scholarly journals Variable Volumetric Stiffness Fluid Mount Design

2004 ◽  
Vol 11 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Nader Vahdati ◽  
Mehdi Ahmadian
Keyword(s):  
Mathematical Model ◽  
Cycle Time ◽  
Manufacturing Process ◽  
Frequency Tuning ◽  
Track Length ◽  
Trial And Error ◽  
Optimum Location ◽  
Aerospace Applications ◽  
Model And Simulation ◽  
Simulation Results

Passive fluid mounts are commonly used in the automotive and aerospace applications to isolate the cabin from the engine noise and vibration. Due to manufacturing and material variabilities, no two identical fluid mount designs act the same. So, fluid mounts are tuned one by one before it is shipped out to customers. In some cases, for a batch of fluid mounts manufactured at the same time, one is tuned and the rest is set to the same settings. In some cases they are shipped as is with its notch frequency not being in its most optimum location. Since none of the passive fluid mount parameters are controllable, the only way to tune the mount is to redesign the mount by changing fluid, changing inertia track length or diameter, or changing rubber stiffness. This trial and error manufacturing process is very costly. To reduce the fluid mount notch frequency tuning cycle time, a new fluid mount design is proposed. In this new fluid mount design, the notch frequency can be easily modified without the need for any redesigns. In this paper, the new design concept, and its mathematical model and simulation results will be presented.

Single Pumper Semi-Active Fluid Mount

2003 ◽  
Author(s):  
Nader Vahdati ◽  
Mehdi Ahmadian
Keyword(s):  
Vibration Isolation ◽  
Frequency Tuning ◽  
Vibration Reduction ◽  
Track Length ◽  
Noise And Vibration ◽  
Aerospace Applications ◽  
Cabin Noise ◽  
Model And Simulation ◽  
The Right ◽  
Noise And Vibration Reduction

Passive fluid mounts have been in use in the automotive and aerospace applications for the purpose of cabin noise and vibration reduction since 1940s. Cabin noise and vibration isolation is provided at a frequency coined “notch frequency”. The design location of the notch frequency depends on the application, but with most applications, it is designed to coincide with the longest period of constant speed. To obtain greater cabin noise and vibration reduction at any desired frequency, the notch frequency needs to be as close to that desired frequency as possible. Unfortunately, due to tolerances on all the fluid mount dimensions, material property variations, and variation in elastomer molding processes, the notch frequency never ends up at the right location on the first manufacturing pass. Since none of the passive fluid mount parameters are controllable, the only way to tune the mount is to redesign the mount by changing fluid, changing inertia track length or diameter, or changing rubber stiffness. This trial and error manufacturing process is very costly. To reduce the fluid mount notch frequency tuning cycle time, a new fluid mount design is proposed. In this paper, the new design concept, and its mathematical model and simulation results will be presented.

Design of 2_DOF Simulation Platform for the Testing of Airborne Laser Communication APT System

2014 ◽  
Vol 989-994 ◽  
pp. 3683-3688
Author(s):  
Li Xin Meng ◽  
Ding Xuan Zhao ◽  
Yang Yang Bai ◽  
Li Zhong Zhang
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Closed Loop ◽  
Laser Communication ◽  
Motion Simulation ◽  
Vector Method ◽  
Kinematics Model ◽  
Airborne Laser ◽  
Model And Simulation ◽  
Simulation Results

Lightweight, flexible motion simulation is the demand of airborne laser communication optical transceive when apply to outside test. A new parallel 2_DOF platform that has the function of azimuth and pitching is put forword based on the analysis of airplane position-pose changes affect the performance airborne laster communication APT system, and the kinematics model is established by using closed-loop vector method. Kinematics model is right through the comparison of mathematical model and simulation results of ADAMS, which provides the reference and basis for the design of control system.

Computer Simulation of Controlled Hydraulic Impactor System

2011 ◽  
Vol 179-180 ◽  
pp. 122-127 ◽  
Author(s):  
Guo Ping Yang ◽  
Jun Hao Gao ◽  
Bo Chen
Keyword(s):  
Mathematical Model ◽  
Simulation Environment ◽  
Opening Pressure ◽  
Impact Performance ◽  
Model And Simulation ◽  
Working Principle ◽  
Simulation Results ◽  
Working Performance ◽  
New Generation ◽  
Pilot Valve

In view of general impactor whose parameters can’t be adjusted continually in different conditions, a kind of controlled hydraulic impactor is introduced. Its non-linear mathematical model and simulation model are established. In simulation environment, adjusting opening pressure of pilot valve, supply oil volume and charging pressure of accumulator respectively, influences on the working performance are investigated. Simulation results prove that, working principle of controlled hydraulic impactor is available and its impact performance is superior to traditional impactor. This provides theory basis for innovation and production of a new generation impactor.

Four Order ESD Generator Circuit Model and its Simulation

2012 ◽  
Vol 239-240 ◽  
pp. 264-269 ◽  
Author(s):  
Jin Shan Wang ◽  
Ke Wang ◽  
Xiao Dong Wang
Keyword(s):  
Mathematical Model ◽  
Circuit Model ◽  
Model Construction ◽  
Generator Circuit ◽  
Model And Simulation ◽  
Simulation Results ◽  
Testing Standards ◽  
The Mathematical Model

Basis international electrician committee issued IEC61000-4-2 testing standards, proposed a new ESD current expression. Using Laplasse transform, established the ESD system mathematical model, according to the mathematical model, construction of passive four order ESD system circuit model and active four order ESD system circuit model, and simulation. The simulation results meet the IEC61000-4-2 standard, and verify the ESD current expression, the mathematical model and the circuit model of consistency.

Model and Simulation for Driving System of Four-Wheel-Drive Electric Vehicle

2013 ◽  
Vol 336-338 ◽  
pp. 480-483
Author(s):  
Guo Kai Xu ◽  
Tao Zhang ◽  
Xiu Chun Zhao ◽  
Juan Wang
Keyword(s):  
Mathematical Model ◽  
Electric Vehicle ◽  
Pi Control ◽  
Driving System ◽  
Model And Simulation ◽  
Wheel Drive ◽  
Simulation Results ◽  
Four Wheel Drive ◽  
The Mathematical Model ◽  
Vehicle Movement

Model for drive system of four-wheel-drive electric vehicle was investigated. By combing the balance equation for the vehicle movement with the equation of motor mechanical properties, a mathematical model of driving system of electric vehicle was established, PI control strategy was used for the optimal control and the model was simulated by the software Matlab/Simulink. The simulation results show that the mathematical model of driving system of the electric vehicle can represent the vehicle running states accurately.

Design and research of signal-level airborne electronic reconnaissance simulation system

2018 ◽  
Vol 09 (04) ◽  
pp. 1850030 ◽  
Author(s):  
Yang Zhao ◽  
Chaoxuan Shang ◽  
Zhuangzhi Han
Keyword(s):  
Mathematical Model ◽  
Euclidean Distance ◽  
Simulation System ◽  
Test Results ◽  
Simulation Test ◽  
New Thought ◽  
Model And Simulation ◽  
Electronic Countermeasure ◽  
Simulation Results ◽  
Good For

Airborne passive electronic reconnaissance equipment has developed rapidly during recent years. However, because of its expensive and unavailable military features, the simulation realization of these equipment needs to be solved. And the smaller the simulation particle is, the better the simulation system will be. In this study, a signal-level airborne electronic reconnaissance simulation system was built. Mathematical model and simulation realization of each part are introduced in this study. Focusing on the shortness of traditional signal sorting methods, we creatively proposed a presorting method based on the Euclidean distance inside signal flows. Simulation results show that the presorting method based on Euclidean distance successfully reduced the pressure on main sorting and appeared good for signal sorting. Simulation test results of each model built in this study are also shown in the study. This study provides a new thought on the realization of airborne electronic reconnaissance equipment and benefits the development of electronic countermeasure.

scholarly journals Dynamics of Rubber Band Stretch Ejection

2021 ◽  
Author(s):  
Xiang Li ◽  
Bohua Sun ◽  
Yi Zhang ◽  
Yuanfan Dai
Keyword(s):  
Mathematical Model ◽  
Rubber Band ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Finite Element Software ◽  
Model And Simulation ◽  
Elastic Rebound ◽  
Simulation Results ◽  
The Mathematical Model ◽  
The Relationship

Why do stretched rubber bands not hit the hand after ejection? What is the mechanism behind the rubber band ejection dynamics? These questions represent a fascinating scientific problem. Because the size of a rubber band in the circumferential direction is much larger than that in the other two directions of its cross-section, we regard the rubber band as a slender beam and establish a mathematical model of the dynamics of the rubber band stretching and ejection. Furthermore, we obtain the dependence of the dynamic curvature of the rubber band on the arc length and time. We used the finite element software ABAQUS to simulate the dynamic process of a rubber band stretching and ejection. The simulation results and dimensional analysis were performed to examine the effect of the bending elastic rebound velocity. The mathematical model and simulation results revealed that the relationship between the curvature and time at the end of the rubber band ($s =0$) was as follows: $\kappa\sim t^{-{1}/{2}}$. This research has guiding significance for the design of rubber bands as elastic energy storage devices.

scholarly journals Dynamics of Rubber Band Stretch Ejection

2021 ◽  
Author(s):  
Xiang Li ◽  
Bohua Sun ◽  
Yi Zhang ◽  
yuanfan Dai
Keyword(s):  
Mathematical Model ◽  
Rubber Band ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Finite Element Software ◽  
Model And Simulation ◽  
Elastic Rebound ◽  
Simulation Results ◽  
The Mathematical Model ◽  
The Relationship

Abstract Why do stretched rubber bands not hit the hand after ejection? What is the mechanism behind the rubber band ejection dynamics? These questions represent a fascinating scientific problem. Because the size of a rubber band in the circumferential direction is much larger than that in the other two directions of its cross section, we regard the rubber band as a slender beam and establish a mathematical model of the dynamics of the rubber band stretching and ejection. Furthermore, we obtain the dependence of the dynamic curvature of the rubber band on the arc length and time. We used the finite element software ABAQUS to simulate the dynamic process of rubber band stretching and ejection. The simulation results and dimensional analysis were performed to examine the effect of the bending elastic rebound velocity. The mathematical model and simulation results revealed that the relationship between the curvature and time at the end of the rubber band ($s =0$) was as follows: $\kappa\sim t^{-{1}/{2}}$. This research has guiding significance for the design of rubber bands as elastic energy storage devices.

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