Contactless measurements of dynamic deflections of plates and shells

Experimental research into problems of buckling and post-buckling behaviour of thin walled elements and structures subjected to dynamic or variable repeated loading requires special techniques for monitoring and measurement of buckled patterns of moving thin walls. The paper presents experience with optical experimental techniques which enable such measurements. The dynamic stereophotogrammetry and shadow moire methods are discussed and compared to the vibration pattern image (VPI) technique. The dynamic shadow moire utilizes CCD camera video records of the moving fringes and their computer aided analysis.