Evaluation of Aircraft Structural Repair/Analysis Codes

Abstract

Abstract : This study evaluates existing structural integrity analysis methods for the repair of aircraft structures, primarily focusing on composite (patch) to metal surface structures. This research was necessitated by the growing need to keep current aircraft in service well beyond their normal design lives. When defects are discovered during inspections the components must be either repaired or replaced. In most instances, it is not economically feasible to replace entire components. Therefore, repairing the damaged area(s) is usually preferred and critical. Additionally, repairs must be made quickly so that the aircraft may be returned to service as soon as possible. The results generated in this study evaluate the status of various repair analysis codes, determine which tools are potentially the most useful to ALC engineers, and provide information to assist Wright Laboratory engineers in deciding whether these codes address current and future US Air Force requirements. However, this evaluation does not intend to 'recommend' or 'disapprove' the use of any one software or methodology to Air Force, government or contractor personnel. Also, this evaluation of the composite repair/analysis codes relates solely to the versions that were available during the evaluation period of July 95 to 28 Feb 96. This report program covers the determination of ALC requirements, a review of current repair/analysis codes, the determination of equivalent capability, and an evaluation of repair/analysis codes.