An Experimental Study of Fluid Structure Interaction of Carbon Composites under Low Velocity Impact

Abstract

The effect of fluid force on the natural frequencies and damping ratios of vibrating structures in contact with fluid is known as the Fluid Structure Interaction (FSI) problem. It can be interpreted as an added mass to the vibrating structure in the analysis of the dynamic response. Because the density of water is much greater than air, the added mass effect becomes even more critical in understanding the dynamic response of composites in water surroundings. In this study, experimental testing was carried out to investigate FSI of composite laminates immersed in fluid and subjected to low-velocity impact. Square composite laminates of carbon fiber weave and vinyl ester resin of size 305 mm and 2.38 mm nominal thickness were subjected to low velocity impact loading, using a specially developed vertical drop-weight testing machine. The composite samples were fitted with gages to provide real-time information on strain levels generated during impact. Impact tests were performed on four side clamped laminates in air-backed, water-backed, and dry surroundings, and at various impact energies for investigation. The findings of this study will provide a better understanding for the use of composite materials in underwater structural applications where impact loading is expected.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2009
Accession Number
ADA514333

Entities

People

  • Angela C. Owens

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Carbon Fibers
  • Composite Material Fabrication
  • Composite Materials
  • Composite Structures
  • Data Acquisition
  • Dynamic Response
  • Fibers
  • Impact Tests
  • Laminates
  • Manufacturing
  • Materials
  • Materials Processing
  • Materials Science
  • Measurement
  • Mechanics
  • Resonant Frequency
  • Strain Gages

Fields of Study

  • Materials science

Readers

  • Reinforced Composite Materials
  • Structural Dynamics.
  • Structural Health Monitoring of Composite Structures.