Research on Spatial Filter Based Structural Imaging Method and the Evaluation Research on Complex Composite Structures

Abstract

A linear sensors array based damage imaging method called spatial filter are studied by some researches. It is a kind of directional filtering method that can be used to extract information of damage from a particular direction of signals and the other unwanted information from other directions is filtered out. But this method is only applied to damage monitoring of aluminum structures at current stage. In this paper, a spatial filter based impact and damage imaging method is proposed, which is implemented by adopting complex Shannon wavelet transform to construct analytic signals of time domain signals of piezoelectric sensors (PZTs) array to participate in signal synthesis process of spatial filtering imaging on composite structures instead of using structural parameters to fulfill the process on aluminum structures. An integrated multi-channel PZTs array scanning system (ISS) is developed for the purpose of impact and damage monitoring. An experiment is performed on a carbon fiber composite oil tank of an aircraft. The results show the promising performance of the system and that the damage position and impact angle which are relative to PZTs array can be estimated efficiently by this method.