Abstract
This thesis presents a method to correct for non-positive-definiteness in linear viscoelastic material functions. Viscoelastic material functions for anisotropic materials need to be interconverted in a matrix coefficient prony series form, with a requirement of positive definiteness. Fitting is usually done as a uniaxial prony series, resulting in scalar coefficients. When these uniaxial coefficients are placed in a coefficient matrix, the required positive definiteness cannot be guaranteed. For those matrices that do not meet this requirement, finding the nearest symmetric semi-positive definite form of the matrix results in a viable prony series matrix coefficient with the required positive definiteness. These corrected prony series coefficients allow for material functions to be interconverted with minimal changes to experimental data.
Thesis Completion
2020
Semester
Spring
Thesis Chair/Advisor
Kwok, Kawai
Degree
Bachelor Science in Aerospace Engineering (B.S.A.E.)
College
College of Engineering and Computer Science
Department
Mechanical and Aerospace Engineering
Degree Program
Aerospace Engineering
Language
English
Access Status
Open Access
Release Date
5-1-2020
Recommended Citation
Rehberg, Christopher D., "Ensuring Positive Definiteness in Linear Viscoelastic Material Functions Based on Prony Series" (2020). Honors Undergraduate Theses. 749.
https://stars.library.ucf.edu/honorstheses/749