An Approach for Estimating Flexural Rigidities of a Ski's Cross Section

Abstract

The authors have already proposed a numerical approach for calculating flexural rigidities of a ski's cross section. In the present study, to discuss the accuracy and practical usefulness of the numerical approach, an experimental approach is developed. The experimental approach estimates the flexural rigidities of a ski using experimental results obtained by bending test and torsional test. Although the ski has a laminated construction, the flexural rigidities for non-uniform orthotropic plates are estimated. Three kinds of test pieces with uniform laminated cross sections in the longitudinal direction and five test pieces with non-uniform laminated cross sections, which is similar to the ski, were used for the numerical calculations and experimental estimations. From comparisons of numerical values with values estimated experimentally, it was shown that the differences between numerical and estimated values areless than 15% of the maximum value of flexural rigidities. Furthermore, from the simulation of a skiing turn for five test pieces similar to the ski, it was shown that the maximum difference of "characteristic of ski turn" is less than 4% of the maximum "characteristic of ski turn". This means, the difference of "characteristic of ski turn" due to the difference of the flexural rigidities becomes far less than the difference of the flexural rigidities itself. From the abovementioned reasons it was concluded that the numerical approach for calculating flexural rigidities of a ski's cross section, and the experimental approach for estimating flexural rigidities are useful.