Parametric Research on Micro-Zigzag Slot Mechanism in OICW

2011 ◽  
Vol 483 ◽  
pp. 699-704 ◽  
Author(s):  
Chuan Qin Liu ◽  
Wen Zhong Lou ◽  
Long Fei Zhang ◽  
Yong Jia Lv
Keyword(s):  
Mathematic Model ◽  
Rectangular Pulse ◽  
Structural Parameter ◽  
Delayed Effect ◽  
Linear Dynamic ◽  
Simulation Results ◽  
Motion Characteristics ◽  
Acceleration Signals ◽  
Theoretical Results ◽  
Simulation Condition

This paper describes the delayed effect on the motion characteristics of the slider in the S&A mechanism resulting from the micro-zigzag slot used in OICW (Objective Individual Combat Weapon) and studies its influence on the ability of filtering transient acceleration signals. Firstly, we established the mathematic model of the slider when the S&A mechanism was loaded by the rectangular pulse acceleration according to the Rigid Dynamic Mechanics Theory and got its analytical solution by using MATLAB. Secondly, to verify the feasibility of this micro-zigzag slot mechanism, we adopted two different kinds of acceleration loading curves, after the non-linear dynamic mechanics simulation on it by using ANSYS/LS-DYNA, displacement and velocity curves of the slider were calculated. Then, to find which structural parameter playing more important role in affecting the characteristics of micro-zigzag slot, we adopted Single-variable Method to study its structural parameter under the same simulation condition. The simulation results we got were almost consistent with the theoretical results. The parametric research of the micro-zigzag slot lays certain a foundation on the research of MEMS system.

scholarly journals Modeling and Kinematics Simulation of a Mecanum Wheel Platform in RecurDyn

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yunwang Li ◽  
Sumei Dai ◽  
Yuwei Zheng ◽  
Feng Tian ◽  
Xucong Yan
Keyword(s):  
Virtual Prototype ◽  
Mobile System ◽  
Design Quality ◽  
Simulation Experiments ◽  
Motion Models ◽  
Kinematics Simulation ◽  
Simulation Results ◽  
Mecanum Wheel ◽  
Motion Characteristics ◽  
Theoretical Results

The innovative method of modeling and kinematics simulation in RecurDyn are proposed, taking a Mecanum wheel platform(MWP) for omnidirectional wheelchair as research object. In order to study the motion characteristics and mobile performance of the MWP, the virtual prototype simulation model is established in SolidWorks, and virtual prototype simulation is carried out in RecurDyn. The experience of simulation for the MWP in RecurDyn is introduced, and the simulation steps and points for attention are described detailedly. The working states of the mobile system in real environment have been simulated through virtual simulation experiments. Four typical motion models including moving forward, moving laterally, moving laterally in the direction of 45°, and rotation have been simulated in RecurDyn. The simulation results exactly reflect the motion of the MWP. By comparing the simulation results with the theoretical results, there are acceptable errors that are relatively less overall in the simulation results. The simulation results can be used to predict the performance of the platform and evaluate the design rationality, and design quality can be improved according to the exposed problem. This paper can provide reference for the simulation of mobile platform by using RecurDyn.

scholarly journals A Convergent Collocation Approach for Generalized Fractional Integro-Differential Equations Using Jacobi Poly-Fractonomials

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 979
Author(s):  
Sandeep Kumar ◽  
Rajesh K. Pandey ◽  
H. M. Srivastava ◽  
G. N. Singh
Keyword(s):  
Differential Equation ◽  
Fractional Derivative ◽  
Collocation Method ◽  
Caputo Fractional Derivative ◽  
Fractional Derivatives ◽  
Special Cases ◽  
Collocation Approach ◽  
Linear And Nonlinear ◽  
Simulation Results ◽  
Theoretical Results

In this paper, we present a convergent collocation method with which to find the numerical solution of a generalized fractional integro-differential equation (GFIDE). The presented approach is based on the collocation method using Jacobi poly-fractonomials. The GFIDE is defined in terms of the B-operator introduced recently, and it reduces to Caputo fractional derivative and other fractional derivatives in special cases. The convergence and error analysis of the proposed method are also established. Linear and nonlinear cases of the considered GFIDEs are numerically solved and simulation results are presented to validate the theoretical results.

scholarly journals Microstructure Dependence of Effective Thermal Conductivity of EB-PVD TBCs

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1838
Author(s):  
Shi-Yi Qiu ◽  
Chen-Wu Wu ◽  
Chen-Guang Huang ◽  
Yue Ma ◽  
Hong-Bo Guo
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Stress ◽  
Effective Thermal Conductivity ◽  
Thermal Insulation ◽  
Inclination Angle ◽  
Physical Vapor Deposition ◽  
Thermal Contact ◽  
Mathematic Model ◽  
Columnar Structure ◽  
Structural Parameter

Microstructure dependence of effective thermal conductivity of the coating was investigated to optimize the thermal insulation of columnar structure electron beam physical vapor deposition (EB-PVD coating), considering constraints by mechanical stress. First, a three-dimensional finite element model of multiple columnar structure was established to involve thermal contact resistance across the interfaces between the adjacent columnar structures. Then, the mathematical formula of each structural parameter was derived to demonstrate the numerical outcome and predict the effective thermal conductivity. After that, the heat conduction characteristics of the columnar structured coating was analyzed to reveal the dependence of the effective thermal conductivity of the thermal barrier coatings (TBCs) on its microstructure characteristics, including the column diameter, the thickness of coating, the ratio of the height of fine column to coarse column and the inclination angle of columns. Finally, the influence of each microstructural parameter on the mechanical stress of the TBCs was studied by a mathematic model, and the optimization of the inclination angle was proposed, considering the thermal insulation and mechanical stress of the coating.

Modeling of Aluminum Extrusion Process Using Non-Orthogonal Block Structured Grids Based FVM

2011 ◽  
Vol 189-193 ◽  
pp. 1749-1752
Author(s):  
Rui Wang ◽  
Hong Zhong Li
Keyword(s):  
Mathematic Model ◽  
Extrusion Process ◽  
Special Treatment ◽  
Aluminum Extrusion ◽  
Rigid Plastic ◽  
Structured Grids ◽  
Simulation Results ◽  
Flow Theories ◽  
Volume Method ◽  
Die Extrusion

The mathematic model of 3D aluminum extrusion processes using finite volume method (FVM) was established in this paper. The basic theories and rigid-plastic flow theories of this model were researched and built. Non-orthogonal structured grids were used to match complex geometric boundaries and local refinement of grids was also realized. The collocated arrangement is used to discretize the governing equations on non-orthogonal grids directly, pressure oscillations bring by this arrangement and error caused by grid’s non-orthogonality is eliminated by special treatment. A pocket die extrusion process was simulated using the program developed in this paper. The simulation results were also compared with that simulated by FEM software Deform in the same process, material and die conditions. The feasibility and efficiency of the mathematic model built in this paper was demonstrated by the simulation results and the comparison.

Modeling and Testing of Linear Electric Servo System

2012 ◽  
Vol 241-244 ◽  
pp. 1411-1417
Author(s):  
Xue Jiao Zhao ◽  
Fan Lin
Keyword(s):  
Data Collection ◽  
Data Processing ◽  
Servo System ◽  
Mathematic Model ◽  
Simulation Results ◽  
Processing Steps

A mathematic model of the electric servo system was founded in this paper and several groups of data collection and data processing were executed to check up the model veracity. This paper described the data processing steps and analyzed the contrast of test and simulation results. This model is effectual to describe the performance of this kind of servo in respect that the results are mainly consentaneous.

scholarly journals Multicell Power Supplies for Improved Energy Efficiency in the Information and Communications Technology Infrastructures

2021 ◽  
Author(s):  
Michael Chrysostomou ◽  
Nicholas Christofides ◽  
Stelios Ioannou ◽  
Alexis Polycarpou
Keyword(s):  
Energy Demand ◽  
Information And Communications Technology ◽  
Power Supplies ◽  
Communications Technology ◽  
Cell Structures ◽  
Full Power ◽  
Overall Efficiency ◽  
Simulation Results ◽  
The Individual ◽  
Theoretical Results

The rapid growth of the Information and Communications Technology (ICT) sector requires additional infrastructure, such as more micro-datacenters and telecom stations, to support the higher internet speeds and low latency requirements of 5G net-works. The increased power requirements of the new ICT technologies necessitate the proposal of new power supplies in an attempt to retain the increase in energy demand and running costs. This work provides an in-depth theoretical analysis on the losses of the individual stages of commercially available PSU and proposes a new multicell PSU, Buck-PFC converter, which offers a higher overall efficiency at varying load levels. The theoretical results are verified using simulation results, via PSIM Thermal Module, and using experimental data. The results indicate that multi-cell structures can improve the overall PSU ef-ficiency by 1.2% at 50% rated power and more than 2.1% at full power. Finally, taking into consideration the economic implica-tions of this study, it is shown that the proposed multicell structure may increase the PSU costs by 10.78% but the payback pe-riod is in the order of just 3.3 years.

scholarly journals Simulation and Measurement Studies of The Vdes System’s Terrestrial Component

2019 ◽  
Vol 26 (1) ◽  
pp. 95-106 ◽  
Author(s):  
Krzysztof Bronk ◽  
Patryk Koncicki ◽  
Adam Lipka ◽  
Dominik Rutkowski ◽  
Błażej Wereszko
Keyword(s):  
Data Transmission ◽  
Data Exchange ◽  
Technical Information ◽  
Theoretical Data ◽  
Current Version ◽  
Coding Gain ◽  
Exchange System ◽  
Measurement Results ◽  
Simulation Results ◽  
Theoretical Results

Abstract In the paper, the measurement and simulation results of the VDES (VHF Data Exchange System) terrestrial component are discussed. It is anticipated that VDES will be one of the major solutions for maritime communications in the VHF band and its performance will be sufficient to fulfill the requirements of the e-navigation applications. The process of the VDES standardization (ITU R, IALA) has not been officially completed yet, but substantial amount of technical information about the future system’s terrestrial component (VDE-TER) is already available. The paper is divided into three general parts: (a) theoretical presentation of the system’s physical layer and the radio channels applicable to VDES, (b) simulation results (BER, BLER, channel delay between two propagation paths and its influence on bit rates) and (c) measurement results (useful ranges, BER). It turned out that in real maritime conditions, the VDES system can offer ranges between 25 and 38 km for the configurations assumed during the measurement campaign. Those results are generally compliant with the theoretical data in the line-of-sight conditions. In the NLOS scenarios, where fading becomes the dominant phenomenon, the discrepancies between the measurements and the theoretical results were more significant. The obtained results confirmed that VDES provides a large coding gain, which significantly improves the performance of data transmission and increases the bit rate compared to the existing maritime radiocommunication solutions. It should be noted that the results presented in the article were used by the IALA while developing the current version of the VDES specification.

Computation of Madalines' Sensitivity to Input and Weight Perturbations

2006 ◽  
Vol 18 (11) ◽  
pp. 2854-2877 ◽  
Author(s):  
Yingfeng Wang ◽  
Xiaoqin Zeng ◽  
Daniel So Yeung ◽  
Zhihang Peng
Keyword(s):  
Probability Theory ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
Analytical Formula ◽  
Single Neurons ◽  
Important Measure ◽  
Simulation Results ◽  
Theoretical Results ◽  
Good Agreement

The sensitivity of a neural network's output to its input and weight perturbations is an important measure for evaluating the network's performance. In this letter, we propose an approach to quantify the sensitivity of Madalines. The sensitivity is defined as the probability of output deviation due to input and weight perturbations with respect to overall input patterns. Based on the structural characteristics of Madalines, a bottomup strategy is followed, along which the sensitivity of single neurons, that is, Adalines, is considered first and then the sensitivity of the entire Madaline network. Bymeans of probability theory, an analytical formula is derived for the calculation of Adalines' sensitivity, and an algorithm is designed for the computation of Madalines' sensitivity. Computer simulations are run to verify the effectiveness of the formula and algorithm. The simulation results are in good agreement with the theoretical results.

scholarly journals Consensus of Fractional-Order Multiagent Systems with Nonuniform Time Delays

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jun Liu ◽  
Kaiyu Qin ◽  
Wei Chen ◽  
Ping Li ◽  
Mengji Shi
Keyword(s):  
Multiagent Systems ◽  
Fractional Order ◽  
Time Delays ◽  
External Environment ◽  
Domain Theory ◽  
Dynamical Model ◽  
Integer Order ◽  
The Laplace Transform ◽  
Simulation Results ◽  
Theoretical Results

Due to the complex external environment, many multiagent systems cannot be precisely described or even cannot be described by an integer-order dynamical model and can only be described by a fractional-order dynamical model. In this paper, consensus problems are investigated for two types of fractional-order multiagent systems (FOMASs) with nonuniform time delays: FOMAS with symmetric time delays and undirected topology and FOMAS with asymmetric time delays and directed topology. Employing the Laplace transform and the frequency-domain theory, two delay margins are obtained to guarantee the consensus for the two types of FOMAS, respectively. These results are also suitable for the integer-order dynamical model. Finally, simulation results are provided to illustrate the effectiveness of our theoretical results.

Dynamic Modeling and Simulation of Rough Cylindrical Micro/Nanoparticle Manipulation with Atomic Force Microscopy

2014 ◽  
Vol 20 (6) ◽  
pp. 1692-1707 ◽  
Author(s):  
Moharam H. Korayem ◽  
Hedieh Badkoobeh Hezaveh ◽  
Moein Taheri
Keyword(s):  
Critical Force ◽  
Cylindrical Particle ◽  
Force Microscopy ◽  
Real Area Of Contact ◽  
Atomic Force ◽  
Rough Substrate ◽  
Simulation Results ◽  
Afm Probe ◽  
Cylindrical Particles ◽  
Simulation Condition

AbstractIn this paper, the process of pushing rough cylindrical micro/nanoparticles on a surface with an atomic force microscope (AFM) probe is investigated. For this purpose, the mechanics of contact involving adhesion are studied first. Then, a method is presented for estimating the real area of contact between a rough cylindrical particle (whose surface roughness is described by the Rumpf and Rabinovich models) and a smooth surface. A dynamic model is then obtained for the pushing of rough cylindrical particles on a surface with an AFM probe. Afterwards, the process is simulated for different particle sizes and various roughness dimensions. Finally, by reducing the length of the cylindrical particle, the simulation condition is brought closer to the manipulation condition of a smooth spherical particle on a rough substrate, and the simulation results of the two cases are compared. Based on the simulation results, the critical force and time of manipulation diminish for rough particles relative to smooth ones. Reduction in the aspect ratio at a constant cross-section radius and the radius of asperities (height of asperities based on the Rabinovich model) results in an increase in critical force and time of manipulation.

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