Development of a Design Procedure for Aeronautical Structures Based on Reliability

In this paper,an approach to aeronautica-structural design based on reliability analysis is presented.in this way, the concept of the level of safety is discussed and methods of its calculation are described using statistical data.based on the concept of the level of safety, a design procedure is proposed. in order to validate this design procedure, two design cases are studied. in the first case study, using the finite element method, a sandwich plate containing a circular disbond between the upper faceplate and core subjected to compressive in-plane load is examined. the calculated critical buckling load and its residual strength versus disbond diameter and design load versus level of safety are compared to the existing data and a good agreement is achieved. in the second case study, a delaminated sandwich beam under bending load is considered and the design load (obtained from the strain energy release rate analysis) versus level of safety is determined. the results of the study show that for the adopted visual inspection technique and a high probability of damage occurrence, the design load should be about 25%of the beam strength to achieve a reliability higher than 0.99.