Accession Number : ADA306037

Title :   Dynamic Response of Damaged Angleplied Fiber Composites.

Descriptive Note : Technical memo,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Chamis, C. C. ; Sinclair, J. H. ; Lark, R. F.

PDF Url : ADA306037

Report Date : DEC 1979

Pagination or Media Count : 17

Abstract : An investigation was conducted to determine the effects of low level damage induced by monotonic load, cyclic load and/or residual stresses on the vibration frequencies and damping factors of fiber composite angleplied laminates. Two different composite systems were studied - low modulus fiber and ultra high modulus fiber composites. The results obtained showed that the frequencies and damping factors of angleplied laminates made from low modulus fiber composites are sensitive to low level damage while those made from ultra high modulus composites are not. Also vibration tests may not be sufficiently sensitive to assess concentrated local damage in angleplied laminates. And furthermore, dynamic response determined from low-velocity impact coupled with the Fast Fourier Transform and packaged in a minicomputer can be a convenient procedure for assessing low-level damage in fiber composite angleplied laminates. (MM)

Descriptors :   *VIBRATION, *LAMINATES, *FIBER REINFORCED COMPOSITES, *DAMPING, FINITE ELEMENT ANALYSIS, DYNAMIC RESPONSE, DAMAGE ASSESSMENT, FRACTURE(MECHANICS), GLASS FIBERS, RESIDUAL STRESS, FAST FOURIER TRANSFORMS, PREPREGS, CYCLIC LOADS, GRAPHITE EPOXY COMPOSITES.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE