Use of a Simplified Model to Evaluate Lumbar Load Variability in Dynamic Testing of Transport Category Aircraft Seat Cushions

Details

• Creators:
  Moorcroft, David M.
• Corporate Creators:
  United States. Department of Transportation. Federal Aviation Administration. Civil Aerospace Medical Institute
• Corporate Contributors:
  United States. Department of Transportation. Federal Aviation Administration. Aircraft Certification Service
• Subject/TRT Terms:
  • Parts of seats
  • Seats
  • Foams
  • Loads
  • Dynamic tests
  • Aircraft
  • Lumbar Load
• Publication/ Report Number:
  DOT/FAA/AM-26/13
• DOI:
  https://doi.org/10.21949/1529735
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. Office of Aerospace Medicine. Civil Aerospace Medical Institute (CAMI)
• Abstract:
  The Federal Aviation Administration (FAA) requires that aircraft seating systems protect occupants in the event of an emergency landing. During the combined longitudinal-vertical impact, the seat bottom cushion significantly affects the loads transferred to the occupant's spine, and therefore the risk of injury. Previous testing revealed test-to-test lumbar load variability as high as 18%, which was hypothesized to arise in part from variation within foam material properties. In this study, a high-rate load frame was used to measure cushion force-deflection behavior, and those data were then used as inputs to a computational model to estimate the effect of cushion-property variability on predicted lumbar load. 13 credibility factors were used to support a determination that the model was adequate for answering the question of interest. While the loading curves varied by as much as 23%, the predicted peak lumbar load varied by no more than 7.4%. These findings suggest that test uncertainty due solely to differences within cushion material properties is lower than that from other sources of uncertainty in full-scale sled tests.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93145/dot_93145_DS1.pdf
• File Type:
  [PDF - 4.39 MB]
• Collection(s):
  FAA Civil Aerospace Medical Institute
• Main Document Checksum:
  urn:sha-512:c1094cfafa1bff852e5da1a2190695cbdaea866b8c8f64cf8eb6dda113e1d9b3fe853c027188696ce204dec1458ab74911730d048a3962c600c4b419705e2375