We are concerned with the development of a three-dimensional (3D) full-field high-speed digital image correlation (DIC) measurement system using a single camera, specifically aimed at measuring large out-of-plane displacements. A system has been devised to record images at ultrahigh speeds using a single camera and a series of mirrors. These mirrors effectively converted a single camera into two virtual cameras that view a specimen surface from different angles and capture two images simultaneously. This pair of images enables one to perform DIC measurements to obtain 3D displacement fields at high framing rates. Bench testing along with results obtained using a shock wave blast test facility are used to show the validity of the method.

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Advanced polymeric composites are increasingly used in high-performance aircraft structures to reduce weight and improve efficiency. However, a major challenge delaying the implementation of the advanced composites is the lack of accurate methods for material characterization. Accurate measurement of three-dimensional mechanical properties of composites, stress–strain response, strength, fatigue, and toughness properties, is essential in the development of validated analysis techniques accelerating design and certification of composite structures. In particular, accurate measurement of the through-thickness constitutive properties and interlaminar tensile (ILT) strength is needed to capture delamination failure, which is one of the primary failure modes in composite aircraft structures. A major technical challenge to accurate measurement of ILT properties is their strong sensitivity to manufacturing defects that often leads to unacceptable scatter in standard test results. Unacceptable failure mode in standard test methods is another common obstacle to accurate ILT strength measurement. Characterization methods based on non-contact full-field measurement of deformation have emerged as attractive alternative techniques allowing more flexibility in test configuration to address some of the limitations inherent to strain gauge-based standard testing. In this work, a method based on full-field digital image correlation (DIC) measurement of surface deformation in unidirectional open-hole compression (OHC) specimens is proposed and investigated as a viable alternative to assessing ILT stress–strain, strength, and fatigue properties. Inverse identification using a finite element model updating (FEMU) method is used for simultaneous measurement of through-thickness elastic constants with recovery of the maximum ILT stress at failure for characterization of strength and fatigue S–N curves.

This paper presents results of an experimental investigation on the tensile response of "hybrid" 3D woven composites (H3DWC), where "hybrid" refers to different constituent fibers, including carbon, glass, and kevlar that are integrally woven into a single preform. The H3DWCs are made through a 3D textile weaving process. Five different versions of hybridized architectures were examined to determine the progression of failure under tensile loading. The different types of H3DWC were compared against one another to understand the benefits of hybridization and the resulting performance enhancements.

The Advanced Composites Consortium is a US Government/Industry partnership supporting technologies to enable timeline and cost reduction in the development of certified composite aerospace structures. A key component of the consortium's approach is the development and validation of improved progressive damage and failure analysis methods for composite structures. These methods will enable increased use of simulations in design trade studies and detailed design development, and thereby enable more targeted physical test programs to validate designs. To accomplish this goal with confidence, a rigorous verification and validation process was developed. The process was used to evaluate analysis methods and associated implementation requirements to ensure calculation accuracy and to gage predictability for composite failure modes of interest. This paper introduces the verification and validation process developed by the consortium during the Phase I effort of the Advanced Composites Project. Specific structural failure modes of interest are first identified, and a subset of standard composite test articles are proposed to interrogate a progressive damage analysis method's ability to predict each failure mode of interest. Test articles are designed to capture the underlying composite material constitutive response as well as the interaction of failure modes representing typical failure patterns observed in aerospace structures.