Accession Number:

ADA090495

Title:

Experimental Random Fatigue in Elastic-Plastic Range - Models of Significant Variables.

Descriptive Note:

Technical rept. 1978-1979,

Corporate Author:

WISCONSIN UNIV-MADISON DEPT OF ENGINEERING MECHANICS

Personal Author(s):

• Huang,T. C.
• Nagpal,Vinod K.

Report Date:

1979-09-01

Pagination or Media Count:

28.0

Abstract:

In the previous study of first order models with 11 variables to predict fatigue life of materials in elastic-plastic range under random vibrations, 5 variables showed significant effects. In this report both first and second order models based on 5 significant variables have been developed. The tables of analysis of variance, and of the predicted lives together with residuals and 95 confidence intervals, are constructed for each model. Based on 24 tests a second order model of 5 significant variables consisting of 10 terms is found to be the best one. The deviations of the lives predicted by this model ranged from -34.3 to 17.4 with an average of 8.32 on the negative side and 6.35 on the positive side. These results contrast with those which are obtained by the principle of linear damage accumulation and cycle counting and involve several hundred percent error as a rule. Author

Descriptors:

• *MATHEMATICAL MODELS
• *FATIGUE LIFE
• *MATERIALS
• *DEFORMATION
• *MATHEMATICAL PREDICTION
• EXPERIMENTAL DATA
• RANDOM VARIABLES
• ELASTIC PROPERTIES
• ANALYSIS OF VARIANCE
• PLASTIC PROPERTIES
• FACTORIAL DESIGN

Subject Categories:

• Statistics and Probability
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE