Numerical and experimental analysis of the torsional and impact behaviour of the shell of a ski touring boot

At the production level, it is very important for a company to be able to numerically simulate the behaviour of a new product. This is because, once one has the geometric model of the part and knows the material with which it will be produced, it will already be possible to know its behaviour and identify any critical points, with the possibility of correcting them, proceeding by successive iterations, without having the need to always have to produce prototypes to test experimentally, with all the associated costs and time. For this reason, this thesis carried out in collaboration with Tecnica Group focused on the numerical simulation of the behaviour of the shells of the Markab ski boot. In particular, the aim of this work is to numerically simulate the behaviour of the shells during torsion and impact tests and to carry out experimental tests in order to derive quantities to validate the simulations. The focus was on torsional behaviour because torsional stiffness is an important parameter describing the performance of ski boots, and on impact resistance because shells must pass a standard tip impact test for safety. The thesis work was therefore structured as follows: 1) A brief introduction to explain what ski mountaineering and downhill skiing consist of and to introduce the Markab shell under study. 2) Correction of the CAD model of the shell, inserts and soles to obtain solid bodies. 3) Experimental torsion tests and analysis of the results obtained. 4) Numerical simulations of torsion and comparison of results obtained with experimental tests. 5) Experimental impact tests with an instrumented stem and analysis of the results obtained. 6) Characterisation of shell materials at low temperatures and high strain rates to then implement their properties in numerical impact simulations.