Stress/strain basis pairs for anisotropic materials

The conjugate pair approach, when constructed from an upper-triangular decomposition of the deformation gradient, allows constitutive relations to be constructed without a need to introduce invariant theory. This approach to constitutive construction, previously proposed by the authors, is expanded upon in this paper to include anisotropic materials. Data acquired from 2D polyvinyl-ester composite panels, laid up with a single fiber orientation, are used to contrast the capability of our theoretical model with that of the transversely isotropic fiber model derived from invariant theory by Spencer. (C) 2017 Elsevier Ltd. All rights reserved.