Damage detection in structures under variations of temperature and clamping conditions

For many mechanical and structural applications, the damage detection is a fundamental issue in order to assess the health of the system under analysis. Since environmental conditions significantly affect the modal characteristics of the structures, it is a severe task to understand whether the structure is damaged or not by simply inspecting the modal parameters at a specific instant. This is the reason why a method for the damage identification must eliminate these external factors, so that they can be fruitfully adopted in many civil and mechanical applications. The technique proposed in this paper is based on the Principal Component Analysis and it is able to eliminate the effects of many non-negligible external factors. In particular, the article is focused on the temperature and the clamping conditions, playing a fundamental role when analyzing structures or mechanical parts that need to be frequently mounted and dismounted. In this paper, we show that both effects can be removed by means of the Principal Component Analysis technique. Successively, some numerical simulations and experimental tests on a cantilever beam are presented, analyzed under different temperatures and boundary conditions, showing that the method can detect and quantify the damage.