Standard Practice for Shearography of Polymer Matrix Composites and Sandwich Core Materials in Aerospace Applications| vibration stress shearography, vacuum stress shearography, thermal shearography, structural sandwich constructions, shearography, sandwich core materials, sandwich constructions, polymer matrix composites (PMC), nondestructive testing (NDT), nondestructive inspection (NDI), nondestructive evaluation (NDE), laminates, honeycomb core, high performance composites, high modulus fibers, fiber-reinforced polymer matrix composites, composites, aerospace composites