Wednesday  |  Salon 7  |  05:20 PM–05:40 PM

#15683, Preliminary Study on Improving DIC Analysis Using Optical Flow to Reject Outer Images

The digital image correlation method (DIC) determines the displacement/ deformation and strain field by tracing the original random surface patterns generated artificially. The DIC method has become extremely popular in the experimental area because DIC is always considered to be a whole-field, non-contact, and easy-use method. The DIC has been used to determine material properties, measure the displacement and strain field of soft materials, or be challenging on mounting sensors to the materials, such as biomaterials, tissues, cells, and the meta-materials of the structure designed.
Other than determining the material properties, the DIC methods are also used to monitor structural health in the field; most industrial applications and structural health monitoring use optical systems to capture the images for extracting the displacement and deformation. However, the imaging systems are not always still because the imaging system is constantly subjected to environmental disturbances, such as low-frequency vibration, wind, unpredicted force impacts from wild creatures, and human activities or natural events. Even though the imaging system is always well protected, disturbances inevitably cause the imaging system to move. To ensure the images, particularly the video streams, recorded using the imaging system possess the correct information and proper for evaluating deformation and strain using DIC. Therefore, it is essential to propose a method to minimize the possible errors caused by camera movement or to be aware that the movement of the imaging system occurred. In this study, the optical flow popularly used to evaluate the image shifts among frames is implemented to detect the disturbance introduced movement and reject the images recorded at that time interval. Then, the video streams embedded with and without unwanted movement on the imaging system are analyzed using commercial DIC software to calculate the displacement and strain field. The displacement and strain obtained using two different series images will be compared and discussed at the end.

Chi-Hung Hwang   Taiwan Instrument Research Institute
Chun-Wei Lai   National Tsing Hua University
RongQing Qiu   National Tsing Hua University
Hsin-Ping Peng   National Tsing Hua University
Wei-Chung Wang   National Tsing Hua University