Comparison of three Component Mode Synthesis methods for non-proportionally damped systems

2000 ◽  
Author(s):  
Jeffrey Morgan ◽  
Roy Craig, Jr.
Keyword(s):  
Component Mode Synthesis ◽  
Synthesis Methods ◽  
Damped Systems

A real decoupled method and free interface component mode synthesis methods for generally damped systems

2014 ◽  
Vol 333 (2) ◽  
pp. 584-603 ◽  
Author(s):  
Huan He ◽  
Tao Wang ◽  
Guoping Chen ◽  
Dongyang Sun ◽  
Rujie Sun
Keyword(s):  
Component Mode Synthesis ◽  
Synthesis Methods ◽  
Free Interface ◽  
Damped Systems ◽  
Decoupled Method

Nonbaseband residual flexibility method of component mode synthesis for proportionally damped systems

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 1285-1291
Author(s):  
Jeffrey A. Morgan ◽  
Christophe Pierre ◽  
Gregory M. Hulbert
Keyword(s):  
Component Mode Synthesis ◽  
Damped Systems

scholarly journals Component Mode Synthesis Using Undeformed Interface Coupling Modes to Connect Soft and Stiff Substructures

2013 ◽  
Vol 20 (1) ◽  
pp. 157-170 ◽  
Author(s):  
Eskil Lindberg ◽  
Nils-Erik Hörlin ◽  
Peter Göransson
Keyword(s):  
Degrees Of Freedom ◽  
Component Mode Synthesis ◽  
Vehicle Suspension ◽  
Synthesis Methods ◽  
Test Case ◽  
Rotation Axes ◽  
Acoustic Modelling ◽  
Stiffness Properties ◽  
Rubber Bushing ◽  
Vehicle Suspension System

Classical component mode synthesis methods for reduction are usually limited by the size and compatibility of the coupling interfaces. A component mode synthesis approach with constrained coupling interfaces is presented for vibro-acoustic modelling. The coupling interfaces are constrained to six displacement degrees of freedom. These degrees of freedom represent rigid interface translations and rotations respectively, retaining an undeformed interface shape. This formulation is proposed for structures with coupling between softer and stiffer substructures in which the displacement is chiefly governed by the stiffer substructure. Such may be the case for the rubber-bushing/linking arm assembly in a vehicle suspension system. The presented approach has the potential to significantly reduce the modelling size of such structures, compared with classical component mode synthesis which would be limited by the modelling size of the interfaces. The approach also eliminates problems of nonconforming meshes in the interfaces since only translation directions, rotation axes and the rotation point need to be common for the coupled substructures. Simulation results show that the approach can be used for modelling of systems that resemble a vehicle suspension. It is shown for a test case that adequate engineering accuracy can be achieved when the stiffness properties of the connecting parts are within the expected range of rubber connected to steel.

Rotating Mistuned Bladed Disk Assembly Dynamic Response Prediction Using Component Mode Synthesis Methods With Interface Modes

2005 ◽  
Author(s):  
Francois Duvauchelle ◽  
Duc-Minh Tran ◽  
Roger Ohayon
Keyword(s):  
Response Prediction ◽  
Forced Response ◽  
Component Mode Synthesis ◽  
Synthesis Methods ◽  
Cyclic Symmetry ◽  
Reduced Order ◽  
Bladed Disk ◽  
Static Condensation ◽  
Bladed Disk Assembly ◽  
Reduced Order Methods

Finite element-based reduced order methods are presented with application to the prediction of rotating mistuned bladed disk forced response. These methods have already been applied to tuned non-rotating models having cyclic symmetry. The aim is to reduce significantly the number of interface co-ordinates, which can be very important in classical component mode synthesis methods. The approach is based on the use of the interface modes which result from a static condensation of the whole structure on the whole interface. A first implementation of this procedure and numerical results are presented.

Component mode synthesis and stochastic perturbation method for dynamic analysis of large linear finite element with uncertain parameters

2020 ◽  
Vol 14 (2) ◽  
pp. 6753-6769
Author(s):  
D. Lamrhari ◽  
D. Sarsri ◽  
M. Rahmoune
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Perturbation Method ◽  
Transfer Functions ◽  
Second Order ◽  
Component Mode Synthesis ◽  
Order Perturbation ◽  
Physical Parameters ◽  
Synthesis Methods ◽  
Stochastic Perturbation Method

In this paper, a method to calculate the first two moments (mean and variance) of the stochastic time response as well as the frequency functions of large FE models with probabilistic uncertainties in the physical parameters is proposed. This method is based on coupling of second order perturbation method and component mode synthesis methods. Various component mode synthesis methods are used to optimally reduce the size of the model. The analysis of dynamic response of stochastic finite element system can be done in the frequency domain using the frequency transfer functions and in the time domain by a direct integration of the equations of motion, using numerical procedures. The statistical first two moments of dynamic response of the reduced system are obtained by the second order perturbation method. Numerical applications have been developed to highlight effectiveness of the method developed to analyze the stochastic response of large structures.

Probabilistic Mistuning Assessment Using Nominal and Geometry Based Mistuning Methods

2012 ◽  
Author(s):  
Joseph A. Beck ◽  
Jeffrey M. Brown ◽  
Charles J. Cross ◽  
Joseph C. Slater
Keyword(s):  
Prediction Error ◽  
Component Mode Synthesis ◽  
Mode Shapes ◽  
Synthesis Methods ◽  
Perturbation Approach ◽  
Engine Order ◽  
Simplifying Assumptions ◽  
Bladed Rotor ◽  
Design And Testing ◽  
Nominal Mode

Two deterministic mistuning models utilizing component mode synthesis methods are used in a Monte Carlo simulation to generate mistuned response distributions for a geometrically perturbed Integrally Bladed Rotor. The first method, a frequency-perturbation approach with a nominal mode approximation used widely in academia and industry, assumes airfoil geometric perturbations alter only the corresponding modal stiffnesses while its mode shapes remain unaffected. The mistuned response is then predicted by a summation of the nominal modes. The second method, a geometric method utilizing non-nominal modes, makes no simplifying assumptions of the dynamic response due to airfoil geometric perturbations, but requires recalculation of each airfoil eigen-problem. A comparison of the statistical moments of the mistuned response distributions and prediction error is given for three different frequency ranges and engine order excitations. Further, the response distributions are used for a variety of design and testing scenarios to highlight impacts of the frequency-based approach inaccuracy. Results indicate the frequency-based method typically provides conservative response levels.

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