Structural Reliability Analysis

ABSTRACT: Aircraft structural risk and reliability analysis is a vital and growing element of the Unites State Air Force (USAF) Aircraft Structural Integrity Program (ASIP). As the age of the USAF inventory increases, the cumulative effects of structural repairs are an increasing threat to structural integrity. The current structural reliability software used by USAF has many shortcomings and cannot account for the diversity and complexity of structural repairs and cannot accurately predict the structural reliability for various repair scenarios. This software models the post-inspection condition of the structure as a repair crack size distribution only and has very limited application outside the over-sizing a fastener hole up to the second over-size. Furthermore, because the repair options for different airframe locations are different, the models for repairs and when/ where they are applied needs to be flexible so that the reliability analyst can accurately select which models to use in each situation. The overall objective of the proposed project is to develop a structural reliability analysis calculation tool that has the capability and flexibility to correctly model the physics of the variety of possible post-inspection structural repair options within the object-oriented modeling environment of the COTS software, SPISE. BENEFIT: Although the focus of the proposed activity is for USAF applications, the technology will have technical leverage which can be applied to other branches of armed-forces, Federal Aviation Administration (FAA), National Aeronautics and Space Administration (NASA), aerospace, airline industries, maritime and more. The tools to be developed and demonstrated during this project decreases the threat of cumulative effects of structural repairs to structural integrity of aircraft, spacecraft, and ship fleets and ensures safety and reliability of such fleetswith considerable benefits to both industry and the U.S. government.