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.

Seismic Response Analysis on Pile-Soil Couple System by Lumped Mass Method

2011 ◽  
Vol 94-96 ◽  
pp. 1420-1423
Author(s):  
Li Qiang Wang ◽  
Yuan Zhan Wang
Keyword(s):  
Differential Equation ◽  
Seismic Response ◽  
Soil Structure ◽  
Couple System ◽  
Response Analysis ◽  
Lumped Mass ◽  
Deep Foundation ◽  
Lumped Mass Method ◽  
Model Pile ◽  
Mechanical Characters

Pile is widely used as deep foundation in civil engineering. The dynamic interaction between pile and soil is an important problem in the field of soil-structure interaction. This paper established a model to calculate the seismic response of pile-soil couple system. In this model, pile and soil are regarded as lumped mass, soil was divided into two parts: the far region soil and near pile region soil. These two parts are simulated by different mechanical characters. A differential equation of motion of pile-soil couple system was established in the paper, this differential equation can be solved by Wilson-θ method. An example was introduced to study the behavior of pile-soil couple system.

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.

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 dynamic analysis of spiral bevel gear coupled system of intermediate and tail gearboxes in a helicopter

2021 ◽  
pp. 095440622199279
Author(s):  
Haimin Zhu ◽  
Weifang Chen ◽  
Rupeng Zhu ◽  
Li Zhang ◽  
Bibo Fu ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Torsional Vibration ◽  
Transmission Error ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Lateral Vibration ◽  
Lumped Mass ◽  
Coupled Effect ◽  
Spiral Bevel

The coupled dynamic model of the intermediate and tail gearboxes’ spiral bevel gear-oblique tail shaft-laminated membrane coupling was established by employing the hybrid modeling method of finite element and lumped mass. Among them, the dynamic equation of the shaft was constructed by Timoshenko beam; spiral bevel gears were derived theoretically by the lumped-mass method, where the effects of time-varying meshing stiffness, transmission error, external imbalance excitation and the like were considered simultaneously; laminated membrane coupling was simplified to a lumped parameter model, in which the stiffness was obtained by the finite element simulation and experiment. On this basis, the laminated membrane coupling and effects of several important parameters, including the unbalance value, tail rotor excitation, oblique tail shaft’s length and transmission error amplitude, on the system’s dynamic characteristics were discussed. The results showed that the influences of laminated membrane coupling and transmission error amplitude on the coupled system’s vibration response were prominent, which should be taken into consideration in the dynamic model. Due to the bending-torsional coupled effect, the lateral vibration caused by gear eccentricity would enlarge the oblique tail shaft’s torsional vibration; similarly, the tail rotor’s torsional excitation also varies the lateral vibration of the oblique tail shaft. The coupled effect between the eccentricity of gear pairs mainly hit the torsional vibration. Also, as the oblique tail shaft’s length increased, the torsional vibration of the oblique tail shaft tended to diminish while the axis orbit became larger. The research provides theoretical support for the design of the helicopter tail transmission system.

A novel parallel algorithm for computing the mooring line based on lumped-mass method

2017 ◽  
Vol 08 (01) ◽  
pp. 1750004 ◽  
Author(s):  
Zhong-Xian Zhu ◽  
Yong Yin ◽  
Muhammad Mobeen Movania
Keyword(s):  
Parallel Algorithm ◽  
Real Time ◽  
Mooring Line ◽  
Dynamics Model ◽  
Graphic Processing Units ◽  
Lumped Mass ◽  
The Real ◽  
Runge Kutta Method ◽  
Lumped Mass Method ◽  
Speed Up

Dynamic modeling and simulation of the mooring system are the key technologies in anchor handling simulator (AHS). Built up the mooring line’s dynamics model based on lumped-mass method (LMM), and fourth-order Runge–Kutta method was used to solve the model; because of the huge amounts of calculation in the model’s solving, the very time-consuming process brings great impact on the real-time, fidelity and immersed feeling in the anchor handling scene simulation, seriously hindered its application in AHS. A novel parallel algorithm was proposed to speed-up the model’s solving process by taking the advantages of graphic processing units (GPU’s) massive parallel computing and float point computing capability. The model’s solving process was implemented on vertex shader based on the transform feedback (TF) mechanism in modern GPU. Experimental results show that, the new algorithm reduced the calculating time largely without losing accuracy, and can finally realize the real-time solving and simulation.

scholarly journals Influence of Shaft Torsional Stiffness on Dynamic Response of Four-Stage Main Transmission System

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yuan Chen ◽  
Rupeng Zhu ◽  
Guanghu Jin ◽  
Yeping Xiong
Keyword(s):  
Differential Equation ◽  
Fatigue Life ◽  
Dynamic Response ◽  
Fourier Method ◽  
Calculated Data ◽  
Transmission System ◽  
Torsional Stiffness ◽  
Response Analysis ◽  
Lumped Mass ◽  
Lumped Mass Method

Dynamic response analysis has potential for increasing fatigue life of the components in the transmission of a multistage main transmission system. The calculated data can demonstrate the influence of shaft torsional stiffness on dynamic characteristics of the system. Detecting key shafts of the system and analyzing their sensitivity are important for the design of four-stage helicopter gear box. Lumped mass method is applied for dynamic modeling and Fourier method is used to solve differential equation of the system. Results of the analysis indicate that key shafts can be designed carefully to improve the performance of the transmission system.

Modeling and Solving of Non-Linear Vibration Model of the Multi-Clearance and Bend and Torsion Coupled Gear-Driven System

2014 ◽  
Vol 1006-1007 ◽  
pp. 280-284
Author(s):  
Xing Han ◽  
Chang Li
Keyword(s):  
Fast Fourier Transformation ◽  
Analysis Model ◽  
Lumped Mass ◽  
Runge Kutta Method ◽  
Lumped Mass Method ◽  
Driven System ◽  
Non Linear ◽  
Phase Map ◽  
Tooth Flank ◽  
Fifth Order

Comprehensively taking the effects of variable rigidities, tooth flank clearances, bearing clearances, contact rigidities, and other multiple non-linear factors into account, it built a bend and torsion coupled gear-driven system’s dynamics analysis model in use of lumped mass method. After dimensionless dealing, it solved this dynamic model by the method of fifth order adaptive variable step (Runge-Kutta) method, and then it obtained system vibratory responses’ time domain diagrams, frequency domain diagrams, phase map, Poincare diagram, fast Fourier transformation (FFT) diagrams, and system branch diagrams under different parameters. All of them analyzed the effects of parameter variations on gearing system’s dynamic characteristics, and it provided a foundation for gearing system dynamic optimum designs.

Dynamic analysis of a helical gear reduction by experimental and numerical methods

2020 ◽  
Vol 68 (1) ◽  
pp. 48-58
Author(s):  
Chao Liu ◽  
Zongde Fang ◽  
Fang Guo ◽  
Long Xiang ◽  
Yabin Guan ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Fourth Order ◽  
Numerical Models ◽  
Helical Gear ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Lumped Mass ◽  
Gear Mesh

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.

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.

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.

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