Application of Digital Image Monitoring System in Strain Measurement of Cantilever Steel Beam

Abstract:

The realization of strain measurement based on digital image processing technique is discussed. Combined with the strain measurement principle and the optical imaging feature, considered the axisymmetrical and non-axisymmetrical distortion, the automatic surface-fitting calibration method based on region growing is adopted. Cubic polynomial is applied to establish the relationship between the object space and pixel coordinate system. The expectations based on wavelet coefficients are used for sub-pixel edge detection, measurement accuracy can reach 0.02 pixels. Accuracy of displacement for strain measurement achieves micrometer-level. The theoretic validity and practical feasibility of the system are proved by the strain measurement of a cantilever steel beam.

• Periodical: Applied Mechanics and Materials (Volumes 29-32)
• Pages: 112-117
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.29-32.112
• Online since: August 2010
• Authors: Peng Hui Li, Yin Ping Wen, Wen Guang Zhao, Hong Ping Zhu
• Keywords: Image Processing, Strain Measurement, Subpixel, Surface Fitting, System Calibration, Wavelet Analysis

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