Accession Number:

ADA361932

Title:

Mechanical Vibration Testing Results of Acoustic Test Panels

Descriptive Note:

Final rept.

Corporate Author:

NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD

Personal Author(s):

• Ratcliffe, Colin P.
• Crane, Roger M.

Report Date:

1998-12-01

Pagination or Media Count:

17.0

Abstract:

This report describes the mechanical vibration testing of two graphite reinforced composite plates. The plates were tested in a free-free boundary condition up to a frequency of approximately 6 kHz. The plates were designed to assess two different damping treatments. They consisted of a 1.37 inch thick carbon epoxy structural section with a 0.13 in thick region on one side for each treatment. One plate used a conventional constrained layer design, while the other used a thin free layer of fiber reinforced urethane. The results show that while the constrain layer damped plate has a higher energy dissipation potential, it also has a reduced stiffness. There is also some localized modal behavior, which suggests it may also be reduced in strength.

Descriptors:

• *MECHANICAL PROPERTIES
• *VIBRATION
• *STIFFNESS
• *DAMPING
• *ACOUSTIC PROPERTIES
• TEST AND EVALUATION
• STRUCTURAL PROPERTIES
• FIBER REINFORCED COMPOSITES
• DISSIPATION
• CARBON
• NAVAL EQUIPMENT
• GRAPHITE EPOXY COMPOSITES
• URETHANES

Subject Categories:

• Laminates and Composite Materials
• Acoustics
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE