Influences of Diaphragm Springs on Operation Performances of Sight-Stabilizing Mechanism

2011 ◽  
Vol 211-212 ◽  
pp. 384-388
Author(s):  
Gui Mei Guo ◽  
Lin Hong
Keyword(s):  
Rigid Body ◽  
Structural Parameters ◽  
Angular Displacement ◽  
Kinematics And Dynamics ◽  
Analysis Method ◽  
Structure Form ◽  
Simulation Results ◽  
Fix Point ◽  
The Moment

Sight-stabilizing mechanisms controlled by diaphragm springs and other damping elements is an important subordinate system of airborne sight stabilizing System. The performances of sight-stabilizing system depend on the characteristics of kinematics and dynamics of the system in a great extent. Among various external moments acting on the rod of the manipulator, such as those moments caused by damper, positioning spring, and restoration spring, the forces by diaphragm springs are most obvious. According to the structure form and motion peculiarity, the rod can be equivalent to a rigid body turning around a fix point. Simulation results reveal that the moment of the restoration spring to the rod is proportional to the angular displacement, and that the moment is the most prominent factor influencing the operating performances among all these moments. Through reasonable adjustments of structural parameters of the restoration spring, the performances of the sight-stabilizing system can be improved greatly; the analysis method provides a basis for guiding the design of concerned structural parameters of sight-stabilizing system.

Rigid-compliant hybrid variation analysis using Monte Carlo interval approach for low-rigidity aircraft structure assembly

2021 ◽  
Author(s):  
Biao Mei ◽  
Haijin Wang
Keyword(s):  
Monte Carlo ◽  
Rigid Body ◽  
Structural Parameters ◽  
Production Volume ◽  
Geometric Errors ◽  
Analysis Method ◽  
Variation Analysis ◽  
Aircraft Structure ◽  
Aircraft Manufacturing ◽  
Interval Approach

Abstract To reduce downstream rework and design changes, variation modeling and analysis are indispensable in the assembly of complex products. In this paper, a rigid-compliant hybrid variation analysis method using the Monte Carlo interval approach is developed to assembly ladder structures, such as the skeleton of a horizontal stabilizer or a wing box. We first present the classical locating scheme of a low-rigidity aeronautical structure, and the contributors to the assembly variation of a ladder structure comprising locating errors and part geometric errors. Assembly variations induced by rigid-body locating errors and part geometric errors are mathematically modeled with rigid-body kinematics and the mechanistic method based on the Finite Element Analysis, respectively. And then, the two types of assembly variations are integrated into a rigid-compliant hybrid variation model. Probability distributions of the contributors are often unknown, especially in aircraft manufacturing with low production volume. Therefore, a novel variation analysis method using the Monte Carlo interval approach is proposed to compute the assembly variation, represented in the form of interval structural parameters. The assembly case of a scale wing skeleton shows the proposed rigid-compliant hybrid variation analysis method is efficient in the assembly variation analysis for low-rigidity aircraft structure.

The Dynamic Simulation of Engine Slider-Crank Mechanism Based on ANSYS and ADAMS

2013 ◽  
Vol 842 ◽  
pp. 347-350 ◽  
Author(s):  
Li Ni ◽  
Ya Yu Huang ◽  
Chong Kai Zhou
Keyword(s):  
Rigid Body ◽  
Dynamic Simulation ◽  
Simulation Analysis ◽  
Coupled Model ◽  
Dynamics Simulation ◽  
Kinematics And Dynamics ◽  
Kinematics Simulation ◽  
Bias Model ◽  
Simulation Results ◽  
Crank Mechanism

Establishing bias and central entity model of slider-crank mechanism in this paper, then the bias model is imported into the ADAMS for kinematics simulation, and we can get the sliders law of motion. Then using ANSYS and ADAMS jointly to establish the multiple rigid body and the coupled model of slider-crank mechanism, and carrying on kinematics and dynamics simulation analysis to compare the two simulation results. Through build simulation of the coupled model with UG, ANSYS and ADAMS, the result of this calculation is better to reflect the true movement of the mechanism.

Transfers with a rendezvous lasting no more than one orbit between close near-circular coplanar orbits

2020 ◽  
pp. 82-93
Author(s):  
Aleksandr F. BRAGAZIN ◽  
Alexey V. USKOV
Keyword(s):  
Key Words ◽  
Relative Velocity ◽  
Free Parameter ◽  
Space Station ◽  
Characteristic Velocity ◽  
Orbital Station ◽  
Orbit Transfer ◽  
Simulation Results ◽  
The Moment ◽  
Phase Differences

Consideration has been given to orbit transfers involving spacecraft rendezvous which belong to a class of coplanar non-intersecting near-circular orbits of a spacecraft and a space station. The duration of the transfer is assumed to be limited by one orbit. The feasibility of a rendezvous using an optimal two-burn orbit-to-orbit transfer is studied. To determine a single free parameter of the transfer, i.e. the time of its start, ensuring a rendezvous at a given time or at a given velocity at the end of transfer, appropriate equations have been obtained To implement in the guidance algorithms optimal three-burn correction programs are proposed to achieve a rendezvous at a given time with a specified relative velocity at the moment of spacecraft contact. A range of phase differences at the start of maneuvering is determined, within which the characteristic velocity of the rendezvous is equal to the minimum characteristic velocity of the orbit-to-orbit transfer. The paper presents simulation results for “quick" rendezvous profiles that use the proposed programs. Key words: spacecraft, orbital station, “quick” rendezvous, orbit transfer, rendezvous program.

Dual-Hop Amplify-and-Forward Variable Gain Relaying over Mixture Gamma Fading Channels

2015 ◽  
Vol 719-720 ◽  
pp. 767-772
Author(s):  
Wei Jun Cheng
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Symbol Error Rate ◽  
Amplify And Forward ◽  
Variable Gain ◽  
Average Symbol Error Rate ◽  
Simulation Results ◽  
End To End ◽  
The Moment ◽  
Relaying System

In this paper, we present the end-to-end performance of a dual-hop amplify-and-forward variablegain relaying system over Mixture Gamma distribution. Novel closed-form expressions for the probability density function and the moment-generation function of the end-to-end Signal-to-noise ratio (SNR) are derived. Moreover, the average symbol error rate, the average SNR and the average capacity are found based on the above new expressions, respectively. These expressions are more simple and accuracy than the previous ones obtained by using generalized-K (KG) distribution. Finally, numerical and simulation results are shown to verify the accuracy of the analytical results.

Study on Engine Kinematics and Dynamics Simulation Based on COSMOSMotion

2012 ◽  
Vol 503-504 ◽  
pp. 731-734
Author(s):  
Xiao Xu Liu ◽  
Min Chen ◽  
Ai Hua Tang
Keyword(s):  
Virtual Prototype ◽  
Dynamics Simulation ◽  
Kinematics And Dynamics ◽  
Engine Model ◽  
Kinematics Simulation ◽  
Simulation Based ◽  
Calculation Results ◽  
Simulation Results ◽  
Dynamics Simulations

The engine model with 4 cylinders is built by SolidWorks, the kinematics and dynamics simulations of the engine virtual prototype are done by COSMOSMotion, the results of kinematics simulation are checked, there are very small errors between the simulation results and the calculation results according to formulas. The mainly results of dynamics simulation are given. The simulation result consists with the parameters of the engine.

A Bandgap Reference with Temperature Coefficient of 13.2 ppm/°C

2014 ◽  
Vol 981 ◽  
pp. 66-69
Author(s):  
Ming Yuan Ren ◽  
En Ming Zhao
Keyword(s):  
Power Supply ◽  
Process Simulation ◽  
Output Voltage ◽  
Operating Temperature ◽  
Cmos Process ◽  
Bandgap Reference ◽  
Analysis Method ◽  
Operation Condition ◽  
Reference Circuit ◽  
Simulation Results

This paper presents a design and analysis method of a bandgap reference circuit. The Bandgap design is realized through the 0.18um CMOS process. Simulation results show that the bandgap circuit outputs 1.239V in the typical operation condition. The variance rate of output voltage is 0.016mV/°C? with the operating temperature varying from-60°C? to 160°C?. And it is 3.27mV/V with the power supply changes from 1.8V to 3.3V.

Motion Simulation of Key Components in a Package Machine

2012 ◽  
Vol 557-559 ◽  
pp. 2303-2306
Author(s):  
Shu Bin Kan
Keyword(s):  
Structural Parameters ◽  
Center Of Mass ◽  
Motion Simulation ◽  
Software Environment ◽  
Optimization Result ◽  
Adams Software ◽  
Motion Characteristic ◽  
The Moment ◽  
Selection Of

The motion characteristic of key components is a decisional factor to the working reliability and stability of a package machine. In this paper, the motion simulation of a key component is carried out in the ADAMS software environment. By analysis of the force, variance of the center-of-mass and the moment of the component, the mutation point in the motion is found, and then the structure is optimized by selection of different structural parameters. The optimization result shows a significant improvement for the reliability and stability of the whole machine.

Study on the Thermo-Hydrodynamic of a Dry Gas Seal in Helium Circulator for High Temperature Gas-Cooled Reactor

2011 ◽  
Author(s):  
Jianshu Lin ◽  
Hong Wang
Keyword(s):  
High Temperature ◽  
Film Flow ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Analysis Method ◽  
Dry Gas Seal ◽  
Safety Requirements ◽  
Simulation Results ◽  
Gas Seals ◽  
High Temperature Gas

A comprehensive analysis method is proposed to resolve the problem of simulating a complex thermo-flow with two kinds of distinct characteristic length in the dry gas seal, and a conjugated simulation of the complicated heat transfer and the gas film flow is carried out by using the commercial CFD software CFX. By using the proposed method, a three dimensional of velocity and pressure field in the gas film flow and the temperature distribution within the sealing rings are investigated for three kinds of film thickness, respectively. A comparison of thermo-hydrodynamics of the dry gas seals is conducted between the sealed gas of air and helium. The latter one is used in a helium circulator for High Temperature Gas-cooled Reactor (HTGR). From comparisons and discussions of a series of simulation results, it will be found that the comprehensive proposal is effective and simulation results are reasonable, and the maximum temperature rise in the dry gas seal is within the acceptable range of HTGR safety requirements.

Finding Principal Axes of Complex Plane Rigid Body with Rending-Image of MATLAB

2012 ◽  
Vol 490-495 ◽  
pp. 2156-2159
Author(s):  
Wu Gang Li
Keyword(s):  
Rigid Body ◽  
Complex Plane ◽  
Principal Axis ◽  
Flat Surface ◽  
Moment Of Inertia ◽  
Principal Axes ◽  
The Moment

In order to find the principal axes of inertia and calculate their moment of inertia to any plane homogeneous rigid body for calculating easily the moment of inertia to any axis of this rigid body, the principal axes could be found and their moment of inertia could be calculated automatically by using the reading-image of MATLAB to read the image messages about the flat surface of the rigid body and by the procedures which ware made according to the logic relation about the principal axis and the moment of inertia of the rigid body. Applying this method in a homogeneous cube, a result was acquired, error of which is small compared with the theoretical value. So this method is reliable, convenient and practical

scholarly journals Rolling of a rigid body without slipping and spinning: kinematics and dynamics

2012 ◽  
pp. 783-797 ◽  
Author(s):  
A. V. Borisov ◽  
◽  
I. S. Mamaev ◽  
D. V. Treschev ◽  
◽  
...  
Keyword(s):  
Rigid Body ◽  
Kinematics And Dynamics
Sign in / Sign up

Export Citation Format

Share Document