Statistically Based Material Properties In Designing Aircraft Structures

Donald Neal, SRRC and Mark Vangel, Dana Farber

Key Words: Material Properties, Reliability, Material Strength, Composite Material Tolerance limits, Statistics, Structural Design

Abstract:

This paper describes statistical procedures and their importance in obtaining Composite material property values in designing structure for aircraft and military combat systems. The procedures and their order of operation are pre3sented with respect to their specific purpose. This includes: model identification, batch to batch variability recognition, outlier detection, and basis value computation. The property value is such that the strength exceeds this value with a prescribed probability with 95% confidence in the assertion. The survival probabilities are the 99^th percentile and the 90^th percentile for the A and B values respectively. The B values are the primary concern of this paper.