Proceedings home preface contents authors keywords copyright reference ©2012 Civil-Comp Ltd				Paper 254 Analytical and Computational Perspectives of Multi-Scale Theory for Homogeneous, Laminated Composite, and Sandwich Beams and Plates A. Tessler1, M. Gherlone2, D. Versino2 and M. Di Sciuva2 1Structural Mechanics and Concepts Branch, NASA Langley Research Center, Hampton VA, United States of America 2Aerospace Engineering Department, Politecnico di Torino, Italy Keywords: laminated composites, sandwich structures, refined zigzag theory, multiscale, inter-laminar damage, C0-continuous finite elements. full paper (pdf) - reference Lightweight and high-performance characteristics of advanced composite materials have spurred a wider range of application of these materials in military and civilian aircraft, aerospace vehicles, and naval and civil structures. To realise the full potential of composite structures for primary load-bearing components, further advances in structural design, analysis methods, and failure prediction and progressive damage methodologies are necessary. This paper reviews the theoretical foundation and computational mechanics aspects of the recently developed shear-deformation theory, called the refined zigzag theory (RZT). The theory is based on a multi-scale formalism in which an equivalent single-layer plate theory is refined with a robust set of zigzag local layer displacements that are free of the usual deficiencies found in common plate theories with zigzag kinematics. In the RZT, first-order shear-deformation plate theory is used as the equivalent single-layer plate theory, which represents the overall response characteristics. Local piecewise-linear zigzag displacements are used to provide corrections to these overall response characteristics that are associated with the plate heterogeneity and the relative stiffnesses of the layers. The theory does not rely on shear correction factors and is equally accurate for homogeneous, laminated composite, and sandwich beams and plates. Regardless of the number of material layers, the theory maintains only seven kinematic unknowns that describe the membrane, bending, and transverse shear plate-deformation modes. Derived from the virtual work principle, RZT is well-suited for developing computationally efficient, C0-continuous finite elements; formulations of several RZT-based elements are highlighted. The theory and its finite element approximations thus provide a unified and reliable computational platform for the analysis and design of high-performance load-bearing aerospace structures.