Accession Number:

ADP006814

Title:

Damage Progression Under Compressive Loading in Composite Laminates Containing an Open Hole,

Descriptive Note:

Corporate Author:

NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) INST FOR AEROSPACE RESEA RCH

Report Date:

1992-04-01

Pagination or Media Count:

16.0

Abstract:

This paper describes an experimental investigation into damage progression in compressively loaded quasi-isotropic laminates with a circular hole and the prediction of damage initiation using 3D finite element failure analysis. Notched laminated plates were fabricated from Narmco IM65245C with three stacking sequences 4504590sub 6s, 45sub 30sub 3-45sub 390sub 3sub 2S, AND 456Osub 6-45sub 690sub 6sub s. Most specimens were tested to ultimate failure but some were stopped prior to failure. The criterion for stopping the test was the detection of audible acoustic emission. The tests revealed that the notched strength decreased as the ply group thickness increased. An examination of the hole surface of those specimens not taken to ultimate failure revealed delaminations at the 45 deg C deg and -45 degO deg interfaces and failure of the 45 deg and 0 deg ply groups. For the specimen where six plies with the same fibre orientation were grouped, the midplane of the O deg ply group also contained a delamination. A tensor polynomial failure criterion which used all the six stress states determined from the 3D finite element analysis at the laminate characteristic dimension was used to predict initial laminate failure.

Subject Categories:

  • Laminates and Composite Materials
  • Aircraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE