Accession Number : ADA557890


Title :   An Enhanced Fuselage Ultrasound Inspection Approach for ISHM Purposes


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Ospina, Francisco


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a557890.pdf


Report Date : Mar 2012


Pagination or Media Count : 97


Abstract : This effort constitutes a systems engineering approach in which the materials science, ultrasound structural health monitoring, flight and maintenance operations, and relevant aeronautical policies and programs are involved to explore the evolution and characterization of structural cracks in aircraft fuselage structures in which the loads are varying. During flight, an aircraft fuselage skin and structure are subjected to varied cyclic loads, which can cause embedded cracks and other damage features to change their characteristics due to loading effects. The current research is based in the application of finite element modeling techniques using COMSOL and PZFLEX software to characterize the behavior of a crack under static loads as well as experimental techniques to observe the behavior of cracks under different static loads, with the goal of understanding the interaction of ultrasonic energy with opening-closing crack features. Specimen testing under tensile loads were considered, where crack detection and crack characterization were studied for bonded piezoelectric sensing and guided ultrasonic waves useful in structural health monitoring applications. The results suggest that crack detection and crack sizing accuracy can be impacted by load-induced, crack opening-closure effects, where linear elastic loading of the structure resulted in linear changes in the ultrasonic signal response.


Descriptors :   *STRUCTURAL HEALTH MONITORING , AIRCRAFT MAINTENANCE , FUSELAGES , SYSTEMS ENGINEERING , ULTRASONIC INSPECTION


Subject Categories : Aircraft
      Test Facilities, Equipment and Methods


Distribution Statement : APPROVED FOR PUBLIC RELEASE