Combination of FEM simulations and shearography for defect detection on artwork

Abstract Digital shearography is an interferometric technique, which is often used for defect detection on composite structures. The measurement is fast and non‐destructive and thus suitable for the application to cultural heritage. However, a major drawback of the technique is the indirect measurement, because surface strain is used to detect subsurface defects. So the determination of depth, size, and type of the defects is rather difficult. To overcome this issue, we use a combination of finite element method simulation and shearographic measurement. Due to the comparison of both data sets, the inverse problem can be solved in a more reliable way. In this paper, we investigate the application of finite element method simulation for an improved defect detection on anisotropic material. We validate the technique on a wooden sample with notches on the backside.