Simultaneous in-plane and out-of-plane deformation measurement by speckle multi-recording method

• In-plane and out-of-plane simultaneous deformation measurement method based on speckle interferometry is proposed.
• Multi-recording technology in speckle interferometry is also proposed.
• The problems in the multi-recording technology are discussed.
• The new method is applied to the analysis of phenomenon of buckling in a beam.

An in-plane and out-of-plane deformation simultaneous measurement method using only two speckle patterns grabbed before and after deformation of an object with rough surfaces using two cameras has been proposed. However, there are some problems concerning the setup of optical system, the aspect ratio of grabbed image data and so on in the conventional method. To solve these problems, the new optical system is proposed by using the multi-recording technology. Though multi-recording technologies have been already employed conveniently in the off-axis digital holography, the technologies have not been used functionally enough in speckle interferometry. In this paper, an in-plane and out-of-plane deformation simultaneous measurement is performed by the proposed method based on multi-recording technology in speckle interferometry. From experimental results, it can be confirmed that the proposed optical system can measure simultaneously in-plane and out-of-plane deformations in high resolution by one camera.