2016 Volume 15 Issue 4 Pages 309-314
When external force or stress is applied to the object, displacement could be occurred. Therefore, accurate displacement distribution measurement is important to maintain of their structures. Sampling moiré (SM) method is one of the optical full-field displacement measurement method used in field experiments. In the SM method, the in-plane displacement distribution can be accurately determined using a digital camera and repeated patterns. In this study, we developed a dynamic out-of-plane displacement distribution measurement method based on the SM method using a single camera. In the proposed method, the out-of-plane displacement was measured by considering the relationship between the change of grating pitch in captured image and the magnification of used camera lens. Some researchers proposed the out-of-plane displacement distribution measurement methods by using two or multiple cameras. Compared with their methods, our method has advantages including fast, ease-of-use, and inexpensive equipment. The basic principle and an experimental validation of measurement accuracy were presented. As an application, this technique can be potentially extended to measure the out-of-plane direction vibration frequency in full-field.
