Convergence acceleration of iterative modal reduction methods

Kim, Ki-Ook; Kang, Myung-Ku

doi:10.2514/3.14707

Cited by 15 publications

(4 citation statements)

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“…The response of total DOFs is presented by the specified responses (φ p '), using transformation matrix in the condensation method which described in Eq. (5). But, the transformation matrix generates error.…”

Section: Inverse Perturbation Based On the Condensation Methodsmentioning

confidence: 99%

Hierarchical Strategies of Optimization for Structural System Identification Based on the Condensation Method

Chang¹,

Baek²,

Cho³

2010

51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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In the system identification using finite element method (FEM), system responses of overall degree of freedoms (DOFs) are necessary. Because of the limitation of sensor and other experiment equipment, the responses of unspecified DOFs have to be contained in the design variables. This increase of the design variable makes difficult to solve the inverse problem. It is one of the solutions about the problem of limited responses that the responses of unspecified DOFs are represented by the responses of specified DOFs, using the condensation method. In the previous study, we applied iterative inverse perturbation method (IIPM) to enhance the efficiency and the solution convergence of the structural system identification problems using the condensation method. So we efficiently identify structural system through solving the optimization problem with design variables which have the same number of elements. However, if the size of problem developed to analyze practical model is increased, the number of design variables which had to be considered in solving process is extremely increased. To identify large structural system, optimization strategy to efficiently change design variables during the iteration of optimization is required. In this study, we suggest two optimization strategies which are adaptive sub-domain method and genetic concept method. Numerical examples are presented to verify the efficiency of the proposed methods and to compare with those methods.

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Section: Inverse Perturbation Based On the Condensation Methodsmentioning
confidence: 99%

Hierarchical Strategies of Optimization for Structural System Identification Based on the Condensation Method
Chang¹,
Baek²,
Cho³
2010
51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference
0
0
0
0
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“…The traditional research of rigid-flexible coupling modeling is mainly on the modal reduction method which the stiffness of flexible structure is expressed by the modal by finite element calculation in advance, but the method is limited because it can't solve the large deformation and the nonlinear problems [6][7][8]. Based on the MFBD technology, the modal reduction method is extended by using the node method which put the finite element analysis and multi-body dynamics analysis in the same solver, therefore it can directly obtain structure characteristics and effectively solve large deformation and nonlinear problems [9][10][11].…”

Section: Introductionmentioning
confidence: 99%

Rigid-flexible coupling dynamics simulation of planetary gear transmission based on MFBD
Hao¹,
Gao²,
Sun³
et al. 2017
J. vibroeng.
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This paper deals with the problem of getting dynamic characteristics in complex mechanical multi-body system. Based on the MFBD (Multi-Flexible-Body Dynamics) technology, the rigid-flexible coupling dynamic simulation method is proposed, and then the method is applied to the planetary gear transmission. The results show that the dynamic stress distribution of planetary gear can be obtained to determine the dangerous location, and the dynamic response characteristics are more obvious. Then the simulation model of planetary gear transmission with broken tooth is established, the fault feature extraction in time-frequency domain is carried out using the acceleration signal. In addition, industrial data is also used to validate the effectiveness of the proposed method.

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“…selection. Other iterative procedures have been proposed by Kim and Kang [11] and, more recently, by Lin et al [4] reaching an iterative solution that avoids inertia term truncation.…”

Section: Introductionmentioning
confidence: 99%

Dynamic reduction strategies to extend modal analysis approach at higher frequencies
Salvini
¹
,
Vivio
²

2007
Finite Elements in Analysis and Design
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Modal analysis on huge finite element models requires a numerical simplification in terms of total number of degrees of freedom (d.o.f.'s). The above aim is generally achieved by choosing some master d.o.f.'s and condensing the structure matrices on those d.o.f.'s. Static condensation (i.e. stiffness matrix reduction) is theoretically an errorless operation; on the other hand, mass condensation can only be approximate in dynamic applications. In order to accomplish matrix condensation, the technique mainly used is the so-called Guyan reduction. The present paper outlines the limitations of the technique, introducing some significant improvements. These are related to the inertia conservation properties of the reduced mass matrix and the condensed mass matrix assembly by means of fictitious and appropriate stiffness connections that are different from those obtained by the stiffness model. The effectiveness of the modified approach is demonstrated with respect to the modal analysis results obtained by Guyan approach, through three different test cases. ᭧

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Convergence acceleration of iterative modal reduction methods

Cited by 15 publications

References 0 publications

Hierarchical Strategies of Optimization for Structural System Identification Based on the Condensation Method

Hierarchical Strategies of Optimization for Structural System Identification Based on the Condensation Method

Rigid-flexible coupling dynamics simulation of planetary gear transmission based on MFBD

Dynamic reduction strategies to extend modal analysis approach at higher frequencies

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