Generation of spectra and stress histories for fatigue and damage tolerance analysis of fuselage repairs

Details

• Creators:
  Broek, D ; Smith, S H ; Rice, R C
• Corporate Creators:
  Battelle Memorial Institute. Columbus Laboratories ; John A. Volpe National Transportation Systems Center (U.S.)
• Subject/TRT Terms:
  Airframes Airplanes Fatigue Fuselages Maintenance Maintenance And Repair
• Publication/ Report Number:
  DOT-VNTSC-FAA-91-16
• Resource Type:
  Tech Report
• Edition:
  Final report; March 1990-May 1991
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration
• Abstract:
  This report describes a simplified procedure for the development of stress histories
  
  for use in the analysis of aircraft repairs.- Although repairs of all components of
  
  the airframe are of interest, this report concentrates on stress histories for
  
  fuselage skin repair, description of typical fuselage loadings is provided, and
  
  basic fuselage stress histories are described. A method for development of an
  
  exceedance diagram for analysis of fuselage skin repairs is detailed. Subsequently, a
  
  methodology for generating detailed stress histories is reviewed. Some of the key
  
  features are 1) the inclusion of a range of flights of different severities, 2) the
  
  inclusion of deterministic loads where they occur, e.g., ground-air-ground cycles, 3)
  
  the use of a near-optimum number of stress levels (10-16 positive and negative), 4)
  
  the combination of positive and negative excursions of equal frequency, and 5)
  
  matching of the total number of flights and cycles with the total exceedance diagram.
  
  Two methods of estimating fuselage skin stresses are presented, the first based on
  
  static equilibrium requirements and the second based on a limit load analysis.
  
  A comparison of the proposed history generation scheme with that of an airframe
  
  manufacturer for the KC-135 is also presented. The predicted fatigue crack growth
  
  patterns for a hypothetical through crack at a fastener hole are compared for the two
  
  history generation schemes at three areas within a fuselage. Predicted crack growth
  
  lives are within a factor of 1.5 for two of the three cases. For the third case
  
  (which is predicted to be the least severe by both techniques), the proposed scheme
  
  results in substantially longer crack growth life predictions. The probable reasons
  
  for these differences are discussed.
  
  
• Format:
  PDF
• Funding:
  DTRS-57-89-C-00006
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha256:90c0852420933bf827f0681950e17d5e9f5c46ba9eccf7cc557161292f68e366
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/9085/dot_9085_DS1.pdf
• File Type:
  [PDF - 1.62 MB ]