ON THE HOLOGRAPHIC DETECTION OF CORE-TO-SKIN DISBONDS IN COMPOSITE SANDWICH STRUCTURES

A cooperative research program between Alenia Composite Materials Research Center and United Technologies Research Center has provided the opportunity to study the phenomena of holographic nondestructive testing (NDT) of composite structures. This paper presents some results that clarify the physical mechanisms of flaw detection and describe the evolution of flaw deformation due to heating of the composite structure. Examples are given of testing with both photographic and electronic holography. On the basis of the results of this cooperative program, Alenia is applying holographic interferometry as an NDT technique for aircraft production parts.