Modal Analysis of Automotive Clutch Using Finite Element Method

2014 ◽  
Author(s):  
Yasser Aktir ◽  
Jean-François Brunel ◽  
Philippe Dufrenoy ◽  
Hervé Mahe
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Natural Vibrations ◽  
Input Shaft ◽  
Vibration Properties ◽  
Clutch System ◽  
Automotive Clutch

Clutch system is an important element in the vehicle powertrain. It transmits the rotation from the crankshaft to the gearbox input shaft and filters axial and torsional vibrations providing from engine or induced by friction. This paper discusses axial dynamic behavior of automotive clutch for manual transmission. For this study, a tridimensional finite element model of clutch system is developed to simulate a clutch shaker test. First, an impact hammer test is performed to identify vibration properties of each clutch component. A pre-stressed modal analysis is then carried out to determine mode shapes and its associated natural frequencies of the clutch assembly. Shaker and simulation results are eventually compared to validate the clutch model. This latter offers for the design phase, a tool to avoid natural vibrations or to vibrate at specified frequencies.

Natural Vibrations of a Clamped-Clamped Arch With an Open Transverse Crack

1997 ◽  
Vol 119 (2) ◽  
pp. 145-151 ◽  
Author(s):  
M. Krawczuk ◽  
W. Ostachowicz
Keyword(s):  
Finite Element ◽  
Stiffness Matrix ◽  
Edge Crack ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Curved Beam ◽  
Natural Vibrations ◽  
Crack Location ◽  
Cracked Arch

The paper presents a finite element model of the arch with a transverse, one-edge crack. A part of the cracked arch is modelled by a curved beam finite element with the crack. Parts of the arch without the crack are modelled by noncracked curved beam finite elements. The crack occurring in the arch is nonpropagating and open. It is assumed that the crack changes only the stiffness of the arch, whereas the mass is unchanged. The method of the formation of the stiffness matrix of a curved beam finite element with the crack is presented. The effects of the crack location and its length on the changes of the in-plane natural frequencies and mode shapes of the clamped-clamped arch are studied.

Follower Effect of Internal Pressure on Modal Analysis of a Space Inflatable Structure

2015 ◽  
Vol 727-728 ◽  
pp. 578-582
Author(s):  
Fei Liu ◽  
Wei Liang He
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Fem Model ◽  
Configuration Change ◽  
Modal Behavior ◽  
Good Agreement ◽  
Inflatable Structure

The stress distribution and modal behavior of a space inflatable torus was investigated by nonlinear finite element numerical method. This paper focused on the effect of follower pressure on the modal analysis of the torus, including the effect of configuration change and follower pressure stiffness, and focused on validating the follower pressure stiffness FEM model and its applicability to modal analysis. Research shows that the changed configuration slightly increases the natural frequencies. The follower pressure stiffness significantly reduces the natural frequencies and changes mode shapes order. The modal results are in good agreement with the corresponding shell theory solutions, indicating that the finite element model of the follower pressure stiffness for the inflatable structure modal analysis in this paper is accurate enough and reasonable.

scholarly journals Dynamics Characteristics of Blast Furnace Shell

2011 ◽  
Vol 2-3 ◽  
pp. 1018-1020
Author(s):  
De Chen Zhang ◽  
Yan Ping Sun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Blast Furnace ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Theoretical Foundation ◽  
Structural Mechanics ◽  
Mode Shapes ◽  
The Future ◽  
Element Method

Finite element method and structural mechanics method are used to study the blast furnace shell modal analysis and the natural frequencies and mode shapes have been calculated. The two methods were compared and validated , and the results provide a theoretical foundation for the anti-vibration capabilities design of blast furnace shell in the future .

Coupled Bending-Torsion Vibration of Geared Rotors

1995 ◽  
Author(s):  
J. S. Rao ◽  
J. R. Chang ◽  
T. N. Shiau
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Mesh Stiffness ◽  
Present Program ◽  
Gear Mesh ◽  
Pressure Angle ◽  
Torsion Vibration ◽  
Gear Mesh Stiffness

Abstract A general finite element model is presented for determining the coupled bending-torsion natural frequencies and mode shapes of geared rotors. Uncoupled bending and torsion frequencies are obtained for examples available in literature and the present program is verified against these. The effect of the gear box is considered to determine the coupled frequencies. Parameters studied include the pressure angle, gear mesh stiffness, and bearing properties. The gear pressure angle is shown to have no effect on the natural frequencies of rotors supported on isotropic bearing supports. Several case studies with bending-torsion coupling are considered and the results obtained are compared with those available in literature. The results of a general rotor system with 8lodes are also presented.

Comparing Measured Responses of an Offshore Structure with Operational Modal Analysis assisted Classical Model Approach

2020 ◽  
pp. 1-10
Author(s):  
Bruna Nabuco ◽  
Sandro D. Amador ◽  
Evangelos I. Katsanos ◽  
Ulf T. Tygesen ◽  
Erik Damgaard Christensen ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Element Model ◽  
Operating Conditions ◽  
Operational Modal Analysis ◽  
Mode Shapes ◽  
Wave Forces ◽  
Wave Load ◽  
Offshore Structure

Abstract Aiming to ensure the structural integrity of an offshore structure, wave-induced responses have been measured during normal operating conditions. Operational Modal Analysis is applied to the data obtained from continuously monitoring the structure. Sensors placed only on the topside of an offshore platform are sufficient to provide information to identify the modal properties of the structure, such as natural frequencies, damping ratios, and mode shapes. A finite element model is created and updated in line with the identified dynamic properties for applying a modal expansion technique in the interest of accessing information at any point of the structure. Wave radars are also placed at the platform from which the wave forces are calculated based on basic industrial standard models. In this way, the wave kinematics are estimated according to the linear wave theory associated with Wheeler stretching. Since this study is related to offshore structures composed by slender elements, the wave forces are estimated using Morison formulation. By assigning typical values to the drag and inertia coefficients, wave loads are estimated and applied to the updated finite element model. For the diffraction effect, the wave load has also been evaluated according to MacCamy and Fuchs theory. The responses obtained from this procedure are compared with measured responses. In addition to describing the process, this paper presents a case study to verify the theory using monitoring data from a tripod jacket. Results indicate realistic response estimation that contributes to the knowledge about the state of the structure.

Support-Condition Analyses of Rotating Beams Under Distributed Imbalance Loading

2011 ◽  
Author(s):  
Kai Jokinen ◽  
Erno Keskinen ◽  
Marko Jorkama ◽  
Wolfgang Seemann
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cross Section ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Constant Cross Section ◽  
Support Condition ◽  
Beam Elements

In roll balancing the behaviour of the roll can be studied either experimentally with trial weights or, if the roll dimensions are known, analytically by forming a model of the roll to solve response to imbalance. Essential focus in roll balancing is to find the correct amount and placing for the balancing mass or masses. If this selection is done analytically the roll model used in calculations has significant effect to the balancing result. In this paper three different analytic methods are compared. In first method the mode shapes of the roll are defined piece wisely. The roll is divided in to five parts having different cross sections, two shafts, two roll ends and a shell tube of the roll. Two boundary conditions are found for both supports of the roll and four combining equations are written to the interfaces of different roll parts. Totally 20 equations are established to solve the natural frequencies and to form the mode shapes of the non-uniform roll. In second model the flexibility of shafts and the stiffness of the roll ends are added to the support stiffness as serial springs and the roll is modelled as a one flexibly supported beam having constant cross section. Finally the responses to imbalance of previous models are compared to finite element model using beam elements. Benefits and limitations of each three model are then discussed.

Hydroelastic Modal Analysis of the Perforated Cylindrical Shell in SMART

2011 ◽  
Author(s):  
Youngin Choi ◽  
Seungho Lim ◽  
Kyoung-Su Park ◽  
No-Cheol Park ◽  
Young-Pil Park ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Steam Generators ◽  
Structure Interaction ◽  
The Finite Element Model ◽  
Reactor Internals

The System-integrated Modular Advanced ReacTor (SMART) developed by KAERI includes components like a core, steam generators, coolant pumps, and a pressurizer inside the reactor vessel. Though the integrated structure improves the safety of the reactor, it can be excited by an earthquake and pump pulsations. It is important to identify dynamic characteristics of the reactor internals considering fluid-structure interaction caused by inner coolant for preventing damage from the excitations. Thus, the finite element model is constructed to identify dynamic characteristics and natural frequencies and mode shapes are extracted from this finite element model.

Modal Analysis of Flexible Assembling Fixture for Aircraft Panel Component

2010 ◽  
Vol 97-101 ◽  
pp. 3392-3396
Author(s):  
Li Gang Qu ◽  
Ke Qiang Pan ◽  
Xin Chen
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Characteristic ◽  
Natural Frequencies ◽  
Great Influence ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Dynamic Vibration ◽  
Structural Weakness ◽  
Modal Vibration

The dynamic characteristic of flexible assembling fixture (FAF) for aircraft panel component is analysed by the method of finite element modal analysis. Consequently, the every order of natural frequencies and mode shapes of given different postures of the FAF are obtained. It structural weakness were pointed out through the analysis results of the modal vibration characteristics. The properties of mass and stiffness of the FAF's components are concurrently calculated, whose optimal matching and harmonizing with each other have great influence on the dynamic vibration characteristics of the FAF. As the results of these analysis, the design improving suggestion for the FAF is put forward.

Positioning of bearings for curved continuous spread-box girder bridges

2002 ◽  
Vol 29 (5) ◽  
pp. 641-652 ◽  
Author(s):  
Magdy Samaan ◽  
Khaled Sennah ◽  
John B Kennedy
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Structural Response ◽  
Element Model ◽  
Extensive Study ◽  
Mode Shapes ◽  
Box Girder ◽  
Girder Bridges ◽  
Bridge Superstructure ◽  
Girder Bridge

The type and arrangement of bearings for a bridge superstructure are important considerations in bridge design. For a curved continuous spread-box girder bridge, the support conditions for the bridge superstructure may significantly influence the distribution factors for maximum stresses, reactions, and shear forces as well as the bridge natural frequencies and mode shapes. Current design practices in North America recommend very few guidelines for bearing arrangements and types. This paper describes an extensive study carried out using an experimentally calibrated finite element model, in which curved continuous prototype bridges were analyzed to determine their structural response. Six different types and arrangements of support bearings were studied to determine their effect on the maximum stress and reaction distributions as well as on the natural frequencies of such bridges. The results were used to suggest the most favourable bearing arrangement and type.Key words: bridge bearings, composite, continuous, curved bridges, design, distribution factors, finite element, spread-box.

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