High-Speed Optical Strain Measurement by FPGA—based 2D Speckle Pattern Correlation

摘要

Optical strain measurement is commonly used for the evaluation of the mechanical stress during dynamic mechanical tests of materials and structures. This work describes the setup and realization of a high speed speckle-based extensometer for accurate and robust non-contacting strain sensing at measurement rates above 1 kHz. The high measurement performance is achieved by implementing a fast and robust digital signal processing algorithm based on the evaluation of the phase information in speckle patterns on state-of-the-art FPGA hardware.