Inventors:
Ronald F. Gibson - Southfield MI
Emmanuel O. Ayorinde - Southfield MI
Assignee:
Wayne State University - Detroit MI
International Classification:
G01H 1300
Abstract:
Method and apparatus for deriving four independent elastic constants (longitudinal and transverse Young's moduli, in-plane shear modulus and major Poisson's ratio) of composite materials from the modal resonance data of a freely-supported rectangular thin plate made from the material. The method includes the steps of: suspending a panel of the material from a rigid support by a plurality of filaments having a low support stiffness which has minimal effect on motion of the panel; providing a vibration sensor to detect a vibration response in the panel; imparting an impulse to the panel; generating a response signal proportionate to the response in the panel to the impulse imparted; generating an excitation signal in proportion to the impulse; communicating the signals to an analyzer for transforming the signals into a frequency domain; deriving resonance frequencies and associated mode shape indices of the panel; communicating the resonance frequencies and the mode shape indices to a computing device; and predicting and displaying the elastic constants using the computing device.
