Sensitivity analysis of frequency response functions of composite sandwich plates containing viscoelastic layers

2010 ◽  
Vol 92 (2) ◽  
pp. 364-376 ◽  
Author(s):  
A.M.G. de Lima ◽  
A.W. Faria ◽  
D.A. Rade
Keyword(s):  
Sensitivity Analysis ◽  
Frequency Response ◽  
Sandwich Plates ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Composite Sandwich ◽  
Viscoelastic Layers ◽  
Composite Sandwich Plates

System Identification of Nonlinear Mechanical Systems Using Embedded Sensitivity Functions

2005 ◽  
Vol 127 (6) ◽  
pp. 530-541 ◽  
Author(s):  
Chulho Yang ◽  
Douglas E. Adams ◽  
Sam Ciray
Keyword(s):  
Sensitivity Analysis ◽  
System Identification ◽  
Frequency Response ◽  
Mechanical Systems ◽  
Rate Of Change ◽  
Response Functions ◽  
Vehicle Exhaust ◽  
Nonlinear Parameters ◽  
Frequency Response Functions ◽  
Sensitivity Functions

A novel method of experimental sensitivity analysis for nonlinear system identification of mechanical systems is examined here. It has been shown previously that embedded sensitivity functions, which are quadratic algebraic products of frequency response function data, can be used to identify structural design modifications for reducing vibration levels. It is shown here that embedded sensitivity functions can also be used to characterize and identify mechanical nonlinearities. Embedded sensitivity functions represent the rate of change of the response with variation in input amplitude, and yield estimates of system parameters without being explicitly dependent on them. Frequency response functions are measured at multiple input amplitudes and combined using embedded sensitivity analysis to extract spectral patterns for characterizing systems with stiffness and damping nonlinearities. By comparing embedded sensitivity functions with finite difference frequency response sensitivities, which incorporate the amplitude-dependent behavior of mechanical nonlinearities, models can be determined using an inverse problem that uses system sensitivity to estimate parameters. Expressions for estimating nonlinear parameters are derived using Taylor series expansions of frequency response functions in conjunction with the method of harmonic balance for periodic signals. Using both simulated and experimental data, this procedure is applied to estimate the nonlinear parameters of a two degree-of-freedom model and a vehicle exhaust system to verify the approach.

scholarly journals Sensitivity Analysis of Viscoelastic Structures

2006 ◽  
Vol 13 (4-5) ◽  
pp. 545-558 ◽  
Author(s):  
A.M.G. de Lima ◽  
M.H. Stoppa ◽  
D.A. Rade ◽  
V. Steffen Jr.
Keyword(s):  
Sensitivity Analysis ◽  
Frequency Response ◽  
Numerical Models ◽  
Complex Frequency ◽  
Response Functions ◽  
Viscoelastic Materials ◽  
Frequency Response Functions ◽  
Element Discretization ◽  
Analysis And Design ◽  
First Order

In the context of control of sound and vibration of mechanical systems, the use of viscoelastic materials has been regarded as a convenient strategy in many types of industrial applications. Numerical models based on finite element discretization have been frequently used in the analysis and design of complex structural systems incorporating viscoelastic materials. Such models must account for the typical dependence of the viscoelastic characteristics on operational and environmental parameters, such as frequency and temperature. In many applications, including optimal design and model updating, sensitivity analysis based on numerical models is a very usefull tool. In this paper, the formulation of first-order sensitivity analysis of complex frequency response functions is developed for plates treated with passive constraining damping layers, considering geometrical characteristics, such as the thicknesses of the multi-layer components, as design variables. Also, the sensitivity of the frequency response functions with respect to temperature is introduced. As an example, response derivatives are calculated for a three-layer sandwich plate and the results obtained are compared with first-order finite-difference approximations.

scholarly journals Finite element reduction strategy for composite sandwich plates with viscoelastic layers

2012 ◽  
Vol 16 (2) ◽  
pp. 473-480 ◽  
Author(s):  
Adriana Amaro Diacenco ◽  
Antônio Marcos Gonçalves de Lima ◽  
Edmilson Otoni Corrêa
Keyword(s):  
Finite Element ◽  
Sandwich Plates ◽  
Reduction Strategy ◽  
Composite Sandwich ◽  
Viscoelastic Layers ◽  
Composite Sandwich Plates

scholarly journals Dynamic analysis of laminated composite sandwich plates with a circular hole

2021 ◽  
Vol 1136 (1) ◽  
pp. 012050
Author(s):  
Deepak Kumar ◽  
Vinayak Kallannavar ◽  
Subhaschandra Kattimani ◽  
B. Rajendra Prasad Reddy
Keyword(s):  
Dynamic Analysis ◽  
Circular Hole ◽  
Laminated Composite ◽  
Sandwich Plates ◽  
Composite Sandwich ◽  
Composite Sandwich Plates

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.

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