Vibration characteristic analysis of twenty-high rolling mill with local defect on roll surface based on the time-varying contact stiffness

2014 ◽  
Vol 42 ◽  
pp. 297-310 ◽  
Author(s):  
Shengli Wu ◽  
Liming Wang ◽  
Yimin Shao ◽  
Yilin Yuan
Keyword(s):  
Rolling Mill ◽  
Contact Stiffness ◽  
Local Defect ◽  
Time Varying ◽  
Vibration Characteristic ◽  
Roll Surface ◽  
Characteristic Analysis

scholarly journals Vibration Characteristic Analysis of Cracked Gear Based on Time-varying Meshing Stiffness

2020 ◽  
Vol 56 (17) ◽  
pp. 108
Author(s):  
MENG Zong ◽  
SHI Guixia ◽  
WANG Fulin ◽  
ZHAN Xuyang ◽  
FAN Fengjie
Keyword(s):  
Time Varying ◽  
Vibration Characteristic ◽  
Characteristic Analysis ◽  
Meshing Stiffness

Spatial Vibration Characteristics of Four-High Rolling Mills

2013 ◽  
Vol 694-697 ◽  
pp. 481-484
Author(s):  
Yong Jiang Zheng ◽  
Guang Xian Shen ◽  
Yi Geng Li ◽  
Ming Li ◽  
Hong Min Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rolling Mill ◽  
Vibration Modes ◽  
Vibration Characteristic ◽  
Characteristic Analysis ◽  
Rolling Mills ◽  
Spatial Vibration ◽  
Six Dof ◽  
Spatial Behaviors

The contemporary four-high mills are unstable and four-high rolling mill vibrations take place in six DOF leading to spatial behaviors involving vertical, horizontal, axial, reverse, cross and swinging vibration modes resulting in complex relative motions between the rolls. In this paper, a spatial vibration characteristic analysis of two four-high rolling mills with different stability will be presented based on the transfer matrix method (TMM) and Finite Element Method (FEM). The natural frequency and mode shape of four-high rolling mill are obtained. Vibration experimental results will be presented to prove the validity of the spatial vibration of rolling mill.

scholarly journals Vibration Characteristic Analysis and Simulation of High Speed Impact Penetrator

2018 ◽  
Vol 170 ◽  
pp. 022130
Author(s):  
Haitao Luo ◽  
Guangming Liu ◽  
Shipeng Chen ◽  
Wei Wang ◽  
Peng Wang
Keyword(s):  
High Speed ◽  
Vibration Characteristic ◽  
Characteristic Analysis ◽  
High Speed Impact

A New Model for the Relationship Between Vibration Characteristics Caused by the Time-Varying Contact Stiffness of a Deep Groove Ball Bearing and Defect Sizes

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Jing Liu ◽  
Yimin Shao ◽  
W. D. Zhu
Keyword(s):  
Surface Defect ◽  
Ball Bearing ◽  
Contact Stiffness ◽  
Vibration Characteristics ◽  
Time Varying ◽  
Defect Depth ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Length Width ◽  
The Relationship

Vibration characteristics of a deep groove ball bearing caused by a localized surface defect are greatly affected by defect sizes, such as the length, width, and depth. However, effects of the defect depth, the time-varying contact stiffness between the ball and defect, and the relationship between the time-varying contact stiffness and defect sizes have not been considered in previous defect models. In this work, a new defect model considering a new force–deflection relationship is presented to replace the Hertzian force–deflection relationship to describe the ball-line contact between the ball and defect edge. Both the time-varying displacement impulse and time-varying contact stiffness are considered. The relationship between the time-varying contact stiffness and defect sizes is obtained. Effects of defect sizes on the vibrations of the deep groove ball bearing, especially the defect depth that cannot be described by previous defect models, are investigated. The simulation results are compared with those from the previous defect models. The results show that the model developed can predict a more realistic impulse caused by a localized surface defect for dynamic simulation of the deep groove ball bearing. An experimental investigation is also presented to validate the proposed model.

Vibration Characteristic Analysis of V-Shaped Electrothermal Microactuator

2012 ◽  
Vol 503 ◽  
pp. 118-121
Author(s):  
Zhen Lu Wang ◽  
Xue Jin Shen ◽  
Ling Zhou ◽  
Xiao Yang Chen
Keyword(s):  
Theoretical Calculation ◽  
Natural Frequency ◽  
Mechanical Model ◽  
Natural Frequencies ◽  
Maximum Error ◽  
Vibration Characteristic ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
The Finite Element Analysis

This paper is focused on the finite element analysis (FEA) and theoretical calculation of vibration characterization of V-shaped electrothermal microactuator. A vibration mechanical model about V-shaped electrothermal microactuator is presented. By having a comparison between FEA and theoretical calculation about natural frequencies of V-shaped electrothermal microactuator, the maximum error is within 0.19 %. This paper also analyzes the influences of microactuator geometric parameters on natural frequency. The length and thickness have larger effect on the natural frequency of the actuator, while the angle and width have less effect on the natural frequency.

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.

Generic Friction Models for Time-Domain Vibration Analysis of Bladed Disks

2004 ◽  
Vol 126 (1) ◽  
pp. 184-192 ◽  
Author(s):  
E. P. Petrov ◽  
D. J. Ewins
Keyword(s):  
Time Domain ◽  
Normal Load ◽  
Contact Stiffness ◽  
Time Varying ◽  
Bladed Disks ◽  
Friction Forces ◽  
Friction Characteristics ◽  
Motion Trajectories ◽  
Friction Models ◽  
The Time Domain

New efficient models have been developed to describe dynamic friction effects in order to facilitate analysis of the vibration of bladed disks in the time domain. These friction models describe friction forces occurring at contact interfaces under time-varying normal load variations, including cases of separation. The friction models developed allow one to take into account time-varying friction contact parameters, such as friction coefficient and contact stiffness coefficients. Anisotropy and variation of the friction characteristics over the contact surfaces are included in the proposed models. The capabilities of the new friction models are demonstrated. Analysis of the friction forces is performed for different motion trajectories and different time variations of the normal load, and the effects of anisotropy, variation in time of the friction characteristics and normal load variation are discussed. A numerical analysis of transient vibrations of shrouded blades using the new models is presented.

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