Speckle patterns for multiscale monitoring of deformation

摘要

The strain sensitive patterns (SSP) play an important role in digital image correlation (DIC) techniques. An unsuitable chosen speckle patterns may result in inaccurate results. A new SSP based on multiscale of the speckle sizes is proposed in this work. A brief description of its synthesis algorithm is presented. An algorithm is proposed for evaluation of effectiveness of speckle pattern used for multiscale monitoring of in-plane displacement and strain fields. Eight different structures computer generated are studied. The images of these patterns are numerically deformed as to simulate rotation or one axis tensile. Cross-correlation between each pattern and its deformed state is found. The patterns' quality is evaluated and presented in tabular and graphical form. SSP containing features appropriate for both high and low magnification is chosen as a result.