NUMERICAL METHOD FOR SENSITIVITY ANALYSIS OF EIGENSYSTEMS WITH NON-REPEATED AND REPEATED EIGENVALUES

1996 ◽  
Vol 195 (1) ◽  
pp. 17-32 ◽  
Author(s):  
I.-W. Lee ◽  
G.-H. Jung ◽  
J.-W. Lee
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Method ◽  
Repeated Eigenvalues

Design Sensitivity Analysis of Structure-Induced Noise and Vibration

1997 ◽  
Vol 119 (2) ◽  
pp. 173-179 ◽  
Author(s):  
K. K. Choi ◽  
I. Shim ◽  
S. Wang
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Method ◽  
Variational Equation ◽  
Adjoint Operator ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Adjoint Variable ◽  
Element Analysis ◽  
Modal Frequency ◽  
Noise And Vibration

A continuum design sensitivity analysis (DSA) method for dynamic frequency responses of structural-acoustic systems is developed using the adjoint variable and direct differentiation methods. A variational approach with a non-self-adjoint operator for complex variables is used to retain the continuum elasticity formulation throughout derivation of design sensitivity results. It is shown that the adjoint variable method is applicable to the variational equation with the non-self-adjoint operator. Sizing design variables such as the thickness and cross-sectional area of structural components are considered for the design sensitivity analysis. A numerical implementation method of continuum DSA results is developed by postprocessing analysis results from established finite element analysis (FEA) codes to obtain the design sensitivity of noise and vibration performance measures of the structural-acoustic systems. The numerical DSA method presented in this paper is limited to FEA and boundary element analysis (BEA) is not considered. A numerical method is developed to compute design sensitivity of direct and modal frequency FEA results. For the modal frequency FEA method, the numerical DSA method provides design sensitivity very efficiently without requiring design sensitivities of eigenvectors. The numerical method has been tested using passenger vehicle problems. Accurate design sensitivity results are obtained for analysis results obtained from established FEA codes.

NUMERICAL ANALYSIS OF SMART STRUCTURES WITH UNCERTAINTIES

2004 ◽  
Vol 01 (02) ◽  
pp. 227-239 ◽  
Author(s):  
S. VALLIAPPAN ◽  
C. K. CHEE
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Fuzzy Sets ◽  
Numerical Method ◽  
Smart Structures ◽  
Sensitivity Index ◽  
Material Parameters ◽  
Element Technique ◽  
Fuzzy Parameters

In this paper, a numerical method for the analysis of smart structures with uncertainties involved in the material parameters is presented. This method combines the finite element technique, concepts of fuzzy sets and optimization. For the optimization of fuzzy parameters, a sensitivity index is proposed. The sensitivity analysis based on the proposed sensitivity index can be effectively used to reduce the number of variables to be fuzzified and thus reducing the computational efforts considerably.

Reliability Analysis of CFD Solution Using Sensitivity Theory

2003 ◽  
Author(s):  
Nobuatsu Tanaka ◽  
Yasunori Motoyama
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Solution ◽  
Numerical Method ◽  
Reliability Analysis ◽  
Numerical Models ◽  
The Other ◽  
Reference Case ◽  
Strict Solution ◽  
Sensitivity Theory ◽  
Additional Calculation

In this study, we present a new numerical method to quantitatively analyze the reliability of numerical models by using the sensitivity theory. If a reference case of typical parameters is once calculated with the method, no additional calculation is required to estimate the results of the other numerical parameters such as more detailed solutions. Furthermore, we can estimate the strict solution from the sensitivity analysis results and can quantitatively evaluate the reliability of the numerical solution by calculating the numerical error.

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