A constrained optimization scheme is used to determine the stacking sequence that maximizes the extension-twist coupling in a composite laminate while maintaining its hygrothermal stability. The results are compared with the hygrothermally stable laminates obtained by stacking a set of rotated [0/90] plies. It is found that the laminate configurations resulting from the optimization scheme have improved coupling. Their coupling magnitude, however, is very sensitive to changes in fiber angle.
Eight sets of laminates with varying extension-twist coupling were fabricated and tested using a custom loading transducer designed to allow the laminate end to twist while undergoing extension. Test results were compared with analytical predictions.
Elastically tailored composite laminates are those laminates that have been designed with specifically tailored stiffness parameters. These parameters can be sized to give an out-of-plane response to in-plane loading, resulting in deformation modes not found in conventional homogeneous materials.
Three different methods of testing extension-twist-coupled specimens are discussed. The benefits and limitations of each of the methods are highlighted. Quantitative results for each of the testing methods using a hygrothermally stable specimen are shown and compared to determine the applicability and suitability of each of the methods.
A comparison of data with predictions from a shear deformation sublaminate plate theory and finite element method (FEM) is presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.