Analysis and enhancement of torsional vibration stopbands in a periodic shaft system

2013 ◽  
Vol 46 (14) ◽  
pp. 145306 ◽  
Author(s):  
Yubao Song ◽  
Jihong Wen ◽  
Dianlong Yu ◽  
Xisen Wen
Keyword(s):  
Torsional Vibration ◽  
Shaft System

Analysis of Models for Torsional Vibration of Shaft System With Planetary Gearing

1997 ◽  
Author(s):  
Jinghui Sun ◽  
Lee Liu ◽  
William N. Patten
Keyword(s):  
Torsional Vibration ◽  
Planetary Gear ◽  
Gear Train ◽  
Mathematical Treatment ◽  
Dynamic Parameters ◽  
Mass Model ◽  
Planar Model ◽  
Shaft System ◽  
Effective Dynamic ◽  
Single Mass

Abstract The kinematics of planetary gearing are complex; thus, making it difficult to build an effective dynamic model. In this paper, a single-mass model of a planetary gear and shaft system is developed to study the torsional vibration of the mechanism. Two new models of the system are proposed: (a) a fictitious co-planar model and (b) an equivalent shaft model. The results from the calculations and analyses using these models indicate that: 1) the single-mass model and the general rotary model are both limited, either mathematically or geometrically; 2) the fictitious co-planar model includes all of the geometric and dynamic parameters of the general rotary model, and it can be connected with the shaft system easily; and 3) using a mathematical treatment, the equivalent shaft model is demonstrated to be the most useful and most effective model for the calculation of torsional vibration of a shaft and planetary gear train.

Torsional Vibration Analysis and Stress Calculation for the Fault 600MW Steam Turbine Generator Shaft System

2009 ◽  
Author(s):  
Dongxiang Jiang ◽  
Liangyou Hong ◽  
Zheng Wang ◽  
Xiaorong Xie
Keyword(s):  
Steam Turbine ◽  
Torsional Vibration ◽  
Operation Condition ◽  
Turbine Generator ◽  
Modal Shape ◽  
Subsynchronous Oscillation ◽  
Root Cause ◽  
Shaft System ◽  
Mass Element ◽  
Rotor Dynamic

Subsynchronous oscillation (SSO) or torsional vibration may cause shaft of steam turbine generator hurt heavily. This phenomenon has destroyed two generator shafts in one of China’s power plant in 2008. Detailed analysis and several measurements have been taken to identify the reason of the accident. First, the operational data is analyzed, including field torsional vibration dada. Then, the modal of the shaft system is calculated. Each torsional vibration frequency is gotten with corresponding modal shape. Dangerous location of the shaft system is obtained. Third, torque value of different operation condition is calculated based on two different models: one is traditional multiple mass element rotor dynamic model and the other is an four mass element electromechanical model of rotor oscillation. Following, the maximum stress on the dangerous location is calculated using finite element method. Finally, the root cause of shaft destruction is analyzed and identified.

Derivatives of Eigenvalues for Torsional Vibration of Geared Shaft Systems

1993 ◽  
Vol 115 (3) ◽  
pp. 277-279 ◽  
Author(s):  
Liu Zhong-Sheng ◽  
Chen Su-Huan ◽  
Xu Tao
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Natural Frequency ◽  
Torsional Vibration ◽  
Design Parameter ◽  
Practical Importance ◽  
Design Sensitivity ◽  
Shaft System ◽  
Eigenvalue Derivatives ◽  
Derivatives Of

Design sensitivity analysis of natural frequency for geared shaft systems is of practical importance in the optimal design of these systems. This note provides a simple and easily implemented method to calculate the eigenvalue derivatives of a geared shaft system with respect to a design parameter ν, including gear inertia J, shaft stiffness K, and transmission ratio Q, when the eigensolution is known. An example is given to illustrate the method.

scholarly journals Design Improvement of a Viscous-Spring Damper for Controlling Torsional Vibration in a Propulsion Shafting System with an Engine Acceleration Problem

2020 ◽  
Vol 8 (6) ◽  
pp. 428
Author(s):  
Jaehoon Jee ◽  
Chongmin Kim ◽  
Yanggon Kim
Keyword(s):  
Torsional Vibration ◽  
Exciting Force ◽  
Design Parameters ◽  
Reduce Fuel Consumption ◽  
Propulsion Efficiency ◽  
Design Improvement ◽  
Shaft System ◽  
Long Stroke ◽  
Marine Environmental ◽  
Stroke Engine

In order to cope with strengthened marine environmental regulations and to reduce fuel consumption, recently constructed vessels are equipped with an ultra-long stroke engine and apply engine de-rating technology. This was intended to improve propulsion efficiency by adopting a larger diameter propeller turning at a lower speed but also results in a significant increase in the torsional exciting force. Therefore, it is very difficult to control the torsional vibration of its shaft system by adopting a damper, for ships equipped with fuel-efficient ultra-long-stroke engines, even though previously, torsional vibration could be controlled adequately by applying tuning and turning wheels on the engine. In this paper, the vibration characteristics of an ultra-long-stroke engine using the de-rating technology are reviewed and dynamic characteristics of a viscous-spring damper used to control the torsional vibration of its shaft system are also examined. In case of ships have recently experienced an engine acceleration problem in the critical zone, it is proposed that the proper measures for controlling torsional vibration in the propulsion shafting system should include adjusting the design parameters of its damper instead of using the optimum damper designed from theory in order to prevent fatigue fracture of shafts.

Vibration of diesel-electric hybrid propulsion system with nonlinear component

2018 ◽  
Vol 24 (22) ◽  
pp. 5353-5365 ◽  
Author(s):  
Nengqi Xiao ◽  
Ruiping Zhou ◽  
Xiang Xu
Keyword(s):  
Mathematical Model ◽  
Theoretical Calculation ◽  
Torsional Vibration ◽  
Calculation Method ◽  
Propulsion System ◽  
Vibration Test ◽  
Hybrid Propulsion ◽  
Harmonic Method ◽  
Shaft System ◽  
Marine Diesel

The lumped parameter method is used to model the components of a marine diesel-electric hybrid propulsion system. Modular modeling and five basic models of torsional vibration are used to establish the torsion of the diesel-electric hybrid propulsion system with a nonlinear components vibration mathematical model. In order to include the nonlinear parts of the marine diesel-hybrid propulsion shafting torsional vibration system characteristics, by combining the perturbation method with the advantages and disadvantages of the harmonic method, a perturbation-harmonic method is presented to solve the diesel-electric hybrid propulsion shafting free vibration characteristics. At the same time, the nonlinear vibration characteristics of the hybrid propulsion shaft system are calculated and analyzed using the incremental harmonic balance method. In order to verify the correctness of the theoretical method of hybrid propulsion system, the correctness of the vibration model and method is verified by carrying out actual tests on a 10,000-ton marine surveillance ship. In order to verify the mathematical model of the ship diesel-hybrid propulsion system and the correctness of the theoretical calculation method, the torsional vibration test is carried out by a strain gauge method for a 10,000-ton marine propulsion shaft. The correctness of the torsional vibration mathematical model and the calculation method is verified by comparing the torsional vibration test data and the theoretical calculation data of the ship propulsion shaft system, which provides the theoretical significance for the calculation and analysis of the torsional vibration of the ship propulsion shaft system.

Solution for the torsional vibration of the compressor shaft system with flexible coupling based on a sensitivity study

2018 ◽  
Vol 233 (4) ◽  
pp. 803-812
Author(s):  
Jianmei Feng ◽  
Ying Zhao ◽  
Xiaohan Jia ◽  
Xueyuan Peng
Keyword(s):  
Torsional Vibration ◽  
Sensitivity Study ◽  
Calculation Model ◽  
Mode Shapes ◽  
Primary Data ◽  
Elastic Model ◽  
Lumped Mass ◽  
Shaft System ◽  
Speed Fluctuation ◽  
One Year

This paper presents the root cause analysis and solving process of the torsional vibration problem in a reciprocating compressor shaft system. The field measured data showed that the fifth-order torsional resonance occurred in the shaft system. The lumped-mass method was adopted to calculate the torsional natural frequencies (TNFs) and mode shapes of the shaft system. A sensitivity study was conducted to investigate the effect of each inertia and stiffness in the calculation model on the first TNF of the shaft system. The uncertainties of the primary data of the calculation model were discussed, and the mass-elastic model was modified by adjusting the stiffness of the flexible disc coupling. After adding an inertia of 4.68 kg·m2, torsional resonance was avoided, and the speed fluctuation of the shaft system was significantly reduced. The compressor package has been operating normally for nearly one year after modification. The analysis methods and conclusions given here can provide guidance for trouble-shooting torsional vibration problems.

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