Modal Analysis of Compressor Impeller with Crack and Blade Fracture

2013 ◽  
Vol 712-715 ◽  
pp. 1018-1021
Author(s):  
Mei Jiao Li ◽  
Hua Qing Wang ◽  
Wei Min Wang

The research of impeller dynamic characteristics by modal analysis technology is a kind of practical and effective fault diagnosis method, which has the vital significance to realize the security of machinery. Crack and blade fracture often occur in centrifugal compressor impeller. In order to study the impeller dynamic characteristic with crack and the blade fracture, a three-dimension finite element model (FEM) was built using ANSYS program, and an experimental modal analysis was also carried out. The compared results show that the preceding four orders natural frequencies and vibration models are basically consistent, and those also verified the reliability of the simulation results. In addition, two kinds of failure mode were also simulated, such as crack and blade fracture. It concluded that all orders natural frequencies decrease clearly, compared with the normal impeller. How the severity of crack and blade fracture affects the natural frequency was also discussed.

Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.


Author(s):  
Alexander O. Pugachev ◽  
Alexander V. Sheremetyev ◽  
Viktor V. Tykhomirov ◽  
Alexey V. Petrov

This paper describes a theoretical approach to shift individual natural frequencies of centrifugal compressor impeller blades. The approach applies sizing optimization of blade’s geometry using a gradient-based optimization method. Calculation of gradients is carried out by the finite-difference method. A new centrifugal compressor blade profile generator incorporating a blade parametrization procedure is developed. The blade’s geometry is parametrized using intuitive geometric parameters. Five design parameters related to the length of the sectional profile generator line, profile thicknesses and rotation angles at hub and shroud are defined for each of the blade sectional profiles. In addition, two global design parameters are defined to control rigid rotation of the blade hub and shroud sections in circumferential direction. Four nonlinear optimization problems containing multiple frequency constraints and constraints on the static equivalent stresses are considered. The optimization aims are either shifting a particular natural frequency of a blade or minimization of blade’s mass. For instance, one of the considered optimization problems is to decrease the 1st natural frequency of an impeller blade by 5%, while the 2nd and the 3rd natural frequencies must be simultaneously increased by 5%. The analysis is applied to the centrifugal compressor of a small-size turboprop engine. A three-dimensional finite element model of the impeller blade is developed in ANSYS Mechanical software package to perform static and modal analyses. The results of the optimization show that the code can meet defined objectives and constraints with reasonable accuracy. A detailed comparison of optimized profiles with the baseline geometry is provided.


2014 ◽  
Vol 607 ◽  
pp. 405-408 ◽  
Author(s):  
Wen Liu ◽  
Teng Jiao Lin ◽  
Quan Cheng Peng

The gear-shaft-bearing-housing coupled finite element model of marine gearbox was established by using the truss element, the spring element and the tetrahedral element. The modal of gearbox was analyzed by using the ANSYS software. Then through the experimental modal analysis, the natural frequencies of gearbox are obtained. Compare the experimental results with the numerical results, it shows good agreement.


2013 ◽  
Vol 645 ◽  
pp. 454-458
Author(s):  
Ming Hai Li ◽  
En Zhe Hong ◽  
Yu Guang Zhang

In order to understand the dynamic characteristics of 16V240 type diesel, established its solid model and finite element model. And conduct the modal analysis of 16V240 diesel with Lanczos method to get the natural frequencies and vibration mode. And then, find the weak points of 16V240 diesel for its structural redesign and improving.


2011 ◽  
Vol 50-51 ◽  
pp. 843-848 ◽  
Author(s):  
Quan Bai ◽  
Ke Xiang Wei ◽  
Wen Ming Zhang

Considered electrorheological (ER) elastomers as the visco-elasticity material, a finite element model of a sandwich beam filled with ER elastomers was developed based on Hamilton’s principle and sandwich beam’s theory. Then its dynamic characteristics were analyzed. Simulation results show that natural frequencies of the sandwich beam increase and vibration amplitudes of the beam decrease as the intensity of applied electric field increases. Increased the thickness of the ER elastomers layer, natural frequencies of the beam decrease and loss factors increase. Those indicate that the dynamic characteristic of ER elastomers sandwich beams is similar as that of ER fluids beam, which can be used for vibration control of flexible structures by applied a electric field.


2015 ◽  
Vol 757 ◽  
pp. 39-43
Author(s):  
Jian Feng Guo ◽  
Yi Na Feng ◽  
Yi Tao ◽  
Zhong Bao Qin ◽  
Chang Jiang Liu

Finite element model of dynamic tuned gyroscope (DTG) was founded using finite element software of ANSYS. Natural frequencies and vibration modalities of DTG in cases of both being static and rotating were studied respectively through the method of modal analysis, and also various vibration modalities influence on output of gyroscope was analyzed.


Author(s):  
Yasser Aktir ◽  
Jean-François Brunel ◽  
Philippe Dufrenoy ◽  
Hervé Mahe

Clutch system is an important element in the vehicle powertrain. It transmits the rotation from the crankshaft to the gearbox input shaft and filters axial and torsional vibrations providing from engine or induced by friction. This paper discusses axial dynamic behavior of automotive clutch for manual transmission. For this study, a tridimensional finite element model of clutch system is developed to simulate a clutch shaker test. First, an impact hammer test is performed to identify vibration properties of each clutch component. A pre-stressed modal analysis is then carried out to determine mode shapes and its associated natural frequencies of the clutch assembly. Shaker and simulation results are eventually compared to validate the clutch model. This latter offers for the design phase, a tool to avoid natural vibrations or to vibrate at specified frequencies.


2012 ◽  
Vol 152-154 ◽  
pp. 1183-1186
Author(s):  
Zhong Bao Qin ◽  
Guang Bin Liu ◽  
Jian Feng Guo ◽  
Xiao Long Hu

This paper proposed a method to analyses and obtain the vibration identities of DTG(Dynamically Tuned Gyroscope) within the vibration-overloading environment based on ANSYS11.0. Finite element model of DTG was constructed by ANSYS11.0. The Natural Frequencies and vibration modals of DTG in the cases of both being stationary and rotating were studied respectively through the method of modal analysis. The influence of each-rank vibration model of DTG on its output was investigated. The result of this paper provides a stable basis for improving the design of DTG and enhancing the functions of it.


2013 ◽  
Vol 353-356 ◽  
pp. 3541-3544
Author(s):  
Zhi Feng Nie ◽  
Xing Long Li

Finite element model of the main building of Zhaoguan coal preparation plant was established and its modal analysis was carried out based on ANSYS. The front six orders natural frequencies and modal shapes were calculated and the vibration characteristics were carried out. Results of modal analysis showed that the front six orders natural frequencies of the main building are between 1.7252 Hz to 5.1332Hz, which are far less than the working frequency of vibrating screen 15 Hz, so that the resonance phenomenon would not exist in the main building of the coal preparation plant.


2012 ◽  
Vol 229-231 ◽  
pp. 919-922
Author(s):  
Bao Dong Bai ◽  
Guo Hui Yang ◽  
Bing Yin Qu ◽  
Jian Zhang

In this paper, the modal analysis was carried out on the core and cavity of a 160KVA dry-type transformer based on the finite element analysis software of ANSYS. And the simulation results of the natural frequencies and modal shapes were obtained, which provided a theoretical guidance to the design of the transformer structure, and were meaningful to reduce the vibration and noise level of the transformer.


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