Abstract:
This thesis introduces new conforming and non-conforming finite elements for the
static and dynamic analysis of rotating composite layered plates and shells. The
elements consider parabolic distributions of transverse shear stresses, and based on
Lagrangian and Hermitian shape functions. They can deal with variable thickness
distributions as well as uniform distributions, and they are fully capable to deal with
rotating plate and shell structures, i. e. centrifugal stiffening and Coriolis force effects
are considered. Natural frequency analysis, forced vibration analysis, and flutter
analysis of composite layered plate and shell structures, employing those elements,
have been investigated. A computer programming package based on the developed
theory was designed, and it is machine independent and user friendly. A modular
approach was adopted in the package structure to allow any further development to
be considered. Efficient frontal solvers were adopted in the package for different
types of analysis. The developed package has been successfully validated on a main
frame computer (VAX), Unix workstations, and personal computers. Several case
studies were investigated and the results obtained were compared with corresponding,
published theoretical and/or experimental work. The package has proved to be a very
useful tool for the design optimization of composite layered plates and shells by
means of using different fibre angles for different layers so as to achieve the required
strength and/or stiffness.
