DIGITALLY-ANALYZED SHADOW MOIRE FRINGE PATTERNS

AN IMPERFECT SPOT-WELDED JOINT WILL LOCALLY CHANGE THE MECHANICAL PROPERTIES AND PRODUCE AN ANOMALOUS STRUCTURAL RESPONSE. THIS LOCAL CHANGE IN THE DISPLACEMENT FIELD WILL BE OBSERVED, RECORDED AND ANALYZED USING THE NEW APPROACH, PROPOSED HERE. A COMBINATION OF A SHADOW-MOIRE USED FOR FIELD ACQUISITION OF SURFACE DISPLACEMENTS TOPOGRAPHY AND DIGITAL IMAGE ANALYSIS. A SOPHISTICATED SOFTWRE WILL BE DEVELOPED TO ANALYZE THE RECORDED SURFACE-DISPLACEMENT PATTERN, AND COMPARE TO THE "NORMAL" DISPLACEMENT BEHAVIOR. TO ASCERTAIN THE FEASBILITY AND MERITS OF THE PROPOSED APPROACH, SPECIMEN CONTAINING BAD WELDS WILL BE EXAMINED AND DEFECT DETECTION ABILITY EVALUATED.