Comportement mécanique de tissus à voiles, en fibres synthétiques, sous sollicitations biaxiales et déformation finie

摘要

This work deals with theoretical, experimental and numerical studies of the mechanical behavior of woven materials and laminated fabrics, made with synthetic fibers, for the manufacture of sails, such as polyester or Kevlar. An original theoretical approach was proposed, it allows taking into account the specific behavior of yarns, of coating and their interactions. The resulting modeling allows describing the behavior of woven materials and laminated fabrics, in the case of complex cyclic biaxial loadings, taking into account finite deformations, nonlinear viscous effects, time-independent irreversibility and anisotropy. The implementation of this modeling was performed in a finite element code, in order to produce an operational tool for the design and calculation of sails. The proposed theoretical approach has been validated through a detailed experimental study, which was conducted on material “Dacron SF HTP Plus”. Thus, we performed various monotonous and cyclic tensile tests, which were strain or load-controlled. Some of these tests include relaxation sequences. These tests were conducted in the axes of the material, in the warp and weft directions, as well as off-axis or bias orientations, from 5 ° to 45 ° with respect to the warp direction. Further experimental results were also obtained on a laminated “Kevlar X15” and a woven “Dacron SF HTM simple” fabrics. Finally, numerical simulations of the biaxial tensile test were performed and were used for studying homogeneity of the stress and the strain fields in the cases of three different contours of biaxial-tensile samples.