Skip to content

Latest commit

 

History

History
36 lines (26 loc) · 2.66 KB

README.md

File metadata and controls

36 lines (26 loc) · 2.66 KB

These are tools I wrote while doing some work with rheological spectra.

specgen.m

specgen.m is a matlab script that generates a discrete rheological spectrum with error according to the method in Honerkamp and Weese [2].

ToDo

  • The RNG might not produce the same error between runs. It's unclear if this is desirable anyway, but I should at least be clear about it.
  • Currently I integrate the spectrum numerically, but it can in fact be done exactly and I don't know why I didn't do this.
  • More realistic error might be generated according to the methods in section D of Anderssen and Davies [3].
  • I dislike Matlab, but I may need to make some changes to make it an idiomatic octave script.

spectrumcalc

spectrumcalc is a perl script that takes a discrete rheological spectrum and a list of points, and calculates relevant material functions at those points. If the input spectrum is a relaxation spectrum, then the points are interpreted as frequencies and dynamic moduli will be calculated. If the input spectrum is a retardation spectrum, then the points are interpreted as times, and creep compliances will be calculated. An overview of these calculations can be found in many books, but my favorite is Ferry [4].

McDougall-Orbey-Dealy

Contains 2 data files (plain text, tab separated). These are the data used in [1].

  • "synmod.dat" contains the simulated dynamic modulus data in three columns: ω, G'(ω), G"(ω).
  • "synH.dat" contains the simulated relaxation spectrum in two columns: τ, H(τ). This was used for intermediate calculations and plotting.

Honerkamp-Weese

Contains 1 data file (plain text, tab separated). These data are published in [2].

  • "Table1.dat" contains the simulated dynamic modulus data in three columns: ω, G'(ω), G"(ω).

References

[1] Inferring meaningful relaxation spectra from experimental data
McDougall, Ian and Orbey, Nese and Dealy, John M., Journal of Rheology (1978-present), 58, 779-797 (2014), DOI:http://dx.doi.org/10.1122/1.4870967

[2] Determination of the relaxation spectrum by a regularization method
J. Honerkamp and J. Weese, Macromolecules, 1989, 22 (11), pp 4372-4377, DOI:http://dx.doi.org/10.1021/ma00201a036

[3] Simple moving-average formulae for the direct recovery of the relaxation spectrum
Anderssen, R. S. and Davies, A. R., Journal of Rheology (1978-present), 45, 1-27 (2001), DOI:http://dx.doi.org/10.1122/1.1332787

[4] Viscoelastic Properties of Polymers, 2nd ed.
J. D. Ferry; Wiley: New York, 1970 (current edition is 3rd: see here)