Structural modelling of multilayer skis with an open source FEM software

Abstract

The development process of mountaineering skis is characterized by a rapid design phase due to the continuous changes in materials, customer’s requirements and manufacturing processes. Nowadays, this type of ski is still characterized by a design process based on a basilar trials and error technique. Finite Elements Analysis (FEA) could introduce a different approach to overcome main disadvantages, such as time, of this actual design method. For this reason, the main purpose of this work is centered on the development of a reliable FE model of an existing mountaineering ski, capable to forecast the mechanical behavior of the real tool. Firstly, all mechanical properties of materials that were composing the ski were characterized. Tensile tests in the two principal directions were performed on flat dog-bones shaped specimens. Secondly, Digital Image Correlation (DIC) was combined with results obtained from tensile tests in order to approximate the four in-plane (XY) elastic properties, namely, the two elastic modules, the shear module and the Poisson ratio (Ex, Ey, Gxy, νxy). Results of the cross-correlation process were after checked with the help of numerical simulations. FEA simulations were reproducing the tensile-tests configuration. Finally, geometry, mesh and simulations-run of the ski were performed in the open source environment Code_Aster/Salome-Meca. The results of simulations of the ski were compared with the response of the real ski in three-point bending tests. Differences of 2.5%-10% with respect to the real ski were observed for the different modelling techniques.