Sensitivity Analysis of Natural Frequency to Structural Parameters of Helical Gear Shaft for Wind Turbine Gearbox

2011 ◽  
Vol 86 ◽  
pp. 380-383 ◽  
Author(s):  
Jun Gang Wang ◽  
Yong Wang ◽  
Yan Tao An ◽  
Qi Lin Huang
Keyword(s):  
Sensitivity Analysis ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Structural Parameters ◽  
Helical Gear ◽  
Research Subject ◽  
Wind Turbine Gearbox ◽  
Frequency Sensitivity ◽  
Helical Angle ◽  
The Relationship

This paper takes a helical gear shaft as research subject and discusses the main structural parameters to see how it would affect natural frequency sensitivity. The parametrical model of helical gear shaft is created by using software PROE3.0. The natural frequencies and vibration shapes are calculated by the modal analysis. The relationship between the structural parameters and the natural frequency sensitivity can be obtained by means of ANSYS. The result shows that the structural parameters can affect the natural frequency sensitivity. The variation in low order natural frequency is similar to that in high order natural frequency. The effect of module on the natural frequency sensitivity is more remarkable comparing with pressure angle, modification coefficient and helical angle. Selecting structural parameters reasonably may reduce vibration and noise of the helical gear shaft effectively.

Sensitivity Analysis and Application of Natural Frequency of Torsional Vibration of Rotor System

2008 ◽  
Author(s):  
Qing He ◽  
Dongmei Du
Keyword(s):  
Sensitivity Analysis ◽  
Electric Power ◽  
Natural Frequency ◽  
Torsional Vibration ◽  
Natural Frequencies ◽  
Electric Power System ◽  
Rotor System ◽  
Analysis Method ◽  
Turbine Generator ◽  
Sensitivity Analysis Method

The disturbance of electric power system makes large-scale turbine-generator shafts generate torsional vibration. A available method to restrain the torsional vibration of turbine-generator shafts is that all the natural frequencies of torsional vibration of turbine-generator shafts must keep away from the working frequency and its harmonic frequencies as well as all the frequencies that possibly bring on interaction between turbine-generator and electric power system so that the torsional resonation of shafts may not occur. A dynamic design method for natural frequencies of torsional vibration of rotor system based on sensitivity analysis is presented. The sensitivities of natural frequency of torsional vibration to structure parameters of rotor system are obtained by means of the theory of sensitivity. After calculated the torsional vibration dynamic characteristics of original shafts of a torsional vibration stand that simulates the real shafts of 300MW turbine-generator, the dynamic modification for the torsional vibration natural frequency is carried out by the sensitivity analysis method, which makes the first-five natural frequencies of torsional vibration of the stand is very close to the design object. It is proved that the sensitivity analysis method can be used to the dynamic adjustment and optimal design of real shafts of turbine-generator.

Natural Frequency Sensitivity Analysis with Respect to Lumped Mass Location

AIAA Journal ◽  
10.2514/2.812 ◽  
1999 ◽  
Vol 37 (8) ◽  
pp. 928-932 ◽  
Author(s):  
D. C. D. Oguamanam ◽  
Z. S. Liu ◽  
J. S. Hansen
Keyword(s):  
Sensitivity Analysis ◽  
Natural Frequency ◽  
Lumped Mass ◽  
Frequency Sensitivity

scholarly journals ALGORITHM FOR CONTROLLING THE SPECTRUM OF EIGENFREQUENCIES AND VIBRATION MODES BY CHARDING THE GEOMETRIC PARAMETERS OF MAST SESTEMS

2021 ◽  
pp. 6-18
Author(s):  
Vladimir Grinyov ◽  
Vitaliy Vynogradov
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Maximum Principle ◽  
Optimality Conditions ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Maximum Principle ◽  
Natural Frequency Spectrum

The article considers a model of a mast with six levels of fastening of cables. The main attention in the work is considered to the methods of control of the natural frequency spectrum, due to the use of methods of sensitivity analysis and optimization. The above task is achieved by varying the cross-sectional area of the pipes - racks. Automation of computational processes is provided by programming the built-in module in the Revit program. For more convenient and faster control of the natural frequency spectrum, the algorithm described above was written in a free add-on for Revit - Dynamo. With the help of so-called nodes, an application was created that took data from the depicted 3D model Revit and performed calculations. This allows you to easily use optimality conditions similar to the maximum principle. The sensitivity analysis for the first and second own is carried out in the work. The mechanism of their management within the limits of the investigated model is shown. The relations in the case of the problem of finding the natural frequency extremum with a given number are given, provided that the total amount of varied bands is fixed. The numerical control algorithm is based on the necessary optimality conditions in the form of the maximum principle for rod models. A variant of varying the area of the belts along the height of the mast is proposed. The sensitivity analysis for the first and second natural frequencies is carried out and its use for construction of effective computational process is shown. Based on the results of the work, a working software algorithm was created for fast analysis of mast oscillations on extensions. Graphs of zones of possible change of the first and second frequencies are resulted. The distribution of the cross-sectional area for frequencies is shown. To compare the results of natural frequency calculations on other calculation models, the first and second natural frequencies of bending oscillations were calculated by the finite element method in the SCAD complex. The errors for the points of the curves (constant in the height of the mast area of the belts) do not exceed 10%. It should be noted that the consideration of optimization problems of the above type on the basis of finite element models is quite difficult; for them it is not possible to formulate the necessary conditions of optimality similar to the principle of maximum.

scholarly journals Identification of Debonding Damage at Spar Cap-Shear Web Joints by Artificial Neural Network Using Natural Frequency Relevant Key Features of Composite Wind Turbine Blades

2021 ◽  
Vol 11 (12) ◽  
pp. 5327
Author(s):  
Yun-Jung Jang ◽  
Hyeong-Jin Kim ◽  
Hak-Geun Kim ◽  
Ki-Weon Kang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Structural Integrity ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Artificial Neural ◽  
The Relationship

As the size and weight of blades increase with the recent trend toward larger wind turbines, it is important to ensure the structural integrity of the blades. For this reason, the blade consists of an upper and lower skin that receives the load directly, a shear web that supports the two skins, and a spar cap that connects the skin and the shear web. Loads generated during the operation of the wind turbine can cause debonding damage on the spar cap-shear web joints. This may change the structural stiffness of the blade and lead to a lack of integrity; therefore, it would be beneficial to be able to identify possible damage in advance. In this paper we present a model to identify debonding damage based on natural frequency. This was carried out by modeling 1105 different debonding damages, which were classified by configuration type, location, and length. After that, the natural frequencies, due to the debonding damage of the blades, were obtained through modal analysis using FE analysis. Finally, an artificial neural network was used to study the relationship between debonding damage and the natural frequencies.

Parametric Design Study About Seismic Isolation System for Fast Reactor JSFR

2015 ◽  
Author(s):  
Nobuchika Kawasaki ◽  
Tomohiko Yamamoto ◽  
Tsuyoshi Fukasawa ◽  
Shigeki Okamura
Keyword(s):  
Natural Frequency ◽  
Seismic Isolation ◽  
Natural Frequencies ◽  
Parametric Design ◽  
Acceleration Response ◽  
Isolation System ◽  
Expansion Characteristic ◽  
Main Component ◽  
Relationship Of ◽  
The Relationship

Japanese seismic conditions are getting severer and natural frequencies of components are getting lower due to the enlargements of components’ size, therefore response accelerations and buckling margins of reactor vessels were parametrically surveyed with attention to thicknesses, diameters, and isolation frequencies for reviewing necessary isolation specification. For the first, Japanese seismic condition and present specification of JSFR isolation system are introduced in this paper. RV installed floor responses were calculated based on this seismic condition and the relationship of natural frequencies, initiated stresses, and buckling margins against vessel thicknesses and diameters were shown with trend. Expansion characteristic of isolation system was evaluated by parametric acceleration response analyses. Comparing the response of isolation system with 8Hz vertical natural frequency with other natural frequency’s isolation, response ratios against natural frequencies were calculated. Japanese seismic design condition may become severer than present one, and a natural frequency of main component may decrease. However based on the buckling margin with present plant specifications and the expansion characteristic of isolation system, the advanced isolation system with 8Hz vertical natural frequency was selected as the isolation system of JSFR at still present occasion.

Natural frequency sensitivity analysis with respect to lumped mass location

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 928-932 ◽  
Author(s):  
D. C. D. Oguamanam ◽  
Z. S. Liu ◽  
J. S. Hansen
Keyword(s):  
Sensitivity Analysis ◽  
Natural Frequency ◽  
Lumped Mass ◽  
Frequency Sensitivity

Reliability Evaluation of Glass Curtain Wall via Vibration Detection

2011 ◽  
Vol 492 ◽  
pp. 410-414 ◽  
Author(s):  
Xiao Gen Liu ◽  
Yi Wang Bao
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Safety Evaluation ◽  
Service Capacity ◽  
Curtain Wall ◽  
Vibration Detection ◽  
Glass Specimen ◽  
Glass Curtain Wall ◽  
Frequency Changes ◽  
The Relationship

Developing efficient onsite damage detection and safety evaluation methods for glass curtain wall is still a challenging task. In this work, a simple approach to predict the failure and risk of falling down of curtain wall glass was developed through the relationship between the natural frequency changes and the declined reliability of the structures. Natural frequencies of the curtain wall glass under various clamping conditions were determined using dynamic tests. It was discovered that, with the decrease of the clamping force at the boundary of the glass specimen, the measured natural frequencies decreased linearly. Thus, the in-service capacity in edge clamping (e.g. boundary is loosed or failure of the supporting structure) of the curtain wall glass can be identified by its natural frequency changes. The expected lowest safety natural frequency of a curtain wall glass (given elastic parameters, shape and size) is given. The implementation of this detection method is described, and the practicability and feasibility validated.

Sensitivity Analysis of 1000MW USC Units Shafting Torsional Vibration Based on ANSYS

2012 ◽  
Vol 226-228 ◽  
pp. 162-165
Author(s):  
Shi Liu ◽  
Cong Wang ◽  
Bing Li ◽  
Chang Chen ◽  
Dan Mei Xie
Keyword(s):  
Sensitivity Analysis ◽  
Natural Frequency ◽  
Torsional Vibration ◽  
Structural Parameters ◽  
Vibration Characteristics ◽  
Moment Of Inertia ◽  
Safe Operation ◽  
Important Significance

To calculate a shaftings natural frequency of torsional vibration is one of the most important tasks in turbo-generators design, manufacture and frequency adjusting process. The sensitivity analysis of shafting structural parameters impact on the torsional vibration characteristics has important significance in reducing the amplitude of torsional vibration and ensuring the turbo-generators safe operation. In this paper, a 1000MW USC unit was taken as a research object to analyze the shaftings sensitivity to moment of inertia.

scholarly journals Natural Frequency Sensitivity Analysis of Fire-Fighting Jet System with Adaptive Gun Head

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 808 ◽  
Author(s):  
Xiaoming Yuan ◽  
Xuan Zhu ◽  
Chu Wang ◽  
Lijie Zhang ◽  
Yong Zhu
Keyword(s):  
Sensitivity Analysis ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Fire Fighting ◽  
Mode Analysis ◽  
Mode Shapes ◽  
Design Parameters ◽  
Parameter Method ◽  
First Order ◽  
Typical Design

The gun head is the end effector of the fire-fighting jet system. Compared with a traditional fixed gun head, an adaptive gun head has the advantages of having an adjustable nozzle opening, a wide applicable flow range, and a high fire-extinguishing efficiency. Thus, the adaptive gun head can extinguish large fires quickly and efficiently. The fire-fighting jet system with an adaptive gun head has fluid-structure interaction and discrete-continuous coupling characteristics, and the influence of key design parameters on its natural frequencies needs to be determined by a sensitivity analysis. In this paper, the dynamic model and equations of the jet system were established based on the lumped parameter method, and the sensitivity calculation formulas of the natural frequency of the jet system to typical design parameters were derived. Natural frequencies and mode shapes of the jet system were determined based on a mode analysis. The variation law of the sensitivity of the natural frequency of the jet system to typical design parameters was revealed by the sensitivity analysis. The results show that the fluid mass inside the spray core within a certain initial gas content is the most important factor affecting the natural frequency of the jet system. There was only a 0.51% error between the value of the first-order natural frequency of the jet system determined by the modal experiment and the theoretical one, showing that good agreement with the first-order natural frequency of the jet system was found. This paper provides a theoretical basis for the dynamic optimization design of the adaptive gun head of the fire water monitor.

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