Accession Number : ADP000018

Title :   An Efficient Method for Determining the 'A' and 'B' Design Allowables,

Corporate Author : ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MA

Personal Author(s) : Neal,Donald ; Spiridigliozzi,Luciano

Report Date : SEP 1982

Pagination or Media Count : 57

Abstract : Suggested statistical procedures for obtaining material 'A' and 'B' allowables from both complete and censored samples are outlined in this paper. The allowables represent a value determined from a specified probability of survival with a 95% confidence in the assertion. The survival probabilities are .99 for the 'A' allowables and .90 for the 'B' allowables. Both parametric and non-parametric statistical models are evaluated with respect to their desirability in obtaining the allowables. Exploratory data analysis procedures are introduced in order to determine acceptable distribution functions for representing the data in addition to recognizing outliers (bad data) or multi-modality. It is demonstrated from a variety of materials test data that allowable determinations require prior application of exploratory data analysis procedures in order to assure acceptable results.

Descriptors :   *Statistical analysis, *Mathematical models, *Composite materials, *Stresses, Weibull density functions, Monte Carlo method, Numerical analysis, Equations, Wave equations, Failure(Mechanics), Strength(Mechanics), Statistical data, Free radicals, Distribution functions, Experimental data, Graphs

Subject Categories : Laminates and Composite Materials
      Statistics and Probability
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE