Accession Number:

ADA063654

Title:

Discussion of 'A Model of Fatigue Crack Growth in Polymers'.

Descriptive Note:

Technical rept.,

Corporate Author:

LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER

Report Date:

1978-12-28

Pagination or Media Count:

16.0

Abstract:

A model was previously proposed by Hertzberg, Skibo, and Manson to account for the sensitivity of fatigue crack growth rates to frequency. The model was based on the hypothesis that the mechanical Beta transition controls the fatigue deformation and on the use of time-temperature relationships to determine the match between the Beta transition frequency and temperature and the frequency and temperature of the test. An alternate model was recently proposed by Williams, who interpreted the frequency sensitivity in terms of the sensitivity of fracture toughness and Youngs modulus to frequency. In this communication, results of new experiments with nylon 66 are presented and discussed. Since Youngs modulus was independent of test frequency for nylon 66, and for several other polymers, it was concluded that the authors earlier hypothesis was not invalidated. Author

Subject Categories:

  • Plastics
  • Numerical Mathematics
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE