Elasto-acoustic Wave Source Localization in Composite Plate-like Structure using Muti-rosetts Sensing

Abstract

The rapid technical progress in the engineering (applied science/technology) requires more advanced materials. The desire to reduce the weight of structure and reduce their manufacturing costs may affect the safety and reliability of designed structure. The structural damage can occur due to many factors which are difficult to predict in advance, e.g.: sudden impact loads. An external impact can cause an internal damage in the material with no visible marks on the external surfaces of the composite element. The possible hidden damage can be the source of a further mechanical deterioration of the composite structural element. Damage detection in the structures is an active research area since decades. Number of the studies is carried out in order to meet this objective, particularly, the identification of the damage size and location or to find direction of the impact event. Recently on of the promising monitoring technique method is based on fibre optic sensors (e.g. fibre Bragg grating sensors, FBG). It is due to the advantages of FBG sensors such as small size and weight, high corrosion resistance or no calibration requirements. Also it is very easy to multiplex FBG sensors and make rosette array that can be implemented on different kind of structures. The goal of the research is to analyse impact detection capability of different FBG strain rosettes types. Additionally the sensitivity and area of working individual rosette will be considered. The experiment will be carried out on composite plate with the use of impact and/or elasto-acustic wave source. The proposed impact detection method by rosette network can be applied on structures like plane wings, turbine blades or ship masts. The locations of detected impacts can be further analysed by more sophisticated methods (terahertz spectroscopy or infrared thermography).