The Out-of-Plane Strain Measurement of Digital Speckle Pattern Shearography on Sandwich Plates with Insert

• Main Authors: cruise, 林鈺棠
• Other Authors: Huang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/29437857927902801732

碩士 === 國立中正大學 === 機械系 === 93 === Abstract Sandwich honeycomb plates generally were as structures of the flying vehicle by the air industry, due to which have characteristic for light mass and could be to accept higher strength. The main topic of this research is to study the structure of the sandwich honeycomb plate. Structure of the sandwich honeycomb plate with potting material and insert can increase the strength of the structure. For achieve nondestructive－testing of sandwich honeycomb plate with potting material and through-the-thickness insert. Here is bring up the mode of digital speckle shearography. Rely on the capability of Michelson shearing mechanism to measure displacement derivative and simplify the optical frame of speckle shearography. It is more simple to deal with optical frame and no longer to do the work of strict alignment adjustment for optic axis. Furthermore, CCD camera be used in place of negative to record light intensity and combine digital image process software directly see instantaneous variation of fringe pattern for two type of approximate displacement derivative. Digital speckle shearography ( DSS ) approve to eliminate the trouble of traditional interferometry for develop negative and set up Fourier optics filter to reconstruct fringe pattern again. Furthermore, DSS can increase advantage for instantaneous measure and dealing. For validation purpose, the analytical analysis was introduced to compare with the result of digital speckle shearography. Comparison between the results of digital speckle shearography and analytical revealed a convincing agreement. The results of this study could be applied on designing the sandwich structure with insert in the future. Keyword: sandwich honeycomb plate, digital speckle shearography, nondestructive-testing, insert.