scholarly journals Research on Transfer Characteristics of Engine Vibration Load to Cabin Seat

2020 ◽  
Vol 38 (6) ◽  
pp. 1163-1170
Author(s):  
Juncheng Shu ◽  
Erming He ◽  
Jinxiang Yi ◽  
Pengxiang Chen
Keyword(s):  
Vibration Isolation ◽  
Vertical Direction ◽  
Frequency Component ◽  
Vertical Acceleration ◽  
Load Spectrum ◽  
Contribution Rate ◽  
Vibration Transmission ◽  
Vibration Load ◽  
Engine Vibration ◽  
Double Beam

Aeroengine is one of the main vibration sources that affect the passenger comfort. The contribution of engine vibration to the vibration response of seat will provide basic data for the design of airliner vibration comfort and engine vibration isolation installation. Firstly, the dynamical model of middle fuselage compartment with double-beam wing was established. Then, based on the typical vibration load spectrum of the engine, the acceleration responses of the key nodes of the wing beam and the seat connection points were analyzed, and the main path of engine vibration transmission to seats was identified. Finally, using operational transfer path analysis (OTPA) method, the contribution of engine front and rear mount point vibration to the vertical acceleration response of the seats was compared, and the three-dimensional information of wing structure vibration transmission was explored. The results show that the fundamental frequency component of low-pressure rotor of engine vibration has the greatest impact on the seat vertical response under takeoff and cruise conditions, the contribution rate of the front mount point vibration is about 71% and 67% respectively. However, the fundamental and its 3/2 times frequency components of high-pressure rotor have relatively large impact on the seats vertical response under flight idle state, and the contribution rate of engine front mount point vibration is about 45% and 60% respectively. In addition, the engine vibration is mainly transmitted from the wing front beam to the seat vertical response. The vertical direction of the wing beam and the rotation direction around the fuselage are also the main direction of vibration transmission.

scholarly journals Research on dynamic characteristics of plate under pedestrian excitation based on Newmark-β

2018 ◽  
Vol 37 (4) ◽  
pp. 682-699
Author(s):  
Xinfang Ge ◽  
Weirong Wang ◽  
Wei Yuan
Keyword(s):  
Rectangular Plate ◽  
Dynamic Characteristics ◽  
Vibration Isolation ◽  
Great Influence ◽  
Interaction Model ◽  
Vertical Direction ◽  
Structural Vibration ◽  
Normal Walking ◽  
Plate Structure ◽  
Pedestrian Excitation

Development of micro and ultra-precision machining, precision instruments and equipment, precision assembly and testing has put forward more and more high requirements to vibration isolation on environmental elements, especially the pedestrian excitation generated by workers' normal walking. Therefore, it is very important to study the pedestrian excitation's influence on vibration characteristics of precision instruments and equipment. In this study, dynamic model including mathematical model of pedestrian excitation, interaction model between pedestrian and rectangular plate structure, the human–plate coupled dynamic equation in vertical direction of pedestrian–plate structure was established. And then we use the Newmark-β method to solve the time-domain step-by-step integration of the first four order modes' dynamic equations and study the influence of the linear notion trajectory along the central axis direction on the dynamic characteristics of the rectangular plate. By simulation, we discussed plate structure response under different conditions, including plate structure displacement and acceleration response under the single person excitation with different velocities, under normal walking velocity with different number of pedestrians and under this case of different distance between two pedestrians. The results show that the structural vibration induced by pedestrian excitation has great influence on dynamic characteristics of plate.

scholarly journals Road Vehicle-Bridge Interaction considering Varied Vehicle Speed Based on Convenient Combination of Simulink and ANSYS

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Helu Yu ◽  
Bin Wang ◽  
Yongle Li ◽  
Yankun Zhang ◽  
Wei Zhang
Keyword(s):  
Reaction Force ◽  
Sudden Change ◽  
Vertical Direction ◽  
Dynamic Responses ◽  
Force Model ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Road Vehicle ◽  
The Road ◽  
Bridge Model

In order to cover the complexity of coding and extend the generality on the road vehicle-bridge iteration, a process to solve vehicle-bridge interaction considering varied vehicle speed based on a convenient combination of Matlab Simulink and ANSYS is presented. In this way, the road vehicle is modeled in state space and the corresponding motion equations are solved using Simulink. The finite element model for the bridge is established and solved using ANSYS. The so-called inter-history iteration method is adopted to realize the interaction between the vehicle model and the bridge model. Different from typical method of road vehicle-bridge interaction in the vertical direction, a detailed longitudinal force model is set up to take into account the effects of varied vehicle speed. In the force model, acceleration and braking of the road vehicle are treated differently according to their mechanical nature. In the case studies based on a simply supported beam, the dynamic performance of the road vehicle and the bridge under varied vehicle speeds is calculated and discussed. The vertical acceleration characteristics of the midpoint of beam under varied vehicle speed can be grouped into two periods. The first one is affected by the load transform between the wheels, and the other one depends on the speed amplitude. Sudden change of the vertical acceleration of the beam and the longitudinal reaction force are observed as the wheels move on or off the bridge, and the bridge performs different dynamic responses during acceleration and braking.

Application of Active Mount Engine Vibration Isolation to Fuzzy Control Systems

2013 ◽  
Vol 341-342 ◽  
pp. 1023-1027
Author(s):  
Hui Guo ◽  
Guo Chun Sun ◽  
Min Fan
Keyword(s):  
Control Systems ◽  
Pid Control ◽  
Vibration Isolation ◽  
The Body ◽  
Fuzzy Pid Control ◽  
Power Train ◽  
Engine Vibration ◽  
Control Scheme ◽  
Self Tuning ◽  
Piezoelectric Stack Actuator

An automobile power-train active mount system with a piezoelectric stack actuator is introduced. The influence caused by power-train to the body of the car is analyzed by means of parameter self-tuning fuzzy PID control, on which the simulating results are based. It turns out that this control scheme can restrain the influence better caused by power-train to the body of the car.

The Simulation and Optimization Design of Adams-Based Engine Suspension System

2014 ◽  
Vol 686 ◽  
pp. 529-534
Author(s):  
Jian Xin Xie ◽  
Xiao Le Wang ◽  
Chao Liu
Keyword(s):  
Initial Data ◽  
Optimization Design ◽  
Vibration Isolation ◽  
Design Method ◽  
Suspension System ◽  
Multi Objective Optimization ◽  
Intrinsic Frequency ◽  
Simulation And Optimization ◽  
Engine Vibration ◽  
Simulation Results

In this study, the engine suspension system was optimized for making the vibration between engine and car body minimized, and also the optimization was simulated using software Adams. The purpose of this study was to research the vibration isolation of the engine mounting system and implement multi-objective optimization for the intrinsic frequency. In this paper, the optimization was implemented in two ways: (1) the intrinsic frequency was optimized by reasonably allocating it: (2) the intrinsic frequency was optimized using energy decoupling. The optimized intrinsic frequencies were simulated using software Adams and then the simulation results were compared. The simulation results showed that the optimized energy distribution was almost up to 90% and the decoupling degree was greatly improved by comparing the initial data, proving the optimized data played a greater effect on engine vibration isolation and further verifying the feasibility of optimization design method.

An Observer-Based Active Vibration Isolation System Using the Voice-Coil Actuator

2013 ◽  
Vol 846-847 ◽  
pp. 161-166 ◽  
Author(s):  
Wei Chao Chi ◽  
Deng Qing Cao ◽  
Wen Hu Huang
Keyword(s):  
Vibration Isolation ◽  
Output Feedback Control ◽  
Vertical Direction ◽  
Voice Coil Motor ◽  
Working Environment ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Active Vibration ◽  
The Voice ◽  
Voice Coil Actuator

This paper focuses on an active vibration isolator based on voice-coil motor (VCM). The isolator may reduce the vibration in the range from 5 to 100Hz in one DOF which can provide the payloads on a satellite a more stable working environment. A VCM is designed and optimized to provide enough feedback force; the state-space model is established according to the basic governing equations of the VCM. The LQR controller based on a reduced-order observer is designed for an output feedback control system. The vibration isolation system is verified by numerical simulations and experiments in which the VCM is installed between the payload and the excitation bottom, with an accelerometer located on the payload in the vertical direction. Both the simulation and experiment results show that the vibration of the payload is reduced effectively using the voice-coil actuator designed here.

Active Control for Power-Train Vibration of Automotive Using Active Mounts

2013 ◽  
Vol 330 ◽  
pp. 598-601
Author(s):  
Guo Chun Sun ◽  
Li Meng He
Keyword(s):  
Optimal Control ◽  
Vibration Isolation ◽  
Linear Quadratic Regulator ◽  
Active System ◽  
Linear Quadratic ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Engine Vibration ◽  
Active Vibration ◽  
Piezoelectric Stack Actuator

In this work, a new active mount featuring piezostack actuators and a rubber element is proposed and applied to a vibration control system. After describing the configuration and operating principle of the proposed mount, an appropriate rubber element and appropriate piezostacks are designed. Through the analysis of the property of the rubber and piezoelectric stack actuator, a mechanical model of the active vibration isolation system with the active mounts is established. An optimal control algorithm is presented for engine vibration isolation system. the controller is designed according to linear quadratic regulator (LQR) theory. Simulation shows the active system has a better consequence in reducing the vibration of the chassis significantly with respect to the ACM and the optimal control than that in the passive system.

scholarly journals Dynamic Analysis of Vehicle Track Coupling Based on Double Beam Track Model

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yayun Qi ◽  
Huanyun Dai ◽  
Jianjin Yang ◽  
Kun Xu
Keyword(s):  
Frequency Band ◽  
High Frequency ◽  
Harmonic Excitation ◽  
Vertical Acceleration ◽  
Beam Model ◽  
Vertical Force ◽  
Nonlinear Method ◽  
Single Beam ◽  
Double Beam ◽  
Random Irregularity

The rail was considered as double Timoshenko beam in this paper, applied to the vehicle track coupling dynamics model; the Hertz nonlinear method is used to calculate the wheel rail contact force. Wheel rail vertical force and response of vehicle are calculated by using the model under random irregularity and single harmonic excitation; at the same time, wheel rail force and vertical acceleration response of 3-order, 10-order, and 19-order wheel polygon were calculated. The results show that, under the excitation of random irregularity, the wheel rail vertical force of two models was very close in the low frequency band, and the response of the double beam model in the high frequency band of 200–1000 Hz is larger than the single beam model, and the acceleration and displacement responses of the double beam model are relatively close. Under a single harmonic excitation, the double beam model has a shorter wheel rail force attenuation time than that of the single beam model. And wheel rail force peak value of double beam model is 9% larger than that of single beam model. Similarly, the vertical displacement of the double beam model increased by 2.6%. Under the 3-order and 10-order wheel polygon excitation, vertical wheel rail peak force of double beam is, respectively, 37.5% and 50% larger than single beam model; the vertical frame acceleration amplitude is 1 g and 1.7 g; under the 19-order polygon wheel excitation, the difference of the wheel rail force between two models is very small, and the amplitude of acceleration of bogie is 2.3 g. And double beam model has more advantage in analyzing high frequency problems such as wheel polygonization.

Mechanisms of Noise Transmission through Helicopter Gearbox Support Struts

1994 ◽  
Vol 116 (4) ◽  
pp. 548-554 ◽  
Author(s):  
M. J. Brennan ◽  
R. J. Pinnington ◽  
S. J. Elliott
Keyword(s):  
High Frequency ◽  
Vibration Isolation ◽  
Low Frequency ◽  
Structural Members ◽  
Vibration Transmission ◽  
Gear Noise ◽  
High Frequencies ◽  
Passive Vibration Isolation ◽  
In Series ◽  
Frequency Behavior

Helicopter gearbox support struts are structural members designed to take large compressive and tensile mechanical loads. They also act as vibration transmission paths connecting the major noise and vibration generators of the main rotor and gearbox to the fuselage and cabin. In this paper the mechanisms of vibration transmission through these struts are examined. The differences between the low frequency behavior that is important in the transmission of the rotor vibrations, and the high frequency behavior that is important in the transmission of gear noise are discussed. A flexible element is introduced in series with the strut, and the limitations of this simple passive measure in attenuating longitudinal and flexural vibrations are highlighted. The analysis shows that there is a difference in the mechanisms of vibration transmission between low and high frequencies, and that there are difficulties in applying effective passive vibration isolation measures to this system.

Sign in / Sign up

Export Citation Format

Share Document