Continuous relaxation spectra and its reduced-dimensionality descriptions for engineering design with linear viscoelasticity

by Lee, Yong Hoon, Corman, R. E., Ewoldt, Randy H. and Allison, James T.
Abstract:
Designing with rheologically-complex materials, in particular, linear viscoelastic fluids, requires a material description with parameters that are simple and uniquely represent material characteristics. In this study, we introduce a mathematical framework for the continuous relaxation spectra representation, and demonstrate that this material description is a design-appropriate and an independently-controllable material representation for linear viscoelasticity. Using continuous relaxation spectra in design offers the benefit of intrinsically limiting material design candidates to physically meaningful options. Next, we introduce a reduced-dimension representation of the continuous relaxation spectra representation for designers to aid interpretation of material design, providing valuable information for the material selection problem. This lower-dimensional representation is based on the integral moments of modulus-weighted spectra and their equivalence with viscosity-weighted spectra. To demonstrate how these concepts can be used in engineering system design, we solve simple test cases of design optimization problems using the continuous relaxation spectra representation and analyze the results using the reduced-dimension material representation. The design-appropriate material description and the reduced-dimension linear viscoelastic material representation supports enhanced intuition for designing with linear viscoelastic materials, which may help expand the appropriate use of these materials in engineering design.
Reference:
Yong Hoon Lee, R. E. Corman, Randy H. Ewoldt, James T. Allison, "Continuous relaxation spectra and its reduced-dimensionality descriptions for engineering design with linear viscoelasticity", in ASME 2019 International Mechanical Engineering Congress and Exposition, IMECE2019-13370, Salt Lake City, UT, USA, November 2019 (Extended Abstract).
Bibtex Entry:
@presentation{Lee2019IMECE,
    author = "Lee, Yong Hoon and Corman, R. E. and Ewoldt, Randy H. and Allison, James T.",
    title = "Continuous relaxation spectra and its reduced-dimensionality descriptions for engineering design with linear viscoelasticity",
    booktitle = "ASME 2019 International Mechanical Engineering Congress and Exposition",
    address = "Salt Lake City, UT, USA",
    year = "2019",
    month = nov,
    day = "11-14",
    number = "IMECE2019-13370",
%    pages = "",
    pdf = "http://hdl.handle.net/2142/106123",
%    doi = "",
    gsid = "12305661977906329171",
    comment = "Extended Abstract",
    abstract = "Designing with rheologically-complex materials, in particular, linear viscoelastic fluids, requires a material description with parameters that are simple and uniquely represent material characteristics. In this study, we introduce a mathematical framework for the continuous relaxation spectra representation, and demonstrate that this material description is a design-appropriate and an independently-controllable material representation for linear viscoelasticity. Using continuous relaxation spectra in design offers the benefit of intrinsically limiting material design candidates to physically meaningful options. Next, we introduce a reduced-dimension representation of the continuous relaxation spectra representation for designers to aid interpretation of material design, providing valuable information for the material selection problem. This lower-dimensional representation is based on the integral moments of modulus-weighted spectra and their equivalence with viscosity-weighted spectra. To demonstrate how these concepts can be used in engineering system design, we solve simple test cases of design optimization problems using the continuous relaxation spectra representation and analyze the results using the reduced-dimension material representation. The design-appropriate material description and the reduced-dimension linear viscoelastic material representation supports enhanced intuition for designing with linear viscoelastic materials, which may help expand the appropriate use of these materials in engineering design.",
}