EFFECTS OF FIBERGLASS ON RESIDUAL STRENGTH AND DAMAGE MITIGATION IN UNIDIRECTIONAL CARBON FIBER LAMINATE COMPOSITES

Author

John Patrick Burgelin, Southern Illinois University CarbondaleFollow

Date of Award

1-1-2009

Degree Name

Master of Science

Department

Civil Engineering

First Advisor

Yen, Shing-Chung (Max)

Abstract

The purpose of this study was to determine the effects, if any, of including varying amounts of fiberglass in Unidirectional Carbon Fiber Laminates. The focus was on strength, weight, and damage. A solution to the entrapment of air in thick unidirectional carbon fiber laminates under vacuum pressure was expected from this study. This study presents background, introduction, data, and results pertaining to the subject. Care was made to fully explain all procedures and terminology for complete comprehension of the subject matter. This study used Design of Experiments to formulate an adequate test population, and it used multiple specimens per Case to formulate an accurate representation of the results. This study used empirical results calculated from Compression After Impact data gathered on a Instron model 5585H at NRRI with a CAI frame, and a load cell capable of 56,250lbs, using Bluehill software for data collection, as well as results determined from nondestructive inspection using a PE + Pulse Echo ultrasonic machine, specifically a Flawinspecta from Diagnostic Sonar LTD with 128 element 67mm array and Flawinspecta version 1.3.6 software. A focus of this research was to create a method to manufacture thick unidirectional carbon fiber laminates solely under vacuum pressure. Currently the only way to manufacture suitable thick unidirectional laminates is through use of an autoclave; otherwise an abundance of entrapped air structurally weakens the part and will result in an inadequate specimen. This entrapped air not only weakens the piece by interrupting the stress handling characteristics of the fiber-matrix structure, but makes it near impossible to use ultrasound as a nondestructive inspection option to check for inconsistencies in the material. The second focus of the research was to understand the effects, if any of including fiberglass within a carbon composite panel. Both dry fiberglass veil and pre-preg fiberglass fabric were included in various samples to view any effects on strength, and damage tolerance. The samples were compared on thickness or bulk, weight, residual strength, and damage mitigation. Disclaimer: Certain information such as: Sources, Technical Data, Specific Names, etc. must be withheld due to Classification, and Business Interests.