PROCESSING OF RESULTS FROM A THERMAL FEM ANALYSIS USING THE LOCK-IN METHOD AND COMPARISON WITH EXPERIMENT

This article dealt with the comparison of results obtained from an experiment and from the numerical thermal FEM analysis. Sample with defects were printed on a 3D printer. A thermal wave from the halogen lamp to excite the front surface of the sample was used in the next step and the response was measured by a thermal camera. After processing the data in the software DisplayIMG, a phase image was created representing the 2D image of the material at a certain depth under the surface of the model. Lock-in method was applied to the results from the numerical thermal FEM analysis and the phase image was created. The programs code were created in MATLAB for a 4 points, multiple points and differential lockin method which were compared with the results from the experiment.