MICROSTRUCTURAL OPTIMIZATION OF FUNCTIONALLY GRADED COMPOSITES SUBJECTED TO A THERMAL-GRADIENT VIA THE COUPLED HIGHER-ORDER THEORY

A recently developed higher-order theory for the response of a functio nally graded composite plate subjected to a through-thickness thermal gradient is employed to optimize the composite's microstructure. The h igher-order theory explicitly couples the microstructural and macrostr uctural effects, thereby providing a rational methodology for analyzin g the response of functionally graded materials, typically analyzed us ing the standard uncoupled micromechanics approach, which often produc es erroneous results. Herein, the higher-order theory is incorporated into an optimization algorithm to determine optimal through-thickness distributions of the reinforcement phase in a composite plate subjecte d to a thermal gradient that minimize the inplane moment resultant, an d thus the tendency of the plate to bend about an axis. The results in dicate that the manner of constraining the plate from bending due to t he thermal gradient is a major factor that governs the optimal reinfor cement phase distributions. (C) 1997 Elsevier Science Limited.