MODIFICATION IN THE LAYUP SEQUENCE OF C SECTION SPAR TO AVOID THE CORNER RADIUS WRINKLE AND RESIN STARVATION BY PUTTING A UD PREPREG AS CAPPING PLY AT CORNER RADIUS

摘要

Composite material is consists of two or more materials combined on a macroscopic scale to form a new material that, if prope rly designed, exhibits the best qualities of its constituents material. The invention of the Composite material is considered as the one of the main invention after thermo jet engine in aero industry. Every raw material supplier of the composite material always pro vide its raw material processing cycle and designed parameter to obtain the most effective end product, with all physical, mechanical and chemical properties. In Practice it is noticed that in processing of thermosetting composite material the supplied design dat a are not always sufficient to get a final end product with design properties. There are many hidden and unhidden parameter in the processing of there composites material which impart a great impact on its design properties: These hidden and unhidden (supplier data) parameters which can be/ cant be controlled and controlled are classified as extrinsic parameter and intrinsic parameter. Many factors are there in the processing of the thermosetting composite like cure cycle, the dwell time and heating and cooling rate which can be control while many factor like resin viscosity, fiber and resin interaction at the high temperature are not controllable. In Invention, a unid irectional Carbon Prepreg is introduced at the outer corner radius of the C Section Spars. By implementing the carbon unidirectiona l Prepreg of the same resin system (epoxy) at the outer radius the resin starvation and wrinkle problem at the outer radius of the C section is avoided. Earlier in designed layup sequence for the C section spar the first layer in direct contact with the st eel tool is �45� while in invention the first layer is now unidirectional carbon layer which is in direct contact with steel tool and avoiding the resin starvation and carbon bidirectional layer wrinkle.