LIN Long rong1, ZHONG Shun cong1,2*, FU Xin bin3, YU Jin3, HUANG Xue bin3

 

(1. Laboratory of Optics, Terahertz and Non destructive Testing, School of Mechanical Engineering and Automation,

 

Fuzhou University, Fuzhou 350108, China; 2. Fujian Key Laboratory of Medical Instrument and Pharmaceutical

 

Technology, Fuzhou 350002, China; 3. Xiamen Special Equipment Inspection Institute, Xiamen 361000, China)

 

 

Abstract: In order to ensure the detection capability of pulsed infrared thermography (PIT) for composites, finite element method (FEM) was employed to mimic non destructive testing (NDT) of composites using pulsed infrared thermography. FEM models with different heat flux boundary conditions applied to the upper surface of the sample and with natural convective heat transfer boundary condition applied to the bottom surface, were established. Different temperature distributions on the surface of composites were investigated due to different internal defects. The parameters such as pulse shape, heating time, and defect material, in term of their influence on the temperature distribution and contrast on the surface of defective composites was discussed. The experimental results demonstrate that the temperature difference and contrast of composites surface would increase with the increasing of flaw depth and size whilst larger heat flux density would result in larger temperature difference but no effect on the contrast. FEM can provide the numerical model for PIT based defect detection of composites

 

Key words: infrared thermography; finite element analysis; non destructive testing; flaw inspection