Accession Number:

ADA209150

Title:

Composite Material Repair and Reliability

Descriptive Note:

Master's thesis

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1989-03-01

Pagination or Media Count:

160.0

Abstract:

Composite structure repair methodology has been developed to specific applications typically in small area and limited to secondary structure and is being extended to Large Area Composite Structure Repair with target extension to primary structures. Therefore, the repair becomes more critical because we get redistribution of stresses that can also affect the zones outside of the repair area. For this reason, an analytic evaluation of the repairs reliability has to be performed to define a parameter which reflects on the effectiveness of the repair. In this work, we establish a principal guideline to evaluate the redundancy and compare the reliability of the repair to the reliability of the parent structure i.e., the structure in the undamaged state. The approach adopted is to utilize structural finite element analysis to compute the state and of the candidate repaired state. The reliability of these two spatially non- uniform stresses is computed by a probabilistic failure criterion. Thus, we can optimize the repair configuration by varying the strength and the stiffness of any element in the repair site by varying the lamination angles, and selectively using hybrid materials.

Subject Categories:

  • Attack and Fighter Aircraft
  • Laminates and Composite Materials
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE