PhD Research Proposal

Powder reinforced composites are more are less isotropic. Fibre reinforced composites are anisotropic, which is an advantage in that one can tailor make propeties to suit the application.
Any PhD level study of composites will require considerable laboratory and computational facilities.
Are you looking for any specific application (like propellers, turbine blades and such) or specific kind of vibration (like torsion)?

There is a lot of published info in this field.
These two publications may give you some idea of studies being done on the effect of stacking on properties.

The Effect of Fiber Orientation and Laminate Stacking Sequences on the Torsional Natural Frequencies of Laminated Composite Beams:
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Stacking of composites is a rather specialized area. You may have to discuss with your guides and experts in the field to formulate a PhD problem in detail.