An Identification Technique for Damped Distributed Structural Systems Using the Method of Collocation
Report Number: WL-TR-91-3078 Volume III, p. GCA-1 thru GCA-12
Author(s): Chander, R., Meyyappa, M., Hanagud, S. V.
Corporate Author(s): Aerostructures, Inc., McDonnell Douglas Helicopter Co.
Laboratory: Wright Laboratory
Date of Publication: 1991-08
Pages: 12
DoD Task:
Identifier: This paper is part of a conference proceedings. See ADA241313
Abstract:
An identification scheme in the frequency domain, suitable for one-dimensional distributed structural dynamic systems with damping is considered. For this purpose, the form of a model representing the behavior of an Euler-Bernoulli beam is assumed to be known in the frequency domain. Also, the response of the system is assumed to be given at discrete locations along the beam. Quintic B-splines are then used to obtain a continuous representation of the response and its derivatives. The system parameters appearing in the governing differential equation are considered to be spatially varying functions. Cubic B-splines are used to approximate the parameter space, and their derivatives are obtained from such approximations. The method of collocation in conjunction with the equation error approach is then used to estimate the unknown parameters, which are the unknown coefficients of the parameter splines. A numerically simulated response of an Euler-Bernoulli beam in the presence of viscous damping is considered to validate the identification scheme. The estimated values of mass, stiffness and damping are discussed.
Author(s): Chander, R., Meyyappa, M., Hanagud, S. V.
Corporate Author(s): Aerostructures, Inc., McDonnell Douglas Helicopter Co.
Laboratory: Wright Laboratory
Date of Publication: 1991-08
Pages: 12
DoD Task:
Identifier: This paper is part of a conference proceedings. See ADA241313
Abstract:
An identification scheme in the frequency domain, suitable for one-dimensional distributed structural dynamic systems with damping is considered. For this purpose, the form of a model representing the behavior of an Euler-Bernoulli beam is assumed to be known in the frequency domain. Also, the response of the system is assumed to be given at discrete locations along the beam. Quintic B-splines are then used to obtain a continuous representation of the response and its derivatives. The system parameters appearing in the governing differential equation are considered to be spatially varying functions. Cubic B-splines are used to approximate the parameter space, and their derivatives are obtained from such approximations. The method of collocation in conjunction with the equation error approach is then used to estimate the unknown parameters, which are the unknown coefficients of the parameter splines. A numerically simulated response of an Euler-Bernoulli beam in the presence of viscous damping is considered to validate the identification scheme. The estimated values of mass, stiffness and damping are discussed.
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This report is part of the following conference:
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Proceedings of Damping '91: 13-15 February 1991 San Diego, California (GCA-1 through JCB-17)
WL-TR-91-3078 Volume III