In order to evaluate the mechanical properties of these advanced materials, a several uniaxial tensile tests were carried out. The PP and the PLA have initially been spinning without the addition of cellulose whiskers micro-fibers. In order to study the effects of cellulose whiskers micro-fibers reinforcements in the Mechanical behavior of the PLA and PP filaments, we determinate the proprieties of these advanced material from the tensile results. For the PP composite filaments material case, the whiskers reinforcement increases Young's modulus and failure resistance, but it reduces the limit strength failure. For the PLA composites the addition of 1% wt of cellulose whiskers from the total volume fraction of the material, increase the Young’s modulus more than 50% and a decrease of the failure resistance and the limit strength of composite. The obtained composites fibers are very rigid and brittle. What follows, that the addition of cellulose whiskers micro fibers in PP matrix, provides mechanical properties more convenient compared to the PLA matrix.