Accession Number:

AD0631351

Title:

INSPECTION PERIODS DETERMINED FROM DATA OF CRACK DEVELOPMENT AND STRENGTH REDUCTION OF AN AIRCRAFT STRUCTURE USING STATISTICAL METHODS FOR DESIGNING AIRCRAFT WITH RESPECT TO FATIGUE.

Descriptive Note:

Technical note,

Corporate Author:

AERONAUTICAL RESEARCH INST OF SWEDEN STOCKHOLM

Personal Author(s):

Report Date:

1961-06-01

Pagination or Media Count:

29.0

Abstract:

Regular inspections of an aircraft structure might form a very effective means of providing an adequate safety level when the inspection periods are determined by statistical analysis. If it is assumed that a crack of a certain minimum length, is always detected at the inspections, it is possible to calculate the probability of collapse of the structure for any inspection period and limit life of the structure, provided the load spectrum, the time to critical-crack initation, as well as the crack propagation and the corresponding reduction of the ultimate strength, are known from experimental investigations. Using such data available in the literature, numerical evaluations have been made, assuming various stress levels and inspection periods. From the results, the appropriate inspection periods are determined and compared with the crack propagation time to final failure. The approximations introduced in the statistical analysis, are discussed, and suggestions are made for future theoretical and experimental investigations. Author

Subject Categories:

  • Aircraft
  • Statistics and Probability
  • Manufacturing and Industrial Engineering and Control of Production Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE