Dynamic response of multidirectional composites in hygrothermal environments

The present paper deals the effects of temperature and moisture on the free vibration and transient response of multidirectional composites. A three-dimensional finite element analysis procedure is developed using 20 noded isoparametric quadratic elements. The analysis accounts for the degradation of composite properties due to both temperature and moisture concentration. A typical multidirectional unit cell is assumed to consist of several unidirectional composite blocks. The transformation based relationships are used to generate the stiffness properties of multidirectional composite plates. The numerical results for the natural frequencies and transient response of multidirectional composites under the action of both temperature and moisture concentration are presented and discussed.