Bending Stiffness and Dynamic Characteristics of a Rotor With Spline Joints

2013 ◽  
Author(s):  
Fayong Wu ◽  
Zhichao Liang ◽  
Yanhong Ma ◽  
Dayi Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Bending Stiffness ◽  
Rotor System ◽  
Contact State ◽  
Structural Discontinuity ◽  
Aero Engine ◽  
Stiffness Characteristics ◽  
Stiffness Distribution ◽  
Engine Rotor

Spline is a kind of typical joint structures widely used in the aero-engine rotor system. The stiffness distribution of the spool is affected by the spline joint’s stiffness directly. Therefore, it is significant to investigate the spline joint’s stiffness characteristics and its influences on the dynamic characteristics of the rotor system. To figure out the factors that affect the bending stiffness of the spline joint, a mechanical model which takes contact state into account was built based on the structure analysis and force state analysis. In addition, an actual rotor with a spline joint was established to measure the stiffness under different loads, and the results were compared with the analysis by three modeling methods. Furthermore, the natural frequencies of the rotor were tested. Obtained results indicate that the structural discontinuity, the surface stiffness and the clearance fit cause the loss of local angular stiffness and linear stiffness. Meanwhile, the stiffness of the rotor with the spline joint is weaker along with the increase of the load/deformation, and become stable when undergoing the huge load/deformation. Besides, the local blending stiffness is presented as nonlinear and uncertainty subjected to an interval, which further affected the dynamic characteristics of rotor system.

Studies on dynamic characteristics of the joint in the aero-engine rotor system

2012 ◽  
Vol 29 ◽  
pp. 120-136 ◽  
Author(s):  
Liu Shuguo ◽  
Ma Yanhong ◽  
Zhang Dayi ◽  
Hong Jie
Keyword(s):  
Dynamic Characteristics ◽  
Rotor System ◽  
Aero Engine ◽  
Engine Rotor

A Study on the Effect of Bird Hit Damage on the Dynamic Response of Aero-Engine Fan Blade

2013 ◽  
Author(s):  
Hithesh Channegowda ◽  
Raghu V. Prakash ◽  
Anandavel Kaliyaperumal
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Foreign Object Damage ◽  
Aero Engine ◽  
Need To Evaluate ◽  
Bird Impact ◽  
Post Impact ◽  
Fan Blade ◽  
Critical Components

Fan blades of an aero-engine assembly are the critical components that are subjected to Foreign Object Damage (FOD) such as bird impact. Bird impact resulting in deformation damage onto set of blades, which in turn alters the blade mass and stiffness distribution compared to undamaged blades. This paper presents the numerical evaluation of dynamic characteristics of bird impact damaged blades. The dynamic characteristics evaluated are the natural frequencies and mode shapes of post impact damaged set of blades and the results are compared with undamaged set of blades. The frequencies and mode shapes are evaluated for the damaged blades, with varying angles of bird impact and three blade rotational speeds. Study reveals that first bending and torsional frequencies of deformed blades are significantly affected compared to undamaged set of blades. Study emphasize the need to evaluate the natural frequencies deformed blades, that has direct bearing on High Cycle Fatigue (HCF) life of the blade, to ensure post damaged blades operate safely for certain time to reduce inflight accidents and safe landing.

Multi Objective Optimisation of an Aero Engine Rotor System Using Nondominated Sorting Genetic Algorithm (NSGA)

2017 ◽  
Author(s):  
Joseph Shibu Kalloor ◽  
Ch. Kanna Babu ◽  
Girish K. Degaonkar ◽  
K. Shankar
Keyword(s):  
Genetic Algorithm ◽  
Critical Speed ◽  
Rotor System ◽  
Pareto Optimal ◽  
Multi Objective ◽  
Rayleigh Beam ◽  
Unbalance Response ◽  
Aero Engine ◽  
Nondominated Sorting ◽  
Engine Rotor

A comprehensive multi-objective optimisation methodology is presented and applied to a practical aero engine rotor system. A variant of Nondominated Sorting Genetic Algorithm (NSGA) is employed to simultaneously minimise the weight and unbalance response of the rotor system with restriction imposed on critical speed. Rayleigh beam is used in Finite Element Method (FEM) implemented in-house developed MATLAB code for analysis. The results of practical interest are achieved through bearing-pedestal model and eigenvalue based Rayleigh damping model. Pareto optimal solutions generated and best solution selected with the help of response surface approximation of the Pareto optimal front. The outcome of the paper is a minimum weight and minimum unbalance response rotor system which satisfied the critical speed constraints.

Vibration Characteristics Analysis of an Aero-Engine Turbine Blade

2012 ◽  
Vol 487 ◽  
pp. 894-897
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu ◽  
Qing Jun Guo
Keyword(s):  
Optimal Design ◽  
Turbine Blade ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Vibration Characteristic ◽  
Analysis Method ◽  
Aero Engine ◽  
Characteristics Analysis

This paper introduces the FEA method for a certain type of aero-engine turbine blade and makes a vibration characteristics analysis to this aero-engine turbine blade based on this method. The vibration characteristic of this aero-engine turbine blade is studied and the natural modal of the turbine blade is calculated based on UG software. The first six natural frequencies and mode shapes are given. According to the analysis results the dynamic characteristics of the blade are discussed. The analysis method and results in this paper can be used for further study on optimal design and vibration safety verification for the blade.

Dynamics Design of the Aero-Engine Rotor Joint Structures Based on Experimental and Numerical Study

2010 ◽  
Author(s):  
Shuguo Liu ◽  
Jun Wang ◽  
Jie Hong ◽  
Dayi Zhang
Keyword(s):  
Critical Load ◽  
Dynamic Characteristics ◽  
External Load ◽  
Structural Parameter ◽  
Contact State ◽  
Rotor Imbalance ◽  
Fatigue Damage Accumulation ◽  
Study Results ◽  
Aero Engine ◽  
Rotor Dynamic

This study investigated the rigidity and contact state of joint structures that influenced the rotor dynamic characteristics and imbalance response, and the curve for variable structure parameters and the external load. The consideration of rotor joint structures dynamics design was also discussed. The finite-element models were established by using 3D solid elements and surface-to-surface nonlinear contact elements between the interfaces for numerical analysis. The rotor dynamic characteristics were affected by the rigidity of joint structures, and the rotor imbalance response was affected by the contact state of the interfaces. The experimentation for measuring the static rigidity and dynamic contact state of bolted joints with different experimental cycles were performed. Both numerical simulation and experimental results showed that: Firstly, the stiffness of joint structures was not constant. There was a critical load Fcr, when the external load was less than Fcr, the stiffness of joint structures was K1; when the external load was more than Fcr, the bend stiffness of joint structures would drop to K2. The critical load Fcr was influenced by the length of interfaces and preload. Secondly, the contact state of joint structure interfaces varied after a long time of operating with alternating loads. The rotor imbalance was increased by fatigue damage accumulation and irreversible deformation. The study results show that the rigidity and contact state of joint structures vary with external loads and geometry structures, and would affect the rotor system operating. It is advisable to consider the influence of the position, structural parameter and external load of the rotor joint structures on aero-engine structure dynamics design.

FEA on Vibration Characteristics of a Shrouded Turbine Blade

2012 ◽  
Vol 189 ◽  
pp. 443-447
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu
Keyword(s):  
Optimal Design ◽  
Modal Analysis ◽  
Turbine Blade ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Software Environment ◽  
Aero Engine ◽  
Characteristics Analysis

This paper introduces a FEA method for vibration characteristics analysis of an aero-engine shrouded turbine blade and makes an actual modal analysis of this shrouded blade based on this method in UG software environment. The first six natural frequencies and mode shapes of this shrouded blade are calculated. And also, the dynamic characteristics of the shrouded turbine blade are discussed in detail according to the analysis results. The FEA method and the vibration characteristics analysis results in the paper can be used for optimal design and vibration safety verification of this aero-engine shrouded turbine blade.

Performance Simulation for the Supporting Structure of Aero-Engine Rotor in Wide Frequency Domain

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Baoxu Li
Keyword(s):  
Finite Element ◽  
Frequency Domain ◽  
Dynamic Characteristics ◽  
Stiffness Matrix ◽  
Structural Model ◽  
Test Method ◽  
Supporting Structure ◽  
Aero Engine ◽  
Rotor Support ◽  
Engine Rotor

The inertia load of aero-engine indeterminate rotor support is calculated by the finite element method coupled with plane stress element and Fourier ring element. Without considering the dynamic characteristics of rotor’s supporting structure, the test results are error-prone and inefficient. A new method for testing the supporting structure performance of aero-engine rotor in wide frequency domain is proposed. On this basis, the structural model of the casing-support and the structural model of aero-engine rotor are constructed by substructure modelling method. Combining the two sub-models, the semi-physical simulation model of the vibration of the engine rotor’s supporting structure is obtained. By superimposing the additional dynamic stiffness matrix of the casing-supporting structure at the designated DOF position in the overall stiffness matrix of the finite element model of the rotor structure, the overall stiffness matrix of the aero-engine rotor supporting structure is obtained. The effective stiffness matrix can be used to calculate the structural dynamic characteristics of aero-engine rotor supporting structure. Experiments show that the average error of the proposed method is 0.0023 and the number of units is 7.98 e4. The calculation time and storage space are reduced by 310 minutes and 166 GB respectively compared with the performance test method of rotor support based on finite element analysis, which shows that the proposed method is more efficient and accurate.

Modelling of Misaligned Rotor System in Aero-Engines and Interval Method Investigation

2013 ◽  
Author(s):  
Guihua Wang ◽  
Yanhong Ma ◽  
Tianrang Li ◽  
Jun Li ◽  
Jie Hong
Keyword(s):  
Dynamic Response ◽  
Rotor System ◽  
Mechanical Parameters ◽  
Lagrange Method ◽  
Interval Method ◽  
Aero Engine ◽  
Mechanical Factors ◽  
Aero Engines ◽  
Rotor Model ◽  
Engine Rotor

Based on the structural and dynamic characteristics of aero-engine rotor system, we used Lagrange method to develop a two-bearing and a multi-bearing rotor model with misalignment. An equation of motion was derived with features of response examined. Due to the uncertainty of mechanical parameters, interval method was adopted to investigate the dynamic response of rotor system with misalignment. Dynamic response and influence of the key mechanical parameters will be obtained in further research. The two times harmonic was found as a distinctive feature of misalignment and the magnitude of it in spectrum is closely related to some key mechanical factors. We also found interval method outstandingly performed in investigating dynamic response when some key parameters are uncertain.

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