Impact response of graphite-epoxy flat laminates using projectiles that simulate aircraft engine encountersAn investigation of the response of a graphite-epoxy material to foreign object impact was made by impacting spherical projectiles of gelatin, ice, and steel normally on flat panels. The observed damage was classified as transverse (stress wave delamination and cracking), penetrative, or structural (gross failure): the minimum, or threshold, velocity to cause each class of damage was established as a function of projectile characteristics. Steel projectiles had the lowest transverse damage threshold, followed by gelatin and ice. Making use of the threshold velocities and assuming that the normal component of velocity produces the damage in nonnormal impacts, a set of impact angles and velocities was established for each projectile material which would result in damage to composite fan blades. Analysis of the operating parameters of a typical turbine fan blade shows that small steel projectiles are most likely to cause delamination and penetration damage to unprotected graphite-epoxy composite fan blades.
Document ID
19750041160
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Preston, J. L., Jr.
Cook, T. S. (United Aircraft Corp. Pratt and Whitney Aircraft Div., Middletown, Conn., United States)
Date Acquired
August 8, 2013
Publication Date
January 1, 1975
Subject Category
Composite Materials
Meeting Information
Meeting: Foreign object impact damage to composites; Symposium