Accession Number:

AD0876977

Title:

Evaluation of Sonic Methods for Inspecting Adhesive Bonded Honeycomb Structures,

Descriptive Note:

Corporate Author:

GENERAL AMERICAN TRANSPORTATION CORP NILES IL GENERAL AMERICAN RESEARCH DIV

Personal Author(s):

Report Date:

1970-08-01

Pagination or Media Count:

95.0

Abstract:

The relative merits of several commercially available portable field instruments, which utilize sonic and ultrasonic energy are presented. The capabilities of these instruments for nondestructive inspection of adhesively bonded metallic structures are demonstrated by presenting the test results obtained from inspecting a selected range of test samples. Each was intended to evaluate the instruments sensitivity to different structural effects honeycomb density changes, face sheet thickness variations, and laminated face sheets. In addition, several important attributes of each instrument are noted noise and background effect, scan rate, resolution, accuracy, ease of operation and detection of water in honeycomb. Each system has advantages in certain situations. For example, a combination pulse echo-contact impedence method yields the best resolutions for unbond detection. The eddy sonic method eliminates the need of a liquid couplant and provides improved inspection speed over the pulse echo and resonance methods. The low frequency 5 to 25 KHz resonance methods can be used to inspect structures having thick facing sheets. In addition, the advantages and capabilities are discussed. For ready reference the operating characteristics, apparent advantages and disadvantages, of each instrument are presented in tabular form. Author

Subject Categories:

  • Structural Engineering and Building Technology
  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE