scholarly journals Coupled Dynamics of Cable-Harnessed Structures: Experimental Validation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Karthik Yerrapragada ◽  
Armaghan Salehian
Keyword(s):  
Experimental Study ◽  
Partial Differential Equations ◽  
Frequency Response ◽  
Experimental Validation ◽  
Response Functions ◽  
Beam Structure ◽  
Coupled Dynamics ◽  
Coupled Partial Differential Equations ◽  
Offset Distance ◽  
Good Agreement

The experimental study and model validations for the coupled dynamics of a cable-harnessed beam structure are presented. The system under consideration consists of multiple pretensioned cables attached along the length of the host beam structure positioned at an offset distance from the beam centerline. Analytical model presented by the coupled partial differential equations (PDEs) for various coordinates of vibrations is found, and the displacement frequency response functions (FRFs) obtained for both Euler–Bernoulli and Timoshenko-based models are compared to those from the experiments for validation. The results are shown to be in very good agreement with the experiments.

scholarly journals On Solving One-Dimensional Partial Differential Equations With Spatially Dependent Variables Using the Wavelet-Galerkin Method

2013 ◽  
Vol 80 (6) ◽  
Author(s):  
Simon Jones ◽  
Mathias Legrand
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Galerkin Method ◽  
Frequency Response ◽  
Natural Frequencies ◽  
Basis Functions ◽  
Mode Shapes ◽  
Response Functions ◽  
Partial Differential ◽  
Frequency Response Functions

The discrete orthogonal wavelet-Galerkin method is illustrated as an effective method for solving partial differential equations (PDE's) with spatially varying parameters on a bounded interval. Daubechies scaling functions provide a concise but adaptable set of basis functions and allow for implementation of varied loading and boundary conditions. These basis functions can also effectively describe C0 continuous parameter spatial dependence on bounded domains. Doing so allows the PDE to be discretized as a set of linear equations composed of known inner products which can be stored for efficient parametric analyses. Solution schemes for both free and forced PDE's are developed; natural frequencies, mode shapes, and frequency response functions for an Euler–Bernoulli beam with piecewise varying thickness are calculated. The wavelet-Galerkin approach is shown to converge to the first four natural frequencies at a rate greater than that of the linear finite element approach; mode shapes and frequency response functions converge similarly.

Experimental Investigation of Ribbed Cylinder's Vibroacoustics Transmissibility

2012 ◽  
Vol 516-517 ◽  
pp. 714-717
Author(s):  
Zhi Yong Xie ◽  
Qi Dou Zhou ◽  
Deng Yuan Mo
Keyword(s):  
Frequency Response ◽  
Sound Radiation ◽  
Force Sensor ◽  
Dynamic Force ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Radiated Noise ◽  
Vibration And Sound Radiation ◽  
Force Calibration ◽  
Good Agreement

Exciting force's accurate measurement is crucial to the structure-born sound radiation. And the force sensor is calibrated by the dynamic force calibration equipment. Exciting force is accurately measured on the ribbed cylinder’s forced vibration and sound radiation. Based on the steady sine and random white noise exciting, the frequency response functions of the acceleration and sound pressure are obtained. Results obtained from the two methods are shown to be in good agreement with each other. According to the acceleration’s frequency response functions and sound pressure’s frequency response functions, it is obvious that the peak frequencies in the two frequency response functions are corresponding to each other. And the correspondence relationship could be used to help control the radiated noise.

scholarly journals Identification of relevant acoustic transfer paths for WT drivetrains with an operational transfer path analysis

2021 ◽  
Author(s):  
W. Schünemann ◽  
R. Schelenz ◽  
G. Jacobs ◽  
W. Vocaet
Keyword(s):  
Path Analysis ◽  
Wind Turbine ◽  
Frequency Response ◽  
Mechanical System ◽  
Reference Point ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Turbine Model

AbstractThe aim of a transfer path analysis (TPA) is to view the transmission of vibrations in a mechanical system from the point of excitation over interface points to a reference point. For that matter, the Frequency Response Functions (FRF) of a system or the Transmissibility Matrix is determined and examined in conjunction with the interface forces at the transfer path. This paper will cover the application of an operational TPA for a wind turbine model. In doing so the path contribution of relevant transfer paths are made visible and can be optimized individually.

Simulation and Experimental Study on Rear Frame Strength of Winch Lashing Car

2013 ◽  
Vol 819 ◽  
pp. 81-85
Author(s):  
Jing Tao Yue ◽  
Hui Pu ◽  
Xiang He Tao
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Experimental Validation ◽  
Evaluation Result ◽  
The Real ◽  
Element Simulation ◽  
General Transport

Heavy general transport vehicles are recommended as lashing points during rescue operations of winch. Taking SX2190 heavy transport vehicles frame as the experimental object, this paper introduces contents and methods of the test, and gets evaluation result of the rear frame through finite element simulation and experimental validation of the real frame-towing hook system for winch lashing car.

Calculation of Component Mode Synthesis Matrices From Measured Frequency Response Functions, Part 2: Application

1998 ◽  
Vol 120 (2) ◽  
pp. 509-516 ◽  
Author(s):  
J. A. Morgan ◽  
C. Pierre ◽  
G. M. Hulbert
Keyword(s):  
Frequency Response ◽  
Coupled System ◽  
Companion Paper ◽  
Component Mode Synthesis ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Measured Frequency ◽  
Measured Frequency Response ◽  
Coupled Beams ◽  
The Individual

This paper demonstrates how to calculate Craig-Bampton component mode synthesis matrices from measured frequency response functions. The procedure is based on a modified residual flexibility method, from which the Craig-Bampton CMS matrices are recovered, as presented in the companion paper, Part I (Morgan et al., 1998). A system of two coupled beams is analyzed using the experimentally-based method. The individual beams’ CMS matrices are calculated from measured frequency response functions. Then, the two beams are analytically coupled together using the test-derived matrices. Good agreement is obtained between the coupled system and the measured results.

Experimental Study for Extraction of Normal Modes

1995 ◽  
Author(s):  
S. Y. Chen ◽  
M. S. Ju ◽  
Y. G. Tsuei
Keyword(s):  
Frequency Response ◽  
Normal Mode ◽  
Normal Modes ◽  
Measurement Data ◽  
Mode Shapes ◽  
Complex Frequency ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Incomplete System ◽  
Coupled Structures

Abstract A frequency-domain technique to extract the normal mode from the measurement data for highly coupled structures is developed. The relation between the complex frequency response functions and the normal frequency response functions is derived. An algorithm is developed to calculate the normal modes from the complex frequency response functions. In this algorithm, only the magnitude and phase data at the undamped natural frequencies are utilized to extract the normal mode shapes. In addition, the developed technique is independent of the damping types. It is only dependent on the model of analysis. Two experimental examples are employed to illustrate the applicability of the technique. The effects due to different measurement locations are addressed. The results indicate that this technique can successfully extract the normal modes from the noisy frequency response functions of a highly coupled incomplete system.

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