Title: A Unified Approach to Accurate and Efficient Modeling of Composite Beams and Plates Keynote Lecture: Dynamics, Vibration and Control Track International Mechanical Engineering Congress and Exposition Phoenix, Arizona, Nov. 13 – 16, 2016 Abstract: Development of a unified approach is described for accurate and efficient modeling of a variety of structures for addressing aeroelasticity, dynamics, loads, stress recovery, etc. The approach was originally intended for modeling composite helicopter rotor blades. It achieves accuracy comparable to that of three-dimensional finite element analysis with orders of magnitude savings in computational effort. The types of structures that can be analyzed span a wide spectrum of geometries and materials, from beams made of thick composite laminates to ultra-thin plates made of micropolar isotropic materials. The basis for this approach is a mathematical technique called the variational asymptotic method, first presented by Berdichevsky in the late 70s and early 80s. This presentation summarizes the modeling approach and presents some of the key equations of the resulting analyses. Examples are presented that illustrate the accuracy and efficiency of the approach as implemented in the computer application Variational Asymptotic Beam Section (VABS) and the geometrically exact equations for beams. A brief description of a similar tool for plates and shells is also presented, along with a recent extension that extracts the elastic constants of Cosserat plates from 3D micropolar elasticity theory, including a closed-form solution for the plate drilling stiffness.