“…Holes and surface corners are very common forms of defects in many kinds of materials such as metals, ceramics, plastics, and composites. For example, shrinkage defects exist in casting, injection moulding, and welding, holes caused by incomplete healing at interfaces are found in the fused filament fabrication parts, corrosion defects often locate at the outer surface of a pipeline girth weld, and voids with V‐shape corners are easy to occur in multilayered composites, bonded joints, and coating structures . On the other hand, metal grids with artificial square, diamond, and triangle holes have been used in common stealth structures .…”