Sviluppo di sci estensimetrati per la rilevazione in pista delle sollecitazioni su sci da competizione

Aim of the work was the development of a pair of strain gauged skis suitable for strain measurement during real courses in a snow field: this would enable to measure the distribution of bending and twisting moments acting along the ski during real events. Two racing skis were used and 11 couples of unidirectional strain gauges were symmetrically applied to the top foil of the skis, at 11 sections regularly distributed along the ski: a total number of 22 quarter bridge strain channels were eventually applied to each ski. The ski were calibrated during laboratory tests under different bending and torsion test conditions, in order to evaluate the calibration constants correlating the bending and twisting applied moments and the strain signals. The stiffness properties in bending and torsion of different sections along the ski were evaluated both by optical and contact methods, in order to have all information needed to estimate the ski instantaneous deflected shape on the basis of the bending and twisting moment diagrams collected from the field data acquisitions in slalom. Pilot tests performed on a slalom course with giant and special slalom poles confirmed the reliability of the developed skis and allowed to obtain the bending and torsion diagrams at each sections during the courses.