The Bending Vibration Analysis on the Main Drive Axis of CNC Spiral Bevel Gear Milling Machine

2013 ◽  
Vol 655-657 ◽  
pp. 1296-1299
Author(s):  
Li Juan Yu ◽  
Zhao Jun Yang ◽  
Fu You Liu
Keyword(s):  
Drive Shaft ◽  
Resonance Problem ◽  
Parameter Method ◽  
Force Model ◽  
Lumped Mass ◽  
Mass Model ◽  
Bending Vibration ◽  
Lumped Parameter ◽  
Lumped Mass Model ◽  
Lumped Parameter Method

Gear machine tool main drive shaft to avoid resonance problem is studied.The force of the drive shaft is analyzed, and the vibration form of the drive shaft is confirmed. Using the lumped parameter method to simplify the main drive shaft, the lumped mass model and the force model were been obtained. When bending vibrating, the natural frequency of the main drive shaft is calculated using the transfer matrix method. The calculated critical speed is 43755r/min, which far outweighs the motor rated speed .It means that the drive shaft under normal work won't be resonance, which accords with the request of production.

On the Analytical Lumped-Mass Model of an Elastic Four-Bar Mechanism

1975 ◽  
Vol 97 (2) ◽  
pp. 561-565 ◽  
Author(s):  
J. P. Sadler
Keyword(s):  
Nonlinear Differential Equations ◽  
Beam Theory ◽  
Parameter Method ◽  
Lumped Mass ◽  
Mass Model ◽  
Bending Vibration ◽  
Lumped Parameter ◽  
Lumped Mass Model ◽  
Four Bar Linkage ◽  
Euler Bernoulli Beam

The lumped-parameter method for the elastodynamic analysis of mechanisms is applied to a particular case for which existing experimental evidence is available. The mechanism analyzed is a planar four-bar linkage, and the calculated results include steady-state deflection and stress and strain responses associated with the bending vibration of the three moving links. The analytical model is based on nonlinear differential equations derived by way of Euler-Bernoulli beam theory, and numerical solution is obtained through the use of a digital computer. Comparison of the analytical and experimental results shows very good agreement, supporting the use of the lumped-parameter approach in analyses of this type.

The Drive Axis Simulate Analysis on the Spiral Bevel Gear Milling Machine

2013 ◽  
Vol 365-366 ◽  
pp. 281-284
Author(s):  
Li Juan Yu ◽  
Xu Peng Li ◽  
Fu You Liu ◽  
Fei Zheng
Keyword(s):  
Bevel Gear ◽  
Drive Shaft ◽  
Parameter Method ◽  
Spiral Bevel Gear ◽  
Force Model ◽  
Milling Machine ◽  
Feed System ◽  
Lumped Mass ◽  
Mass Model ◽  
Spiral Bevel

The tool feed system main drive shaft of CNC spiral bevel gear milling machine is researched, and the vibration form of the drive shaft is confirmed.The main drive shaft is simplified using the lumped parameter method, the lumped mass model and the force model were been obtained. When bending vibrating, the natural frequency of the main drive shaft is calculated using the transfer matrix method. In order to verify the correctness of the calculations, the vibration of the main drive shaft is simulated by using ANSYS. This paper also designs the vibration control system for the main drive shaft, and analyzes influence factors which affects the vibration of the main drive shaft.

Active Control of Wind-Induced Building Vibration Using a Linear Coupling Strategy

2001 ◽  
Author(s):  
S. Mohammad Hashemi ◽  
M. F. Golnaraghi
Keyword(s):  
Control System ◽  
Active Control ◽  
Lumped Parameter Model ◽  
Test Bed ◽  
Lumped Mass ◽  
Mass Model ◽  
Linear Coupling ◽  
Lumped Parameter ◽  
Coupling Strategy ◽  
Lumped Mass Model

Abstract The active control of building vibration is addressed. The aeroelastic lumped mass model of a building is designed to be used as the test bed for the active control system. The five story lumped parameter model was modeled as a cantilever beam exhibiting planar vibration. A Linear Coupling Control (LCC) strategy was implemented to eliminate the vibrations. An active (moving) mass damper (AMD) was first designed and experimentally implemented to control the first mode vibration of the system. An alternative pendulum control system was then designed and implemented. The proposed pendulum, having three times smaller mass than the AMD, was found to be more effective in reducing the building vibrations.

A Comparison of Inverse Models for the Estimation of Ice-Induced Propeller Moments on a Polar Vessel

2021 ◽  
Author(s):  
Brendon M. Nickerson ◽  
Anriëtte Bekker
Keyword(s):  
Rotational Speed ◽  
Continuous Model ◽  
Full Scale ◽  
Lumped Mass ◽  
Mass Model ◽  
Inverse Models ◽  
Lumped Mass Model ◽  
Ill Posed ◽  
Shaft Torque ◽  
Measurement Location

Abstract Full-scale measurements were conducted on the port side propulsion shaft the S.A. Agulhas II during the 2019 SCALE Spring Cruise. The measurements included the shaft torque captured at two separate measurement locations, and the shaft rotational speed at one measurement location. The ice-induced propeller moments are estimated from the full-scale shaft responses using two inverse models. The first is a published discrete lumped mass model that relies on regularization due to the inverse problem being ill-posed. This model is only able to make use of the propulsion shaft torque as inputs. The second model is new and employs modal superposition to represent the propulsion shaft as a combination of continuous modes, resulting in a well-posed problem. This new model requires the additional measurement of the shaft rotational speed for the inverse solution. The continuous model is shown to be more consistent and efficient, which allows its use in real-time monitoring of propeller moments.

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.

Identification of firefly algorithm-based fluctuation coefficient of the exciting torque for vehicle driveline

2018 ◽  
Vol 233 (2) ◽  
pp. 317-326
Author(s):  
Qiaobin Liu ◽  
Wenku Shi ◽  
Zhiyong Chen
Keyword(s):  
Torsional Vibration ◽  
Firefly Algorithm ◽  
Vibration Response ◽  
Theoretical Modelling ◽  
Lumped Mass ◽  
Mass Model ◽  
Engine Torque ◽  
Lumped Mass Model ◽  
Vibration Performance ◽  
Engine Excitation

The unbalanced excitation force and torque generated by an engine that resonate with the natural frequency of drivetrain often causes vibration and noise problems in vehicles. This study aims to comprehensively employ theoretical modelling and experimental identification methods to obtain the fluctuation coefficients of engine excitation torque when a car is in different gear positions. The inherent characteristics of the system are studied on the basis of the four-degree-of-freedom driveline lumped mass model and the longitudinal dynamics model of vehicle. The correctness of the model is verified by torsional vibration test. The second order's engine torque fluctuation coefficients are identified by firefly algorithm according to the curves of flywheel speed in different gears under the acceleration condition of the whole open throttle. The torque obtained by parameter identification is applied to the model, and the torsional vibration response of the system is analysed. The influence of the key parameters on the torsional vibration response of the system is investigated. The study concludes that proper reduction of clutch stiffness can increase clutch damping and half-axle rigidity, which can help improve the torsional vibration performance of the system. This study can provide reference for vehicle drivetrain modelling and torsional vibration control.

An improved lumped parameter method for calculating static characteristics of multi-recess hydrostatic journal bearings

2019 ◽  
Vol 234 (2) ◽  
pp. 301-310
Author(s):  
Yongtao Zhang ◽  
Shijie Yu ◽  
Changhou Lu ◽  
Haixia Zhao ◽  
Peng Liang
Keyword(s):  
Total Pressure ◽  
Control Volume ◽  
Journal Bearings ◽  
Parameter Method ◽  
Static Characteristics ◽  
Application Range ◽  
Continuity Equations ◽  
Pressure Distributions ◽  
Lumped Parameter ◽  
Lumped Parameter Method

This paper proposes an improved lumped parameter method for calculating the static characteristics of multi-recess hydrostatic journal bearings. The improved lumped parameter method can estimate the total pressure distribution in the circumferential direction by introducing control volume in the middle of each inter-recess land, and utilizing the flow continuity equations for each recess and each control volume with the assumption that the pressure distributions are parabolic on the inter-recess land. Then the recess pressure and the fluid film force can be calculated. The calculation accuracy of the improved lumped parameter method and the traditional lumped parameter method is comparatively discussed under different eccentricity ratios and wrap angles of the recess. The results show that the improved lumped parameter method has higher calculation accuracy and wider application range.

scholarly journals Analysis and Application of Screens for Acoustic Impedance in a Speaker Box with a Passive Radiator to Decrease Standing-Wave Influence

2020 ◽  
Vol 10 (3) ◽  
pp. 866
Author(s):  
Yuan-Wu Jiang ◽  
Dan-Ping Xu ◽  
Zhi-Xiong Jiang ◽  
Jun-Hyung Kim ◽  
Ki-Hong Park ◽  
...  
Keyword(s):  
Standing Wave ◽  
Acoustic Resonance ◽  
Experimental Result ◽  
Parameter Method ◽  
Analysis Tool ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Lumped Parameter ◽  
Acoustic Domain ◽  
Lumped Parameter Method

Micro speakers are playing an increasingly important role with the development of multimedia devices. This study applies the lumped-parameter method, which uses an equivalent circuit to model the electromagnetic and mechanical domains. The acoustic domain is modeled using the finite element method. Based on the analysis tool, the use of a screen is analyzed, and the screen is designed to depress the acoustic resonance in the sound-pressure-level curve and improve the performance. The samples are fabricated, and the experiment verifies the analysis method. The experimental result shows that the peak and dip due to the standing wave are cancelled, and the frequency response is smooth when the screen is used.

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