• Title/Summary/Keyword: acd

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Shock analysis of a new ultrasonic motor subjected to half-sine acceleration pulses

  • Hou, Xiaoyan;Lee, Heow Pueh;Ong, Chong Jin;Lim, Siak Piang
    • Advances in Computational Design
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    • v.1 no.4
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    • pp.357-370
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    • 2016
  • This paper aims to examine the dynamic response of a newly designed ultrasonic motor under half-sine shock impulses. Impact shock was applied to the motor along x, y or z axis respectively with different pulse widths to check the sensitivity of the motor to the shocks in different directions. Finite Element Analysis (FEA) with the ANSYS software was conducted to obtain the relative displacement of a key point of the motor. Numerical results show that the maximum relative displacement is of micro meter level and the maximum stress is five orders smaller than the Young's modulus of the piezo material, which proves the robustness of the motor.

2차원도면으로 표현된 각주형 부품의 특징형상인식

  • 박재민;이충수;박경진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.426-431
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    • 1997
  • Features are well recognized to play an important role for the integration of ACD and CAPP. Majority of pervious works for the feature recognition for prismatic part is based on 3D solid model. But in real factories, 2D drawing are used more than 3D drawings. In this paper, we develope an algorithm of the feature recognition on prismatic parts in 2D drawings, using by the graph method and the heuristic algorithm. Previous algorithms have some conflicts at feature interaction. In this paper, elements are grouped into connection by the graph method. Then features are recognized by using these grouped elements and their relationships of front and side-view. For resolving the problem of feature interaction, the element graphs are modified by an deloped algorithm. This algorithm is applied to a CAPP system for milling process planning.

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Finite element modeling of multiplyconnected three-dimensional areas

  • Polatov, Askhad M.;Ikramov, Akhmat M.;Razmukhamedov, Daniyarbek D.
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.277-289
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    • 2020
  • This article describes the technology for constructing of a multiply-connected three-dimensional area's finite element representation. Representation of finite-element configuration of an area is described by a discrete set that consist of the number of nodes and elements of the finite-element grid, that are orderly set of nodes' coordinates and numbers of finite elements. Corresponding theorems are given, to prove the correctness of the solution method. The adequacy of multiply-connected area topology's finite element model is shown. The merging of subareas is based on the criterion of boundary nodes' coincidence by establishing a simple hierarchy of volumes, surfaces, lines and points. Renumbering nodes is carried out by the frontal method, where nodes located on the outer edges of the structure are used as the initial front.

Modeling methods used in bioenergy production processes: A review

  • Akroum, Hamza;Akroum-Amrouche, Dahbia;Aibeche, Abderrezak
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.323-347
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    • 2020
  • The enhancements of bioenergy production effectiveness require the comprehensively experimental study of several parameters affecting these bioprocesses. The interpretation of the obtained experimental results and the estimation of optimum yield are extremely complicated such as misinterpreting the results of an experiment. The use of mathematical modeling and statistical experimental designs can consistently supply the predictions of the potential yield and the identification of defining parameters and also the understanding of key relationships between factors and responses. This paper summarizes several mathematical models used to achieve an adequate overall and maximal production yield and rate, to screen, to optimize, to identify, to describe and to provide useful information for the effect of several factors on bioenergy production processes. The usefulness, the validity and, the feasibility of each strategy for studying and optimizing the bioenergy-producing processes were discussed and confirmed by the good correlation between predicted and measured values.

An investigation of non-linear optimization methods on composite structures under vibration and buckling loads

  • Akbulut, Mustafa;Sarac, Abdulhamit;Ertas, Ahmet H.
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.209-231
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    • 2020
  • In order to evaluate the performance of three heuristic optimization algorithms, namely, simulated annealing (SA), genetic algorithm (GA) and particle swarm optimization (PSO) for optimal stacking sequence of laminated composite plates with respect to critical buckling load and non-dimensional natural frequencies, a multi-objective optimization procedure is developed using the weighted summation method. Classical lamination theory and first order shear deformation theory are employed for critical buckling load and natural frequency computations respectively. The analytical critical buckling load and finite element calculation schemes for natural frequencies are validated through the results obtained from literature. The comparative study takes into consideration solution and computational time parameters of the three algorithms in the statistical evaluation scheme. The results indicate that particle swarm optimization (PSO) considerably outperforms the remaining two methods for the special problem considered in the study.

Advanced controller design for AUV based on adaptive dynamic programming

  • Chen, Tim;Khurram, Safiullahand;Zoungrana, Joelli;Pandey, Lallit;Chen, J.C.Y.
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.233-260
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    • 2020
  • The main purpose to introduce model based controller in proposed control technique is to provide better and fast learning of the floating dynamics by means of fuzzy logic controller and also cancelling effect of nonlinear terms of the system. An iterative adaptive dynamic programming algorithm is proposed to deal with the optimal trajectory-tracking control problems for autonomous underwater vehicle (AUV). The optimal tracking control problem is converted into an optimal regulation problem by system transformation. Then the optimal regulation problem is solved by the policy iteration adaptive dynamic programming algorithm. Finally, simulation example is given to show the performance of the iterative adaptive dynamic programming algorithm.

Optimization analysis on collection efficiency of vacuum cleaner based on two-fluid and CFD-DEM model

  • Wang, Lian;Chu, Xihua
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.261-276
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    • 2020
  • The reasonable layout of vacuum cleaner can effectively improve the collection efficiency of iron filings generated in the process of steel production. Therefore, in this study, the CFD-DEM coupling model and two-fluid model are used to calculate the iron filings collection efficiency of vacuum cleaner with different inclination/cross-sectional area, pressure drop and inlet angle. The results are as follows: The CFD-DEM coupling method can truly reflect the motion mode of iron filings in pneumatic conveying. Considering the instability and the decline of the growth rate of iron filings collection efficiency caused by high pressure drop, the layout of 75° inclination is suggested, and the optimal pressure drop is 100Pa. The optimal simulation results based on two-fluid model show that when the inlet angle and pressure drop are in the range of 45°~65° and 70Pa~100Pa, larger mass flow rate of iron filings can be obtained. It is hoped that the simulation results can offer some suggestion to the layout of vacuum cleaner in the rolling mill.

Optimal model of transportation for people with disabilities: Conceptual proposal designed in CAD

  • Vergunova, Nataliia;Vergunov, Sergey
    • Advances in Computational Design
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    • v.5 no.4
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    • pp.381-396
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    • 2020
  • This study aimed to develop an optimal model of transportation for people with disabilities. To achieve this goal, powers of research and design should be involved, including CAD software. This paper investigates both: the concept of optimal model of transportation for people with disabilities (functional, ergonomic, constructive, technological and aesthetic solutions included); and its implementation as a fully-fledged 3D-model designed in SolidWorks environment. The optimal model of transportation is complex and consists of two objects. The first object is for indoors that is a wheelchair, the second one is for street driving that is an individual vehicle. The optimal model of transportation is universal and multifunctional, which have become possible with parametric feature-based approach utilized in SolidWorks.

A review of numerical approach for dynamic response of strain gradient metal foam shells under constant velocity moving loads

  • Fenjan, Raad M.;Ahmed, Ridha A.;Hamad, Luay Badr;Faleh, Nadhim M.
    • Advances in Computational Design
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    • v.5 no.4
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    • pp.349-362
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    • 2020
  • Dynamic characteristics of a scale-dependent porous metal foam cylindrical shell under a traveling load have been explored within this article based on a numerical approach. Within the material texture of the metal foams, uniform and non-uniform porosities may be dispersed. Based upon differential quadrature method (DQM) and Laplace transforms, the equations of motion for a shear deformable scale-dependent shell may be solved numerically. Scale-dependent shell modeling has been provided based upon strain gradient elasticity. Solving the equations will give the shell deflection as a function of load speed. Also, it is reported that shell deflection relies on the porosity dispersion and strain gradient influences.

A combined experimental and numerical method for structural response assessment applied to cable-stayed footbridges

  • Kossakowski, Pawel G.
    • Advances in Computational Design
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    • v.2 no.3
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    • pp.143-163
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    • 2017
  • This paper presents a non-destructive testing method for estimating the structural response of cable-stayed footbridges. The approach combines field measurements with a numerical static analysis of the structure. When the experimental information concerning the structure deformations is coupled with the numerical data on the structural response, it is possible to calculate the static forces and the design tension resistance in selected structural elements, and as a result, assess the condition of the entire structure. The paper discusses the method assumptions and provides an example of the use of the procedure to assess the load-carrying capacity of a real steel footbridge. The proposed method can be employed to assess cable-stayed structures including those made of other materials, e.g., concrete, timber or composites.