Thermography multidimensional manifold space projection and principal curves extraction for material state evaluation

Eddy current pulsed thermography (ECPT) has been extensively used for detection and evaluation of conductive material defect, in that spatial-transient-stage thermography implies crucial information about material properties. This paper presents a material state evaluation method using multidimensional manifold space projection and similarity measurement of principal curves to characterize and track the variation of material properties. The mathematical theories about manifold space projection and principal curves extraction have been introduced and the corresponding physical models are established. The simulations and real experiments are conducted to validate the proposed method. The combination of manifold learning method with ECPT has shown promising potential in characterizing and tracking material properties.