BLACKSBURG, Va., May 1, 2012 – M.W. Hyer, N. Waldo Harrison Professor Emeritus of Engineering Science and Mechanics, delivered the SDM Lecture at the 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials (SDM) Conference in Honolulu April 23rd. The title of the lecture was "Tailoring of Composite Structures Using Spatially Varying Fiber Orientations." Fiber orientations within contemporary fiber-reinforced composite structures generally do not vary with spatial location. Hyer’s plenary lecture focused on work he and several other researchers have conducted to consider varying the fiber orientation continuously within the structure to compensate for local or global geometric features, or to better accommodate particular loads. An example is illustrated below, where instead of using straight fiber trajectories to resist axial buckling in a noncircular cylinder, as on the left, the fiber trajectories are a function of circumferential location in an effort to mitigate the effects of the noncircular geometry, as on the right. Formally stated, within a layer of fiber-reinforced material the direction of material orthotropy varies continuously with the circumferential coordinate. The challenge is to determine the manner in which the orientation varies so as to maximize load capacity P.