A finite element numerical analysis is presented which models the influ ences of temperature variations and dilatations due to moisture absorption on the local stress state in a unidirectionally-reinforced composite material. These influences are admissible in both fiber and matrix, and all material properties are assumed to be temperature- and moisture-dependent. The fiber is assumed to be elastic and transversely isotropic, the matrix material inelastic and isotropic. A generalized plane strain condition is formulated, which permits the analysis of applied normal loadings in three directions (i.e., longitudinal and biaxial transverse) combined with arbitrary tempera ture and moisture content changes. Numerical results are presented for a typical graphite/epoxy composite, indicating the residual microstresses induced during cooldown from the curing temperature, and how they can be altered by a subsequent moisture absorption at room temperature. Results are also given for predicted microstress states and failure initiation in a graphite/epoxy composite modeled both with and without curing stresses and moisture dilatation, for a transverse normal applied loading continued beyond the elastic limit, to first failure.

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Many advances have been made during the last decade in the development and application of computational fluid dynamics (CFD), finite element analysis (FEA), numerical weather modeling, and other numerical methods as applied to the wind energy industry. The current information about this area of study may help researchers gage research efforts. Specifically, micro-siting, wind modeling and prediction, blade optimization and modeling, high resolution turbine flow modeling, support structure analysis, and noise prediction have been the main focuses of recent research. The advances in this area of research are enabling better designs and greater efficiencies than were possible previously. The trends toward system coupling, parallel computing, and replacing experiments are discussed. The shortcomings of recent research and areas of possible future research are also presented.

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