Determination of Nonlinear Viscoelasticity Parameters for Polymeric and Composite Materials by Numerical Methods,
Abstract
A Taylor extension of the power law for nonlinear creep and recovery behaviour of polymeric materials was performed. Upon variation of these equations with respect to the parameters a least square method in conjunction with an iterative approach was used to determine the desired parameters. The iteration is stopped after the standard deviation of all 'experimental points' reaches a minimum value. The 'experimental points' were artificially generated by using random numbers which were normally distributed around the theoretical functional values within a present error band. For each mean error point of a particular parameter 10 different runs were made, such that every time a new set of random numbers was chosen. Thus it was possible to study the sensitivity and the limitations of an experimental approach for determining the nonlinear viscoelastic parameters of the power law representation, derived by Schapery from thermodynamical principles. The same approach would apply to any other form of the creep function which can be expanded into a Taylor series.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 04, 1983
- Accession Number
- ADA145311
Entities
People
- D. J. Land
- J. M. Augl
Organizations
- Naval Ordnance Laboratory