Automatic crack monitoring using photogrammetry and image processing

This manuscript presents an integrated approach for automatic crack monitoring combining photogrammetry and image processing. In summary, the strain field obtained from photogrammetric data is used to map the cracked areas where image processing is applied. All processing is completely automatic since only a threshold value, related to the width of the crack, needs to be provided. Direct Shear Tests (DSTs) have been selected for calibration, validation and also as an experimental example. In conclusion, critical areas, the corresponding crack pattern and all related measures (e.g. crack width, length, area or path) could be provided for any stage of loading, until the complete failure of the specimens. Furthermore, all outputs require low computational cost, thus allowing monitoring vast campaigns of laboratorial tests. (C) 2012 Elsevier Ltd. All rights reserved.