Analysis on Torsional Vibration of Low-Speed Diesel

2012 ◽  
Vol 562-564 ◽  
pp. 528-531
Author(s):  
Zhong Ming Liu ◽  
Kai Liu ◽  
Xiao Qin Hou
Keyword(s):  
Shear Stress ◽  
Torsional Vibration ◽  
Critical Speed ◽  
Angular Displacement ◽  
Good Condition ◽  
Lumped Mass ◽  
Main Bearing ◽  
Bolt Preload ◽  
Lumped Mass Method ◽  
Vibration Model

In order to analysis the torsional vibration of crankshaft train in various assembly conditions, a 5S60 diesel model is presented based on AVL-EXCITE. A torsional vibration model is established by using the lumped mass method. And the deformation of main bearing is calculated under the bolt preload and outbreak of combustion. In addition to rated conditions, a state of one cylinder out of service is considered in this project. According to the calculation of the critical speed, torsion modes, angular displacement, shear stress in crankpin and minimum oil film thickness, the torsional vibration characteristics are analyzed. The study revealed that this system performs in good condition and the resonance is not obvious.

scholarly journals Modeling and Analysis of Amplitude-Frequency Characteristics of Torsional Vibration for Automotive Powertrain

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Jinli Xu ◽  
Jiwei Zhu ◽  
Feifan Xia
Keyword(s):  
Torsional Vibration ◽  
Transmission Error ◽  
Frequency Characteristics ◽  
Response Analysis ◽  
Lumped Mass ◽  
Modeling And Analysis ◽  
Gear Mesh ◽  
Runge Kutta Method ◽  
Lumped Mass Method ◽  
Automotive Powertrain

In the present paper, the amplitude-frequency characteristics of torsional vibration are discussed theoretically and experimentally for automotive powertrain. A bending-torsional-lateral-rocking coupled dynamic model with time-dependent mesh stiffness, backlash, transmission error etc. is proposed by the lumped-mass method to analysis the amplitude-frequency characteristic of torsional vibration for practical purposes, and equations of motive are derived. The Runge–Kutta method is employed to conduct a sweep frequency response analysis numerically. Furthermore, a torsional experiment is performed and validates the feasibility of the theoretical model. As a result, some torsional characteristics of automotive powertrain are obtained. The first three-order nature torsional frequencies are predicted. Torsional behaviors only affect the vibration characteristics of a complete vehicle at low-speed condition and will be reinforced expectedly while increasing torque fluctuation. Gear mesh excitations have little effects on torsional responses for such components located before mesh point but a lot for ones behind it. In particular, it is noted that the torsional system has a stiffness-softening characteristic with respect to torque fluctuation.

scholarly journals Investigation of the effect of the angle between drive shafts on vibration responses of main reducer

2018 ◽  
Vol 189 ◽  
pp. 06009 ◽  
Author(s):  
Xiaogang Liu ◽  
Zhaoyu Wu ◽  
Weiguang Shu ◽  
Jie Lu
Keyword(s):  
Hypoid Gear ◽  
Force Analysis ◽  
Lumped Mass ◽  
Mesh Stiffness ◽  
Gear Backlash ◽  
Lumped Mass Method ◽  
Vibration Model ◽  
Vibration Responses ◽  
Transfer Error ◽  
Final Drive

The drive shaft arrangement has a considerable influence on the vibration responses of the shaft-final drive system. In this research, a coupled vibration model is developed based on force analysis of hypoid gear and lumped mass method. The effect of time-varying mesh stiffness, gear backlash and transfer error are included to investigate the effect of the angle between drive shafts on vibration responses of main reducer. The vibration responses of main reducer are acquired using this model. The results show that the vibration amplitude of the gears of main reducer increase with the angle between drive shafts. This paper presents an analytical method to determine the value of the angle between drive shafts, so as to control the vibration of main reducer.

One-Dimensional Bi-Stage Phononic Band Gap Shaft Structure for Reducing Torsional Vibration

2011 ◽  
Vol 141 ◽  
pp. 54-58 ◽  
Author(s):  
Li Xia Li ◽  
Tian Ning Chen ◽  
Xiao Peng Wang ◽  
Bo Li
Keyword(s):  
Band Gap ◽  
Torsional Vibration ◽  
Band Gaps ◽  
Relative Width ◽  
Vibration Band ◽  
Lumped Mass ◽  
One Dimensional ◽  
Phononic Band Gap ◽  
Lumped Mass Method ◽  
The One

In this paper, a one-dimensional bi-stage phononic band gap (PBG) structure based on double local resonant effects is presented to reduce the torsional vibration for the first time. A unit cell of the bi-stage PBG structure is composed of two harmonic LR oscillators in the radial direction, distributed periodically along the shaft. A new method, combining the transfer matrix method and the lumped-mass method is proposed to study the torsional vibration band gaps of the double PBG-like shaft theoretically and proved by the finite element method. The results show that the mid-gap frequency of the bi-stage PBG structure shaft is lower than that in the one-stage PBG shaft and the relative width of the band gaps reaches 1.3 with the average attenuation of the vibration amplitude about 40dB.

Dynamic Analysis and Research of Motor’s Elastic Shaft of the Large Miner High Shearer’s Cutting Parts

2011 ◽  
Vol 108 ◽  
pp. 105-110 ◽  
Author(s):  
Hong Bing Gao ◽  
Zhao Jian Yang
Keyword(s):  
Dynamic Analysis ◽  
Theoretical Basis ◽  
Critical Speed ◽  
Lagrange Equation ◽  
Angular Displacement ◽  
Analysis Model ◽  
Lumped Mass ◽  
Shaft System ◽  
Elastic Shaft ◽  
Set Up

Take one large miner high electric draught shearer for example. According to the lumped mass method, the gear’s moment of inertia of the shearer’s cutting part was equivalent to the gears connecting the output shaft of the electric cutting motor, the stiffness of central shaft and coupling was equivalent to the output elastic shaft of the electric cutting motor, and the dynamic analysis model of the elastic shaft of the cutting part was set up. Based on this model, the lagrange equation was built. The critical speed of the elastic shaft system, the motion situation on main vibration and harmonic vibration mode, motor shaft’s angular displacement, angular velocity, and angular acceleration’s dynamic response process under the condition of step loads were all analyzed and obtained. The critical speed provided theoretical basis for choosing the working speed of every shaft system of the shearer. The hollow elastic shaft had a protective effect to cutting motor’s damping and overload. The research results provided theoretical basis for the design of the elastic shaft of large miner high shearer.

Modeling and Solution of a Nonlinear Vibration Model of the Bending-Torsion Coupled Spur Gear Transmission System Based on Lumped Mass Method

2014 ◽  
Vol 635-637 ◽  
pp. 172-176
Author(s):  
Chang Li ◽  
Bing Chen Wang ◽  
Xing Han
Keyword(s):  
Nonlinear Vibration ◽  
Optimization Design ◽  
Spur Gear ◽  
Lumped Mass ◽  
Lumped Mass Method ◽  
Vibration Model ◽  
Gear Transmission System ◽  
Tooth Surfaces ◽  
The Time Domain ◽  
Fifth Order

After comprehensive considerations of the influences of stiffness excitations, deviation excitations, meshing impact excitations, friction of tooth surfaces, gap changes and other kinds of nonlinear factors, it established a nonlinear vibration model of the bending-torsion coupled spur gear driven system based on Lumped Mass Method (LMM). By transforming the model to dimensionless form and using fifth order adaptive variable step (Runge-Kutta) method to solve the nonlinear vibration model of the system, it can get the time domain charts, spectrum charts, phase charts, Poincare charts, FFT charts and the system bifurcation figures. And then it discussed the influence of system parameter vibrations on its dynamic characteristics, and this could provide a foundation for system dynamic optimization design

A Simplified Model of SSI Dynamic Analysis

2012 ◽  
Vol 446-449 ◽  
pp. 334-339
Author(s):  
Zhi Ying Zhang ◽  
Ying Li ◽  
Qing Sun
Keyword(s):  
Dynamic Analysis ◽  
Soil Structure ◽  
Design Method ◽  
Simplified Model ◽  
Lumped Mass ◽  
Foundation Soil ◽  
Linear Elastic ◽  
Lumped Mass Method ◽  
Actual Mechanism ◽  
Seismic Design Method

Aiming at the problem of dynamic analysis of SSI system, the dynamic influence of different parts of foundation soil is studied on the linear elastic assumption according to the actual mechanism of Soil-Structure Interaction (SSI); in addition, a simplified model on the condition of the lumped mass method is put forward and the corresponding motion equations of SSI system are built, which can be a reference for the structural seismic design method considering SSI effect.

Dynamic Modeling of the Torsional Vibration of the Slewing Mechanism of a Hydraulic Excavator

2012 ◽  
Vol 253-255 ◽  
pp. 2102-2106 ◽  
Author(s):  
Xu Juan Yang ◽  
Zong Hua Wu ◽  
Zhao Jun Li ◽  
Gan Wei Cai
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Moment Of Inertia ◽  
Hydraulic Excavator ◽  
Planetary Gear Trains ◽  
Vibration Model ◽  
Gear Trains ◽  
The Moment ◽  
Relationship Of

A torsional vibration model of the slewing mechanism of a hydraulic excavator is developed to predict its free vibration characteristics with consideration of many fundamental factors, such as the mesh stiffness of gear pairs, the coupling relationship of a two stage planetary gear trains and the variety of moment of inertia of the input end caused by the motion of work equipment. The natural frequencies are solved using the corresponding eigenvalue problem. Taking the moment of inertia of the input end for example to illustrate the relationship between the natural frequencies of the slewing mechanism and its parameters, based on the simulation results, just the first order frequency varies significantly with the moment of inertia of the input end of the slewing mechanism.

Modeling and Simulation of Clamp Band Dynamic Envelope in a LV/SC Separation System

2011 ◽  
Vol 141 ◽  
pp. 359-363 ◽  
Author(s):  
Jun Lan Li ◽  
Shao Ze Yan ◽  
Xue Feng Tan
Keyword(s):  
Friction Coefficient ◽  
Modeling And Simulation ◽  
Band System ◽  
Separation Process ◽  
Impact Behavior ◽  
Separation System ◽  
Lumped Mass ◽  
Lumped Mass Method ◽  
Simulation Results ◽  
Contact Impact

The clamp band system is a typical locked and separated device of the launch vehicle (LV) / the spacecraft (SC), and its release-separation process is one of the important factors that affect the LV/SC separation movement. A nonlinear spring-damper model was employed to describe the contact-impact behavior between the V-segment of the clamp band and the LV/SC interface, and lumped mass method was used to depict the clamp band. By using ADAMS, a dynamic model of the clamp band system was established. The simulation results show that the impulse of the explosive bolts and the stiffness of lateral-restraining springs have significant effects on the clamp band dynamic envelope. The shock of the satellite-vehicle separation is very vulnerable to the clamp band pretension and the friction coefficient between the V-segment and the LV/SC interface.

Coupled Torsional Vibration and Fatigue Damage of Turbine Generator Due to Grid Disturbance

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Chao Liu ◽  
Dongxiang Jiang ◽  
Jingming Chen
Keyword(s):  
Fatigue Damage ◽  
Torsional Vibration ◽  
Coupled System ◽  
Lumped Mass ◽  
Mass Model ◽  
Turbine Generator ◽  
Failure Prevention ◽  
Lumped Mass Model ◽  
Continuous Mass ◽  
Fatigue Evaluation

Crack failures continually occur in shafts of turbine generator, where grid disturbance is an important cause. To estimate influences of grid disturbance, coupled torsional vibration and fatigue damage of turbine generator shafts are analyzed in this work, with a case study in a 600MW steam unit in China. The analysis is the following: (i) coupled system is established with generator model and finite element method (FEM)-based shafts model, where the grid disturbance is signified by fluctuation of generator outputs and the shafts model is formed with lumped mass model (LMM) and continuous mass model (CMM), respectively; (ii) fatigue damage is evaluated in the weak location of the shafts through local torque response computation, stress calculation, and fatigue accumulation; and (iii) failure-prevention approach is formed by solving the inverse problem in fatigue evaluation. The results indicate that the proposed scheme with continuous mass model can acquire more detailed and accurate local responses throughout the shafts compared with the scheme without coupled effects or the scheme using lumped mass model. Using the coupled torsional vibration scheme, fatigue damage caused by grid disturbance is evaluated and failure prevention rule is formed.

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