Accession Number : ADA180456

Title :   Damping Characteristics of Metal Matrix Composites.

Descriptive Note : Quarterly letter progress rept. no. 5, 10 Dec 86-8 Apr 87,

Corporate Author : MARTIN MARIETTA AEROSPACE DENVER CO

Personal Author(s) : Misra, Mohan S.

Report Date : 08 APR 1987

Pagination or Media Count : 6

Abstract : Summary of Work Accomplished Damping Behavior of Germanium Alumina Composites, i) Developed damping test techniques to obtain reliable measurements with metal matrix composites Metal Matrix Composites in flexural and extensional modes of vibration between 1 x ten to the minus six and 800 ten to the minus six strain amplitude levels within 0.1 to 150 Hz frequency range. ii) At strain levels < ten to the minus five, specific damping capacity (psi) of P55Gr/6061A1 was amplitude independent and lower than values of the aluminum matrix. iii) Damping behavior at these strain levels (10 -5), is consistent with the values predicted by Hashin theory using damping properties of constituent fiber and matrix materials. iv) At strains > 10 -5, psi of P55Gr/6061A1 exhibited strain amplitude dependent behavior. In this strain amplitude region, the average psi value was higher than the psi values for the aluminum matrix, particularly in the extensional mode of vibration. Keywords: Frequency, Crystals, Strain rate.

Descriptors :   *DAMPING, *METAL MATRIX COMPOSITES, FLEXURAL PROPERTIES, STRAIN RATE, ALUMINUM, ALUMINUM OXIDES, AMPLITUDE, BEHAVIOR, CAPACITY(QUANTITY), COMPOSITE MATERIALS, CRYSTALS, FIBERS, GERMANIUM, LEVEL(QUANTITY), MATRIX MATERIALS, MEASUREMENT, RELIABILITY, STRAIN(MECHANICS), TEST METHODS, VIBRATION.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE