FULL-FIELD STRUCTURAL RESPONSE OF COMPOSITE STRUCTURES: ANALYSIS AND EXPERIMENT

Several applications of a three-dimensional digital image correlation system to the investigation of the static response of composite structures tested and analyzed at NASA Langley Research Center are presented. The digital image correlation system that was used to measure full-field three-dimensional displacement components over global and/or local areas of the structure is briefly described. Representative results obtained from several examples are then presented. These examples include the compression response of a notched composite panel, the compression response of an anisotropic composite panel with and without impact damage, the geometric shape measurement and compression response of a composite cylinder with a reinforced cutout, and the structural response of a shear-loaded stiffened composite panel. Results that illustrate recent enhancements to the digital image correlation system are also presented. These enhancements include an improved capability to compute in-plane strains from the full-field displacements and the capability to measure the surface profile of closed structures, such as cylinders. Experimental and analytical results are presented and compared. The results illustrate the benefits of obtaining full-field displacement and strain measurements in validating analytical models and in understanding the structural response of the test specimens.