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Flexural stiffness design using Miki’s diagram. Flexural lamination parameters Boundaries of the domain What laminates have the same position on the Miki in-plane diagram as on the Miki flexural diagram?. Examples. (0/90) s : , h=4t ,. Stiffest laminate under lateral loads.
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Flexural stiffness design using Miki’s diagram • Flexural lamination parameters • Boundaries of the domain • What laminates have the same position on the Miki in-plane diagram as on the Miki flexural diagram?
Examples • (0/90)s : ,h=4t • ,
Stiffest laminate under lateral loads • Recall displacement under sine load • To find stiffest laminate we need to maximize S= • From Table 2.1 • This implies that S is a linear function of the lamination parameters, and the stiffest laminate is an angle ply. Why?
Example 8.2.1a • Design a 16-layer 20x15” laminated graphite epoxy plate to maximize its fundamental frequency. Material properties are: • Tsai-Pagano material properties (in Msi) are
Normalized fundamental frequency • Normalized frequency • For our data • For maximum frequency we want negative and negative , so angles near 60-deg. • Why?
Maximization of frequency • Iso-frequency contours on Diagram. • Maximum where iso-frequency line is tangent to diagram • Get • Text suggests • Can we do better? Should be omega21 in figure