scholarly journals Automotive dry clutch fully coupled transient tribodynamics

2021 ◽  
Author(s):  
I. Minas ◽  
N. Morris ◽  
S. Theodossiades ◽  
M. O’Mahony ◽  
J. Voveris
Keyword(s):  
Transient Dynamics ◽  
Dynamics Model ◽  
Input Shaft ◽  
Frictional Properties ◽  
Clutch System ◽  
Numerical Tool ◽  
Dry Clutch ◽  
Noise Vibration ◽  
The Stability ◽  
Fully Coupled

AbstractDetermining the root causes of Noise, Vibration and Harshness (NVH) phenomena in modern automotive drivetrains is a task of critical importance. This research investigates the stability of dry clutch systems vibrational behaviour during engagement. A fully coupled dry clutch numerical model including the influence of friction is presented and validated using vehicle measurements. The clutch component frictional properties are measured using parts that exhibit aggressive NVH behaviour using representative tribometric experiments. The validated numerical tool highlights the occurrence of instabilities which are caused by modal couplings, particularly between the input shaft bending and clutch disc radial motions. Such a validated transient dynamics model of a dry clutch system has not hitherto been presented in the open literature.

scholarly journals Noise, vibration and harshness during dry clutch engagement oscillations

2020 ◽  
Vol 234 (23) ◽  
pp. 4572-4588
Author(s):  
I Minas ◽  
N Morris ◽  
S Theodossiades ◽  
M O’Mahony
Keyword(s):  
Coefficient Of Friction ◽  
Numerical Models ◽  
Dynamic Coefficient ◽  
Driving Experience ◽  
Clutch Engagement ◽  
Pin On Disc ◽  
Dry Clutch ◽  
Interacting Surfaces ◽  
Noise Vibration ◽  
Dynamic Coefficient Of Friction

Determining the root causes of various noise, vibration and harshness phenomena in modern automotive drivetrains is a critical task for industry, since noise, vibration and harshness issues often result in worsened driving experience. The aim of the current research is to investigate the dynamics during dry clutch engagement and the associated – often problematic – oscillations. This paper reports the development and partial validation of numerical models to study dry clutch behaviour. The models are used to investigate the influence of clutch and throttle actuation on the occurrence of unwanted clutch oscillations. The dynamic coefficient of friction between the clutch interacting surfaces was measured using a pin-on-disc rig under different slip speeds and contact pressure conditions, which are representative of a typical clutch engagement manoeuvre. The paper highlights the occurrence of instability issues in clutch dynamics (disc radial mode) as potential generators of aggressive noise, vibration and harshness, particularly during two different clutch pedal actuations. Such analysis has not hitherto been reported in the open literature.

Numerical Investigation of the Influence of Friction Coefficient on Brake Groan

2010 ◽  
Vol 44-47 ◽  
pp. 1923-1927 ◽  
Author(s):  
Xian Jie Meng
Keyword(s):  
Nonlinear Dynamics ◽  
Friction Coefficient ◽  
Degrees Of Freedom ◽  
Equilibrium Points ◽  
Static Friction ◽  
Kinetic Friction ◽  
Dynamics Model ◽  
Excited Vibration ◽  
Nonlinear Dynamics Model ◽  
The Stability

A two degrees of freedom nonlinear dynamics model of self-excited vibration induced by dry-friction of brake disk and pads is built firstly, the stability of vibration system at the equilibrium points is analyzed using the nonlinear dynamics theory. Finally the numerical method is taken to study the impacts of friction coefficient on brake groan. The calculation result shows that with the increase of kinetic friction coefficient /or the decrease of difference value between static friction coefficient and kinetic friction coefficient can prevent or restrain self-excited vibration from happening.

scholarly journals Integrated Prognostics Observer for Condition Monitoring of an Automated Manual Transmission Dry Clutch System

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Sivakumar Ramalingam ◽  
Hanumath VV Prasad ◽  
Srinivasa Prakash Regalla
Keyword(s):  
Real Time ◽  
Condition Monitoring ◽  
Closed Loop ◽  
Manual Transmission ◽  
The Real ◽  
Clutch System ◽  
Loop Feedback ◽  
Automated Manual Transmission ◽  
Closed Loop Feedback ◽  
Dry Clutch

The closed loop feedback control system of an Automated Manual Transmission (AMT) electro-pneumatic clutch actuator is used for intelligent real time condition monitoring, enhanced diagnostics and prognostic health management of the dry clutch system, by integrating with the existing gearbox prognostics observer. The real-time sensor data of the clutch actuator piston position is analyzed for monitoring the condition of the clutch system. Original parameters of the new clutch are stored in the Electrically Erasable Programmable Read-only Memory (EEPROM) of the AMT controller and the real-time data is used by the observer for assessing the degradation/wear of the frictional clutch parts. Also, clutch slip during torque transmission is monitored, using the engine speed and the gearbox input shaft speed from Controller Area Network (CAN). Condition monitoring of clutch system provides enhanced prognostic functionality for AMT system which ensures consistent clutch performance, gear shift quality and timely warning for recalibration, repair and/or replacement of the critical wear and tear parts. Also, systematic analysis of the monitored data provides an accurate diagnosis of a developing fault. Thus, with the advanced control systems in place for AMT, a closed loop feedback based condition monitoring system is modelled for improved diagnostics and prognostics of AMT clutch system.

scholarly journals Observation of a Class of Disturbance in Time Series Expansion for Fractional Order Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Yiheng Wei ◽  
Hamid Reza Karimi ◽  
Jinwen Pan ◽  
Qing Gao ◽  
Yong Wang
Keyword(s):  
Time Series ◽  
Series Expansion ◽  
Fractional Order ◽  
Disturbance Observer ◽  
Higher Order ◽  
Transient Dynamics ◽  
Fractional Order Systems ◽  
Weighted Function ◽  
Numerical Examples ◽  
The Stability

This paper is concerned with the problem of designing disturbance observer for fractional order systems, of which the disturbance is in time series expansion. The stability of a special observer with the selected nonlinear weighted function and transient dynamics function is rigorously analyzed for slowly varying disturbance. In addition, the result is also extended to estimate slope forms disturbance and higher order disturbance of fractional order systems. The efficacy of the proposed method is validated through numerical examples.

Static Stability of Floating Units in Operational Conditions: A Physics-Driven Approach

2017 ◽  
Author(s):  
Neil Luxcey ◽  
Øystein Johannessen ◽  
Sébastien Fouques
Keyword(s):  
Static Stability ◽  
Stability Study ◽  
Operational Stability ◽  
Physical Models ◽  
Floating Platform ◽  
Line System ◽  
Operational Conditions ◽  
Axis Of Rotation ◽  
Numerical Tool ◽  
The Stability

When designing a new floating unit concept, static stability computations are performed in order to check stability criteria defined in regulations. Calculations for design conditions generally include the estimation of buoyancy force, gravity force and wind force acting on the floater for a given condition and a desired axis of rotation. However, when studying the stability of a floating platform in operational conditions, all external forces acting on the unit should be comprised in the assessment in order to get a more realistic — and even physically admissible — picture of the platform stability. Those forces include among others wind, current and anchor line system forces. In addition, limiting the study to one axis of rotation may not provide a complete picture of the floater stability, especially when the hull is of a semi-submersible type. Following this physical approach, a numerical tool has been developed based on the SINTEF Ocean’s SIMA software package. The latter package initially includes a time domain simulator of complex multibody systems for marine operations. The developed tool provides accurate physical models for each force component that may have effects on the stability. It opens the possibility to study the operational stability of a floater without restraining the study to one axis of rotation. It also allows the analysis of damaged conditions with large inclination angles. This paper describes the model implemented in this numerical tool. Validation work is presented for simple geometries. Results from an operational stability study of a semi-submersible are discussed. Finally, possible further work is discussed.

scholarly journals Tribodynamics of hydraulic actuated clutch system for engine-downsizing in heavy duty off-highway vehicles

2018 ◽  
Vol 233 (4) ◽  
pp. 976-993 ◽  
Author(s):  
Nader Dolatabadi ◽  
Ramin Rahmani ◽  
Stephanos Theodossiades ◽  
Homer Rahnejat ◽  
Guy Blundell ◽  
...  
Keyword(s):  
Heavy Duty ◽  
Multi Scale ◽  
Clutch System ◽  
Start Up ◽  
Clutch Engagement ◽  
Torque Capacity ◽  
Reduce Emissions ◽  
Dry Clutch ◽  
Physics Model ◽  
Multi Body

Engine downsizing is desired for modern heavy-duty vehicles to enhance fuel economy and reduce emissions. However, the smaller engines usually cannot overcome the parasitic loads during engine start-up. A new clutch system is designed to disconnect the downsized engine from the parasitic losses prior to the idling speed. A multi-scale, multi-physics model is developed to study the clutch system. Multi-body dynamics is used to study the combined translational–rotational motions of the clutch components. A micro-scale contact model is incorporated to represent the frictional characteristics of the sliding surfaces. Although the clutch is designed for dry contact operation, leakage of actuating hydraulic fluid can affect the interfacial frictional characteristics. These are integrated into the multi-body dynamic analysis through tribometric studies of partially wetted surfaces using fresh and shear-degraded lubricants. Multi-scale simulations include sensitivity analysis of key operating parameters, such as contact pressure. This multi-physics approach is not hitherto reported in the literature. The study shows the importance of adhesion in dry clutch engagement, enabling full torque capacity. The same is also noted for any leakage of significantly shear-degraded lubricant into the clutch interfaces. However, the ingression of fresh lubricant into the contact is found to reduce the clutch torque capacity.

NUMERICAL AND FINITE ELEMENT CONTACT TEMPERATURE ANALYSIS OF FRICTION MATERIAL ’S TYPE EFFECT ON A THERMAL TRANSIENT BEHAVIOR OF A SINGLE-DISC DRY CLUTCH

Tribologia ◽  
2018 ◽  
Vol 271 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Majid Habeb FAIDH-ALLAH
Keyword(s):  
Finite Element ◽  
Transient Behavior ◽  
Friction Material ◽  
Sliding Velocity ◽  
Friction Materials ◽  
Clutch System ◽  
Friction Clutch ◽  
Dry Clutch ◽  
Element Technique ◽  
Contact Temperature Analysis

The sliding period is considered a critical period in the lifetime of friction clutches, because most failures occur during this period. High temperatures due to sliding velocity will appear on the contacting surfaces of the friction clutch system (e.g., in single -disc clutch are pressure plate, clutch discs and flywheel). The finite element technique has been developed to investigate the effect of the type of friction material (material properties) on the transient thermoelastic behaviour of a single-disc dry clutch. Two types of friction materials are used in this work: organic and sintered friction materials. Axisymmetric models are developed to simulate a friction clutch system (single disc with two effective sides). The results represent the comparisons between organic and sintered friction discs, behaviours during slipping periods in clutches.

Instability of Shielded Surface Temperature Vortices

2011 ◽  
Vol 68 (5) ◽  
pp. 964-971 ◽  
Author(s):  
Benjamin J. Harvey ◽  
Maarten H. P. Ambaum ◽  
Xavier J. Carton
Keyword(s):  
Surface Temperature ◽  
Smooth Surface ◽  
Numerical Study ◽  
Normal Modes ◽  
Euler System ◽  
The Other ◽  
Two Dimensional ◽  
Dynamics Model ◽  
Contour Dynamics ◽  
The Stability

Abstract The stability characteristics of the surface quasigeostrophic shielded Rankine vortex are found using a linearized contour dynamics model. Both the normal modes and nonmodal evolution of the system are analyzed and the results are compared with two previous studies. One is a numerical study of the instability of smooth surface quasigeostrophic vortices with which qualitative similarities are found and the other is a corresponding study for the two-dimensional Euler system with which several notable differences are highlighted.

Adaptive Servo Control Based on LQR for Flexible Master-Slave System

2011 ◽  
Vol 130-134 ◽  
pp. 2433-2437
Author(s):  
Bai Long Jia ◽  
Ying Liu ◽  
Yukinori Kobayashi
Keyword(s):  
Vibration Suppression ◽  
Servo Control ◽  
Slave System ◽  
Dynamics Model ◽  
Servo Controller ◽  
The Stability ◽  
Short Time ◽  
Short Time Delay ◽  
Input Torque ◽  
Master Slave System

In this study, an adaptive servo controller based on LQR is designed for flexible master-slave system (FMSS). A dynamics model, observer and servo controller based on LQR is built respectively. According to the parameter sensitive experiments, adaptive servo controller based on LQR is designed. This research focuses on the performance of rapid response and vibration suppression. Experimental results indicate that adaptive servo controller, which suppresses the saturation of the input torque to ensure the stability, has achieved short time delay and adequate vibration suppression.

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