scholarly journals Multi Scale Modelling of Friction Induced Vibrations at the Example of a Disc Brake System

2021 ◽  
Vol 2 (4) ◽  
pp. 1037-1056
Author(s):  
Arn Joerger ◽  
Ioannis Spiropoulos ◽  
Robert Dannecker ◽  
Albert Albers
Keyword(s):  
Finite Element ◽  
Automobile Industry ◽  
Element Model ◽  
Brake System ◽  
Disc Brake ◽  
Micro Scale ◽  
Macro Scale ◽  
Scale Modelling ◽  
The Coefficient Of Friction ◽  
Multi Body

Friction induced vibrations such as brake squealing, or juddering are still challenging topics in product engineering processes. So far, this topic was particularly relevant for the automobile industry because they were the main market for disc brake systems. However, since mobility habits change, disc brake system are more often to be found on bikes or e-scooters. In all of these systems, vibrations are excited in contacts on the micro scale but affect the user comfort and safety on the macro scale. Therefore, the aim of this cross-scale method is to analyze a system on a micro scale and to transfer the excitation mechanisms on a macro scale system. To address both scales, the current work presents a finite element model on the micro scale for the determination of the coefficient of friction, which is transferred to the macro scale and used in a multi-body simulation. Finally, a finite element modal analysis is conducted, which allowed us to evaluate the brake system behavior on base of an excitation.

Contact characteristic analysis of spindle–toolholder joint at high speeds based on the fractal model

2016 ◽  
Vol 231 (5) ◽  
pp. 1025-1036 ◽  
Author(s):  
Yongsheng Zhao ◽  
Jingjing Xu ◽  
Ligang Cai ◽  
Weimin Shi ◽  
Zhifeng Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Hybrid Model ◽  
Contact Stiffness ◽  
Element Model ◽  
Fractal Model ◽  
Contact Ratio ◽  
Characteristic Analysis ◽  
Micro Scale ◽  
High Speeds ◽  
Macro Scale

Due to the influence of centrifugal force, accurate contact stiffness model of spindle–toolholder joint at high speeds is crucial in predicting the dynamic behavior and chatter vibration of spindle–toolholder system. In this paper, a macro–micro scale hybrid model is presented to obtain the contact stiffness of spindle–toolholder joint in high speeds. The hybrid model refers to the finite element model in macro-scale and three-dimensional fractal model in micro-scale. The taper contact surface of spindle–toolholder joint is assumed flat in macro-scale and the finite element method is used to obtain the pressure distribution at different speeds. In micro-scale, the topography of contact surfaces is fractal featured and determined by fractal parameters. Asperities in micro-scale are considered as elastic and plastic deformation. Then, the contact ratio, radial and torsional contact stiffness of spindle–toolholder joint can be calculated by integrating the micro asperities. Experiments with BT40 type toolholder–spindle assembly are conducted to verify the proposed model in the case of no speed. The reasonable intervals of spindle speed and drawbar force can be obtained based on the presented hybrid model, which will provide theoretical basis for the application and optimization of the spindle–toolholder system.

Dynamic Characteristic Analysis of Irregularity under Turnout by Vehicle-Turnout Rigid-Flexible Coupling Model

2014 ◽  
Vol 945-949 ◽  
pp. 591-595 ◽  
Author(s):  
Meng Chen ◽  
Yan Yun Luo ◽  
Bin Zhang
Keyword(s):  
Finite Element ◽  
Longitudinal Direction ◽  
Element Model ◽  
Vertical Displacement ◽  
Coupling Model ◽  
Interaction Force ◽  
Vertical Acceleration ◽  
Characteristic Analysis ◽  
Flexible Coupling ◽  
Multi Body

Finite element model of track in frog zone is built by vehicle-turnout system dynamics. Considering variation of rail section and elastic support, bending deformation of turnout sleeper, spacer block and sharing pad effects, the track integral rigidity distribution in longitudinal direction is calculated in the model. Vehicle-turnout rigid-flexible coupling model is built by finite element method (FEM), multi-body system (MBS) dynamics and Hertz contact theory. With the regularity solution that different stiffness is applied for rubber pad under sharing pad of different turnout sleeper zone, analysis the variation of vertical acceleration of bogie and wheelset, rail vertical displacement and wheel-rail interaction force, this paper proves that setting reasonable rubber pad stiffness is an efficient method to solve rigidity irregularity problem.

Squeal Analysis of a Disc Brake Considering Damping between a Disc and a Pad Lining

2012 ◽  
Vol 157-158 ◽  
pp. 1000-1003
Author(s):  
Ke Wei Zhou ◽  
Cheol Kim ◽  
Min Ok Yun ◽  
Ju Young Kim
Keyword(s):  
Finite Element ◽  
Equations Of Motion ◽  
Element Model ◽  
Disc Brake ◽  
Vibration Modes ◽  
Assumed Mode Method ◽  
Frictional Damping ◽  
System Components ◽  
Mode Method ◽  
Assumed Mode

The improved equations of motion for a friction-engaged brake system have been newly derived on the basis of the assumed mode method and frictional damping. The equations of motion with a finite element model were constructed by a set of vibration modes found from FE modal analysis on all system components. Consequently, the modal information of system components are combined with equations of motion derived from the analytical model. Numerical analysis showed the mode which was unstable in an undamped case became stable in a damped case.

scholarly journals Squeal Frequency of a Railway Disc Brake Evaluation by FE Analyses

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
F. Cascetta ◽  
F. Caputo ◽  
A. De Luca
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Experimental Tests ◽  
Numerical Approach ◽  
System Stability ◽  
Brake System ◽  
Physical Parameters ◽  
Disc Brake ◽  
Complex Eigenvalues ◽  
The Stability

This paper deals with the development of a numerical model, based on the Finite Element (FE) theory for the prediction of the squeal frequency of a railway disc brake. The analytical background has been discussed and presented, as well as the most efficient methods for evaluating the system stability; the attention has been paid particularly to the complex eigenvalues method, which has been adopted within this paper to investigate the railway disc brake system. Numerical results have been compared with measurements from experimental tests in order to validate the proposed numerical approach. At the end of this work, a sensitivity analysis, aimed at understanding the effects of some physical parameters influencing the stability of the brake system and the squeal propensity, has been carried out.

Numerical investigation of friction joint between Basalt Fiber Reinforced Composites and aluminum

2016 ◽  
Vol 231 (5) ◽  
pp. 543-551
Author(s):  
Andrei Costache ◽  
Christian Berggreen ◽  
Ion Marius Sivebæk ◽  
Kristian Glejbøl
Keyword(s):  
Finite Element ◽  
Basalt Fiber ◽  
Element Model ◽  
Fiber Reinforced ◽  
Pullout Force ◽  
Flexible Pipes ◽  
The Coefficient Of Friction ◽  
Flexible Risers ◽  
Offshore Oil Industry ◽  
Unbonded Flexible Pipes

Flexible risers are used in the offshore oil industry for exporting hydrocarbons from subsea equipment to floating production and storage vessels. The latest research in unbonded flexible pipes aims to reduce weight by replacing metal components with composite materials. This would result in lighter and stiffer flexible risers, which would be well suited for ultra deep water applications. This paper develops a new finite element model used for evaluating the efficiency of anchoring flat unidirectional fiber reinforced tendons in a mechanical grip. It consists two flat grips with the fiber reinforced tendon in between. The grips are pressed against the composite and the pullout force is ensured through friction. The novelty of the paper is represented by the detailed investigation of the influence between the coefficient of friction and the pullout force. By comparing numerical and experimentally obtained results, it is possible to show the importance of friction decay in the grip. Improper contact between the grips and composite is also taken into account and leads to good agreement between numerical and experimental results. This study shows how to avoid over-estimating the efficiency of such grip by using dry friction in finite element models.

Finite Element Modeling and Analysis of Rolling Bearing Based on Explicit Dynamics

2013 ◽  
Vol 397-400 ◽  
pp. 589-592 ◽  
Author(s):  
Jing Cui ◽  
Hua Qing Wang ◽  
Fei Xiao ◽  
Zuo Yi Dong
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Rolling Bearing ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Body Contact ◽  
Explicit Dynamics ◽  
Deep Groove ◽  
Rolling Elements ◽  
Multi Body

A finite element model of a rolling bearing with ANSYS/LS-DYNA is bulit , considering pressure, speed, multi-body contact effects and constraints under friction. The movement process of the rolling bearing based on explicit dynamics is simulated successfully. Several relevant parameters of 6205 deep groove ball bearing are calculated and determined. The results show that rotational speeds of cage and rolling elements which get from finite element analysis are consistent with the theoretical calculated values and stress situations are the same as Hertz analysis solutions. It proves that the proposed model is effective, which lays a foundation for subsequent analysis and diagnosis for defected bearings.

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