scholarly journals A quick update method of coupled vibration responses for efficient evaluation of changed satellite structure

2020 ◽  
Vol 86 (892) ◽  
pp. 20-00379-20-00379
Author(s):  
Tomoya NIWA ◽  
Nobuyuki SHINOHARA ◽  
Qinzhong SHI
Keyword(s):  
Coupled Vibration ◽  
Satellite Structure ◽  
Vibration Responses

Roll-Yaw Coupled Vibration of the Rotor System With Breathing Crack and Unbalance Mass

2015 ◽  
Author(s):  
J. Zhao ◽  
H. A. DeSmidt ◽  
M. Peng ◽  
W. Yao
Keyword(s):  
Coupling Effect ◽  
Rotor System ◽  
Crack Model ◽  
Clear Understanding ◽  
Coupled Vibration ◽  
Breathing Crack ◽  
Energy Concept ◽  
Vibration Responses ◽  
Rolling Rate ◽  
Rotor Model

This paper develops a new finite element rotor model with consideration of the coupling effect of rolling and yawing motion. The crack model is built using released strain energy concept in fracture mechanics. The nonlinear breathing behavior of cracks on the rotor shaft is simulated through Zero Stress Intensity Factor (SIF) method. The vibration responses of rotor system are solved by Newmark Integration method for both nominal and damaged system. With the yawing motion, the additional force will be induced for beam element and center disk. Incorporated with breathing crack model, the breathing behavior of crack is comprehensively studied in terms of the rolling rate, yawing rate and yawing acceleration. The clear understanding of crack breathing behavior is beneficial for the damage detection and health monitoring of the rotor system.

scholarly journals Vehicle Ride Comfort Analysis Based on Vehicle-Bridge Coupled Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yichang Zhang ◽  
Wusheng Li ◽  
Zhe Ji ◽  
Guichun Wang
Keyword(s):  
Rational Design ◽  
Ride Comfort ◽  
Dynamic Balance ◽  
Dynamic Responses ◽  
Ride Quality ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Coupling Vibration ◽  
Multiple Vehicles ◽  
Vibration Responses

The study in this paper aims to evaluate the effects of vehicle-bridge coupled vibration on the vehicle ride comfort. The mechanical model of both vehicle and bridge subsystems and the vibration differential equations are established, respectively, based on the principle of dynamic balance and finite element method. The APDL command stream for iterative calculation is compiled on the ANSYS platform. The method to evaluate the vehicle ride comfort is established according to the criteria in ISO2631-1-1997. The vehicle dynamic responses and ride comfort are analyzed considering different pavement levels while multiple vehicles pass through the cable-stayed bridge. The analysis results indicate that the dynamic responses of vehicles decrease with the improvement of pavement roughness, resulting in the vehicle ride comfort to be better; the dynamic responses of vehicles increase with the increment of vehicle speed or the decrement of vehicle gravity, resulting in the vehicle ride comfort to be worse. The present research results can provide an insight into the rational design of bridge structure so as to reduce the vehicle-bridge coupling vibration responses and improve the ride quality of drivers and passengers.

An hourglass-type electromagnetic isolator with negative resistance electromagnetic shunt circuit

2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang
Keyword(s):  
Vibration Isolation ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Negative Resistance ◽  
Isolation System ◽  
Amplitude Vibration ◽  
Vibration Responses ◽  
The Stability ◽  
Isolation Performance ◽  
Shunt Circuit

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.

Coupled vibration model of cables and its parameter analysis

2015 ◽  
Vol 32 (3) ◽  
pp. 231
Author(s):  
Haitao Liu ◽  
Minghai Wei ◽  
Kun Lin ◽  
Yiqing Xiao
Keyword(s):  
Parameter Analysis ◽  
Coupled Vibration ◽  
Vibration Model

scholarly journals Spatially Resolved Experimental Modal Analysis on High-Speed Composite Rotors Using a Non-Contact, Non-Rotating Sensor

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Structural Dynamic ◽  
Spatially Resolved ◽  
Glass Fiber Reinforced ◽  
Vibration Responses ◽  
And Performance

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.

Analysis of vibration response and machining quality of hybrid robot based UD-CFRP trimming

2021 ◽  
pp. 095440542098609
Author(s):  
Yan Zhang ◽  
Hao Li ◽  
Xuda Qin ◽  
Jie liu ◽  
Zhuojie Hou
Keyword(s):  
High Performance ◽  
Vibration Response ◽  
Industrial Robots ◽  
Force Characteristic ◽  
Surface Waviness ◽  
Machined Surface ◽  
Machining Quality ◽  
3D Surface Roughness ◽  
Machined Surface Quality ◽  
Vibration Responses

To fulfill the demands of higher precision, better quality, and more flexibility, the usage of high-performance industrial robots is rapidly increased in aerospace industry. Considering the anisotropic and inhomogeneous characteristics of composite materials, this study focuses mainly on dynamic response investigation of a newly designed hybrid robot (named as TriMule) in CFRP trimming process and its influence on the machined quality. First, combined with the cutting force characteristic, the vibration responses of tool center point (TCP) under the dynamic excitation were obtained. The influences of robotic TCP vibration on machined surface quality with different fiber orientations, including surface waviness, cavity, 3D surface roughness, and depth of affected zone, are first studied by comparing hybrid robot and machine tool. From experiment results, it can be concluded the proposed TCP vibration response model has sufficient prediction accuracy. Meanwhile, it is found that larger robotic vibration response is accompanied by higher surface waviness, bigger surface cavity, and greater affected zone. Results also showed that the fiber orientation and milling style are two essential factors that affect robot vibration and machining quality during CFRP trimming.

scholarly journals Vibration responses of a satellite subjected to acoustic excitation at launch stage

2021 ◽  
Vol 1786 (1) ◽  
pp. 012034
Author(s):  
Jie Zhang ◽  
Weihua Xie ◽  
Jiacong Yin ◽  
liu Huiliang ◽  
Jiang Zhou
Keyword(s):  
Acoustic Excitation ◽  
Vibration Responses
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