A COMPARISON OF MODAL EXPANSION AND TRAVELLING WAVE METHODS FOR PREDICTING ENERGY FLOW IN BEAM STRUCTURES

The validity of the application of energy flow analysis for beam structures under random excitations is investigated in this paper. The approximate solutions of energy density and intensity in a beam subject to random loadings are obtained by solving the governing equation of random energy flow analysis using Fourier transform technique. The formulations of the exact energy density distribution and intensity in the beam are derived using the classical modal analysis method. For a simply supported beam subject to distributed or concentrated random excitations, the validity of random energy flow analysis is investigated through comparisons between solutions obtained from the approximate and exact methods for energy response as well as intensity. The results indicate that, the mode count of the analysis frequency band, which means the number of modes involved in the band, is the key factor affecting the prediction accuracy of random energy flow analysis, and that if the mode count of the band is sufficiently large, random energy flow analysis can provide rather accurate estimates for both energy density and intensity in a wide frequency range.

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MT–HVdc Systems Fault Classification and Location Methods Based on Traveling and Non-Traveling Waves—A Comprehensive Review

Applied Sciences ◽

10.3390/app9224760 ◽

2019 ◽

Vol 9 (22) ◽

pp. 4760 ◽

Cited By ~ 4

Author(s):

Raheel Muzzammel ◽

Ali Raza ◽

Mohammad Rashid Hussain ◽

Ghulam Abbas ◽

Ishtiaq Ahmed ◽

...

Keyword(s):

Research Paper ◽

Travelling Wave ◽

Fault Classification ◽

Transmission Network ◽

Grounding Resistance ◽

Hvdc Transmission ◽

High Voltage Direct Current ◽

Detailed Mathematical Analysis ◽

Wave Methods ◽

Location Methods

Estimation of fault classification and location in a multi-terminal high voltage direct current (MT–HVdc) transmission system is a challenging problem and is considered to be a fundamental maneuver of dc grid protection. This research paper critically reviews traveling and non-travelling wave methods of classification and location of dc faults in multi-terminal HVdc transmission systems. Detailed mathematical analysis of MT–HVdc systems composed of high grounding resistance, cable and overhead line segments, and bipolar coupled transmission network under healthy and faulty conditions, are evaluated. The gravity of this research paper addresses benefits and shortcomings of traveling and non-traveling wave methods and futuristic techniques of fault classification and location.

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Vibrational Energy Flow Analysis of Corrected Flexural Waves in Timoshenko Beam – Part II: Application to Coupled Timoshenko Beams

Shock and Vibration ◽

10.1155/2006/562762 ◽

2006 ◽

Vol 13 (3) ◽

pp. 167-196 ◽

Cited By ~ 23

Author(s):

Young-Ho Park ◽

Suk-Yoon Hong

Keyword(s):

Timoshenko Beam ◽

Energy Flow ◽

Vibrational Energy ◽

Flow Analysis ◽

Companion Paper ◽

Wave Transmission ◽

Classical Solutions ◽

Flexural Waves ◽

Beam Structures ◽

Energy Flow Analysis

This paper presents the methodology for the energy flow analysis of coupled Timoshenko beam structures and various numerical applications to verify the developed methodology. To extend the application of the energy flow model for corrected flexural waves in the Timoshenko beam, which is developed in the other companion paper, to coupled structures, the wave transmission analyses of general coupled Timoshenko beam systems are performed. First, power transmission and reflection coefficients for all kinds of propagating waves in the general, coupled Timoshenko beam structures are derived by the wave transmission approach. In numerical applications, the energy flow solutions using the derived coefficients agree well with the classical solutions for various exciting frequencies, damping loss factors, and coupled Timoshenko beam structures. Additionally, the numerical results for the Timoshenko beam are compared with those for the Euler-Bernoulli beam.

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