Guided wave damage detection for alpine skis

This paper describes the results of an experimental study of guided ultrasonic wave interaction with damage in an alpine ski. The ski is chosen to act as a surrogate for built-up composite structures commonly used in aerospace and many other engineering applications. The study begins by characterizing the optimal actuation signal to generate observable guided wave signals in sensors located along the ski. Using this frequency, the experiment continues by determining the effect of through-thickness hole damage. The damage is located between the sensors to allow for both pitch-catch and pulse-echo approaches to be considered. Data were collected for various hole diameters to determine the sensors’ ability to detect worsening damage in the ski. Interestingly, results showed the damage difference signals collected by comparing damaged and pristine cases actually decreased in value as the diameter of the hole increased. These results indicate further study is required to fully understand how the lateral boundaries of the structure affect the signals obtained from damaged configurations.