Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

The University of Maine

Theses/Dissertations

Anisotropy

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Mechanical Engineering

Determination Of The Viscoelastic Properties Of General Anisotropic Materials, Anish Sen Senan Jan 2003

Determination Of The Viscoelastic Properties Of General Anisotropic Materials, Anish Sen Senan

Electronic Theses and Dissertations

Elastic properties are rarely sufficient in order to evaluate the condition of a composite material. Knowledge of the viscoelastic properties is very critical for design purposes, for they directly characterize damping. Damping related measurements in the material provides information about the degree of cross-linking and crystallinity of the polymer. For metals, damping may be related to dislocation motion among other characteristics. For composite materials, in general the interphase and the matrix dominate the damping of the material. Ultrasonic measurement of damping gives a non- destructive measure of strength of composite materials. This thesis considers damping characteristics of polymer matrix composites …


Optimal Recovery Of Elastic Properties For Anisotropic Materials Through Ultrasonic Measurements, Miao Sun Jan 2002

Optimal Recovery Of Elastic Properties For Anisotropic Materials Through Ultrasonic Measurements, Miao Sun

Electronic Theses and Dissertations

Full knowledge of material elastic properties is required to facilitate design in many applications. The existence of misorientation between the geometric axes of the part and the material symmetry axes has in particularly created challenged in design of composite structure. In this thesis the potential for optimal identification of material symmetries for a general anisotropic material through a water immersion technique is explored. The concept is extensible to any class of symmetry groups and does not assume a-priori knowledge of the material. Initial experimental results for determining the elastic constants as well as locating the symmetry planes are presented. Many …