Measuring and testing – Vibration – Resonance – frequency – or amplitude study
Patent
1994-09-13
1996-07-09
Williams, Hezron E.
Measuring and testing
Vibration
Resonance, frequency, or amplitude study
73659, G01H 1300
Patent
active
055333990
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.
REFERENCES:
patent: 4342229 (1982-08-01), Massa
patent: 4412452 (1983-11-01), Biot et al.
patent: 4692615 (1987-09-01), Mensah et al.
patent: 4722223 (1988-02-01), Bach et al.
patent: 5150617 (1992-09-01), Schwarz et al.
patent: 5269181 (1994-12-01), Gibson et al.
James, D. W., Apparatus for Determining Dynamic Modulus of Elasticity And Internal Damping Capacity.
Date paper of "Durability of Polymer Based Composite Systems for Structural Applications".
L. R. Deobald & R. F. Gibson "Determination of Elastic Constants of Orthotropic Plates by a Modal Analysis/Rayleigh-Ritz Technique", Journal of Sound and Vibration (1988).
W. P. DeWilde et al "Determination of the Material Constants of an Anisotropic Lamina by Free Vibration Analysis", Proceedings of Second International Modal Analysis Conference, Orlando, Floria, I, 44-49 (1984).
H. Sol, et al "Durability of Polymer Based Composite Systems for Structural Applications", ANALATOM Inc., THE RESONALYSER (an article published on durability of polymer based composite systems for structural applications; requires preliminary tests on strips).
J. A. Wolf, Jr. & T. G. Came "Identification of the Elastic Constants for Composites Using Modal Analysis", Society for Experimental Stress Analysis, SESA Spring Meeting (1979).
"Test Procedures for Automotive Structural Composite Materials" Automotive Composites Consortium Materials Work Group (Jan. 1990).
"Improved Approximate Expressions for the Natural Frequencies of Isotropic & Orthotropic Rectangular Plates", Journal of Sound and Vibration, Academic Press Inc (London) (1985).
Ayorinde Emmanuel O.
Gibson Ronald F.
Ashraf Nashmiya
Wayne State University
Williams Hezron E.
LandOfFree
Method and apparatus for non-destructive measurement of elastic does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for non-destructive measurement of elastic , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for non-destructive measurement of elastic will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1859931