INSPECTION PERIODS DETERMINED FROM DATA OF CRACK DEVELOPMENT AND STRENGTH REDUCTION OF AN AIRCRAFT STRUCTURE USING STATIC ANALYSIS
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 initiation, as well as the crack propagation and the corresponding reduction of the ultimate strength, are known from experimental investigations. Numerical evaluations have been made, assuming various stress levels and inspection periods. The appropriate inspection periods were 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)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1962
- Accession Number
- AD0278171
Entities
People
- Sigge Eggwertz
Organizations
- National Aeronautical Research Institute