A Mistuning Sensitivity Suppression Method of Bladed Disk

2012 ◽  
Vol 479-481 ◽  
pp. 1350-1354
Author(s):  
Yi Xuan Li ◽  
Chuang Shao ◽  
Zhi Jun Zhang
Keyword(s):  
Element Model ◽  
Vibration Response ◽  
Modal Shape ◽  
Free System ◽  
Response Characteristics ◽  
Bladed Disk ◽  
Lumped Parameter ◽  
Random Mistuning ◽  
Suppression Method ◽  
Shape Characteristics

Based on the lumped parameter modal, the modal shape characteristics of the tuned free bladed disk and the random mistuned bladed disk was studied. It can be concluded that the vibration energy is evenly distributed in the tuned free system, but in the mistuned system, the modal localization dose exist. And the localization degree gets stronger while the mistuning strength is bigger .Then based on the finite element model of a bladed disk. The intentional mistuning technology’s role in reducing the sensitivity of the bladed disk to random mistuning was studied in this paper. The blades vibration response characteristics and the intentional mistuning technology was also studied through magnification factor for amplitude and localization factor. The result shows that the mistuning sensitivity level can be reduced by adding the quantity of intentional mistuning, and intentional mistuning has an important meaning to reduce the adverse effect of the random mistuning to the blades vibration response.

Vibration Localization Analysis of Bladed Disk with Grouped Blades

2010 ◽  
Vol 139-141 ◽  
pp. 2307-2311
Author(s):  
Ai Lun Wang ◽  
Bo Hai Sun ◽  
Jin Bo Chen
Keyword(s):  
Natural Frequency ◽  
Vibration Localization ◽  
Bladed Disk ◽  
Lumped Parameter ◽  
Lumped Parameter Models ◽  
Periodic Groups ◽  
Localization Analysis ◽  
Random Mistuning ◽  
Nature Frequency ◽  
Grouped Blades

Vibration localization of bladed disk turns to be much complex when a number of blades are assembled into periodic groups. This work focused on natural frequency distribution and modal localization of bladed disks with grouped blades based on the lumped parameter models, and effects of the blade number in each group on natural frequency were studied. Then Monte Carlo method was applied to analyze the sensitivity of modal localization to the random mistuning of blade stiffness. The results show that the number of blades in each group influences the nature frequency of bladed disk with grouped blades, and modal localization of tuned bladed disk with grouped blades is found in the closely spaced modal region. Moreover, compared to the bladed disk with free blades, the modal localization of bladed disk with grouped blades is much less sensitive to random mistuning of blade stiffness.

Vibration Response Characteristics of Bladed Disk With Continuous Ring Type Structure Losing Shroud and Stab

2010 ◽  
Author(s):  
Yasutomo Kaneko ◽  
Kazushi Mori ◽  
Hiroharu Ohyama
Keyword(s):  
Vibration Response ◽  
Type Structure ◽  
Analysis Method ◽  
Simple Analysis ◽  
Element Analysis ◽  
Disk Model ◽  
Continuous Ring ◽  
Ring Type ◽  
Response Characteristics ◽  
Bladed Disk

This paper presents a simple analysis method for predicting vibration response characteristics of a bladed disk with continuous ring type structure losing a shroud or a shroud and a stab between two blades. This loss introduces a mistuning of the system and the whole bladed disk model must be used to conduct the study. However, the vibration modes change regularly from a sine and a cosine mode, if the bladed disk consists of many blades. By utilizing this phenomenon, the simple formulation of vibration response of a bladed disk can be derived. Second, the parametric study on the vibration response characteristics of a bladed disk losing a shroud or a shroud and a stab is carried out extensively, utilizing the analysis method proposed here. From the calculated results, the vibration response characteristics of a bladed disk are clarified for both of resonant vibration and random vibration. Lastly, the results calculated by the simple analysis method proposed are compared with the results obtained from FEA (Finite Element Analysis) in order to verify the validity of the analysis method.

scholarly journals Vibration Response Characteristics of the Cross Tunnel Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Jinxing Lai ◽  
Kaiyun Wang ◽  
Junling Qiu ◽  
Fangyuan Niu ◽  
Junbao Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Vibration Response ◽  
Shield Tunnel ◽  
Tunnel Structure ◽  
Response Characteristics ◽  
Vehicle Load ◽  
Metro Tunnel

It is well known that the tunnel structure will lose its function under the long-term repeated function of the vibration effect. A prime example is the Xi’an cross tunnel structure (CTS) of Metro Line 2 and the Yongningmen tunnel, where the vibration response of the tunnel vehicle load and metro train load to the structure of shield tunnel was analyzed by applying the three-dimensional (3D) dynamic finite element model. The effect of the train running was simulated by applying the time-history curves of vibration force of the track induced by wheel axles, using the fitted formulas for vehicle and train vibration load. The characteristics and the spreading rules of vibration response of metro tunnel structure were researched from the perspectives of acceleration, velocity, displacement, and stress. It was found that vehicle load only affects the metro tunnel within 14 m from the centre, and the influence decreases gradually from vault to spandrel, haunch, and springing. The high-speed driving effect of the train can be divided into the close period, the rising period, the stable period, the declining period, and the leaving period. The stress at haunch should be carefully considered. The research results presented for this case study provide theoretical support for the safety of vibration response of Metro Line 2 structure.

Theoretical Study of the Vibration Suppression on a Mistuned Bladed Disk Using a Bi-periodic Piezoelectric Network

2018 ◽  
Vol 35 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Lin Li ◽  
Pengcheng Deng ◽  
Jiuzhou Liu ◽  
Chao Li
Keyword(s):  
Vibration Suppression ◽  
Robustness Analysis ◽  
Forced Response ◽  
Lumped Parameter Model ◽  
Modal Assurance Criterion ◽  
Vibration Localization ◽  
Bladed Disk ◽  
Lumped Parameter ◽  
Random Mistuning ◽  
Response Amplification

AbstractThe paper deals with the vibration suppression of a bladed disk with a piezoelectric network. The piezoelectric network has a different period (so called bi-period) from that of the bladed disk and there is no inductor in it. The system is simulated by an electromechanical lumped parameter model with two DOFs per sector. The research focuses on suppressing the amplitude magnification or reducing the vibration localization of the mistuned bladed disk. The dynamic equations of the system are derived. Both mechanical mistuning and electrical mistuning have been taken into account. The Modified Modal Assurance Criterion (MMAC) is used to evaluate the vibration suppression ability of the bi-periodic piezoelectric network. The Monte Carlo simulation is used to calculate the MMAC of the system with the random mistuning. As a reference, the forced responses of the bladed disk with and without the piezoelectric network are given. The results show that the piezoelectric network would effectively suppress amplitude magnification induced by mistuning. The vibration amplitude is even smaller than that of the tuned system. The robustness analysis shows that the bi-periodic piezoelectric network can provide a reliable assurance for avoiding the forced response amplification of the mistuned bladed disk. The amplified response induced by the mechanical mistuning with standard deviation 0.2 can be effectively suppressed through the bi-periodic piezoelectric network.

Intentional Mistuning Design Space Reduction Based on Vibration Energy Flow in Bladed Disks

2004 ◽  
Author(s):  
Sang-Ho Lim ◽  
Matthew P. Castanier ◽  
Christophe Pierre
Keyword(s):  
Energy Flow ◽  
Design Space ◽  
Flow Analysis ◽  
Design Guidelines ◽  
Vibration Energy ◽  
Bladed Disk ◽  
Space Reduction ◽  
Lumped Parameter ◽  
Lumped Parameter Models ◽  
Random Mistuning

Intentional mistuning is the deliberate incorporation of blade-to-blade parameter variations in the nominal design of a bladed disk. Previous studies have shown that this is a promising strategy for mitigating the damaging effects of unintended, random mistuning. In this paper, the mechanisms of intentional mistuning are studied by investigating the relation between blade response and vibration energy flow in lumped parameter models. Based on key observations from the energy flow analysis, a few design guidelines are proposed that drastically reduce the design space for intentional mistuning patterns. Thus, an optimization may be performed on the reduced design space or skipped altogether, yielding dramatic reductions in computational costs. The guidelines are validated by extensive Monte Carlo simulations for the lumped parameter models as well as for a finite-element-based reduced-order model of an industrial rotor. It is shown that the reduced design space includes optimal or near-optimal intentional mistuning patterns.

scholarly journals Modeling and parameter identification of seated human body with the reference vector guided evolutionary algorithm

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110626
Author(s):  
Shuguang Zhang ◽  
Wenku Shi ◽  
Zhiyong Chen
Keyword(s):  
Parameter Identification ◽  
Evolutionary Algorithm ◽  
Dynamic Model ◽  
Human Body ◽  
Ride Comfort ◽  
Vibration Response ◽  
Lumped Parameter Model ◽  
Reference Vector ◽  
Response Characteristics ◽  
Lumped Parameter

The low frequency vibration of the vehicle in motion has a great influence on the ride comfort of occupants. The research on the vibration response characteristics of human body plays a great role in analyzing and improving ride comfort. The purpose of this study was to investigate the parameter identification of seated human body dynamic model. A seven-degree-of-freedom (DOF) lumped parameter model was established to describe the vibration response characteristics of human body. The derivation processes of apparent mass (AM) and seat to head transmissibility (STHT) were performed. After the theoretical calculation of the human body vibration characteristics, we used several different evolutionary algorithms to identify the 23 parameters of the model, including the mass, stiffness and damping parameters. By comparing the results of the five optimization algorithms and comprehensively analyzing the convergence and distribution of the non-dominated solution set, we found that the reference vector guided evolutionary algorithm (RVEA) shows good competitiveness in solving many-objective optimization problem (MaOP), that is, parameter identification of seated human body model in this paper. The AM and STHT calculated by model identification were compared with their measured by experiment. The result shows that the selected seven-DOF model can well describe the vertical vibration characteristics of seated human body and the identification method used in this paper can accurately identify the parameters of lumped parameter model, which provides convenience for the establishment of a complete “road-vehicle-seat-human body” system dynamic model.

scholarly journals Study on vibration response characteristics of mistuned bladed disk (Mistuning phenomena evaluated by vibratory stress)

2016 ◽  
Vol 82 (837) ◽  
pp. 15-00537-15-00537
Author(s):  
Yasutomo KANEKO ◽  
Masamichi MIYAKE ◽  
Kazushi MORI ◽  
Hiroharu OOYAMA
Keyword(s):  
Vibration Response ◽  
Response Characteristics ◽  
Bladed Disk
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