Accession Number:

ADA517625

Title:

Finer-Optic Strain Monitoring on a Navy Cruiser

Descriptive Note:

Journal article

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC OPTICAL SCIENCES DIV

Report Date:

2008-01-01

Pagination or Media Count:

4.0

Abstract:

A number of CG class vessels in the U.S. Navy are experiencing cracking at various locations on the aluminum superstructure. The cracking has been observed on the 04 level deckplate, the overhead of one of the ANSPG-62 Illuminator radar rooms, the intake bulkhead, and several other locations on one particular class of vessel. The cracking is, in many cases, persistent, recurrent even after repairs, and has the potential to influence mission critical operations aboard ships. Currently, the cause of this cracking has been investigated and is believed to be stress corrosion caused by sensitization of the aluminum alloy used in construction 5456 material. However, in order for this type of cracking to initiate and persist, the material must be sustaining large stresses. The origin of these stresses is still in question. The goal of this work was to instrument one of the affected areas, monitor the stresses over a 36-hour period during transit, and try to discern the types of ship maneuvers or ambient conditions that are leading to stress concentrations. The specific area under observation was the deckplate overhead of the 4 Radar room 05-316-0-C onboard a ship from the affected class. This location was chosen because there has been repeated cracking of this deckplate and because this room provided the most convenient, unobstructed location for installation.

Subject Categories:

  • Properties of Metals and Alloys
  • Test Facilities, Equipment and Methods
  • Mechanics
  • Marine Engineering
  • Structural Engineering and Building Technology
  • Naval Surface Warfare

Distribution Statement:

APPROVED FOR PUBLIC RELEASE