scholarly journals A Novel Shape-Adjustable Surface and Its Applications in Car Design

2019 ◽  
Vol 9 (11) ◽  
pp. 2339 ◽  
Author(s):  
Fan Liu ◽  
Xiaomin Ji ◽  
Gang Hu ◽  
Jing Gao
Keyword(s):  
Computer Aided Design ◽  
Aerodynamic Drag ◽  
Design Method ◽  
The Body ◽  
Design Stage ◽  
Shape Parameters ◽  
Characteristic Lines ◽  
Aerodynamic Drag Coefficient ◽  
Computational Fluid Dynamics Cfd ◽  
Aided Design

In this paper, a new parameterized surface, termed SQ-Coons surface, is proposed according to the build mode of Coons patch. The surface is always interpolated to the boundary curves, and its shape details could be controlled by the shape parameters in CE-Bézier basis functions, which makes it suitable for styling design in computer aided design (CAD). In order to exert its geometric advantages in car design, a simplified body CAD template based on characteristic lines is built according to common vehicle features. The template is built entirely from SQ-Coons surfaces, so that the overall style and detail shapes could all be modified by the control points and shape parameters of each surface. By analyzing the curvature of fifty commercial car types generated through the template and various parameters, a set of methods for constraining the range of shape parameters is proposed. On this basis, as an example, the four shape parameters of the hood surface in one model are used as variables to optimize the body shape to achieve the lowest possible aerodynamic drag coefficient in computational fluid dynamics (CFD). The results show that the design method, combining the new surface and the model template, could reflect the modeling characteristics of different cars, and improve the design and scheme adjustment efficiency in the conceptual design stage.

scholarly journals Thermal studies of vacuum panels of cellular structure of a passenger car

2021 ◽  
Vol 34 (06) ◽  
pp. 1707-1713
Author(s):  
Anatoly N. Balalaev ◽  
Maria A. Parenyuk ◽  
Dmitry M. Timkin
Keyword(s):  
Computer Aided Design ◽  
Thermal Studies ◽  
The Body ◽  
Design Stage ◽  
New Production ◽  
Passenger Rail ◽  
Production Technologies ◽  
Manufacturing Technologies ◽  
Aided Design ◽  
The Heat Transfer Coefficient

Aluminum alloys and composite materials are used in the body structures of modern passenger railway cars, which required the use of new manufacturing technologies: extrusion, pultrusion, etc. The use of new materials and new production technologies is changing the design requirements of passenger rail cars. The use of computer-aided design systems, in particular, SolidWorks Simulation, allows you to optimize the profile of cellular panels used in the construction of the body of a passenger railway car and obtained by extrusion or 3-D printing. Purpose of this work is to optimize the design stage of the enclosing structures of the body of a passenger railway car made of cellular profile panels, which can significantly reduce the heat transfer coefficient of the body walls and their mass, as well as provide the necessary strength conditions. Optimal profile of the vacuum panel, consisting of two rows of hexagonal cells, provides, according to calculations, the value of the specific thermal resistance R = 2.922 (m2 K)/W, which is 16.5% more than that of the existing body structure of a passenger rail car.

Design of Method Database for Correction System of Intelligent Womens Jacket Pattern

2013 ◽  
Vol 796 ◽  
pp. 549-553
Author(s):  
Xin Lu
Keyword(s):  
Body Size ◽  
Computer Aided Design ◽  
Design Method ◽  
Geometric Model ◽  
Basic Research ◽  
Active Role ◽  
The Body ◽  
Design System ◽  
Computer Aided ◽  
Aided Design

The automatic creation of garment parametric computer aided design (PCAD) pattern to special body size is rarely classified and need to be finished with man machine interface at present. This has become a critical and challenging issue to hinder the intelligence process of the garment computer aided design (CAD). In this paper, the basic research aimed at the automatic correction pattern of the special size on the womens jacket CAD system was investigated. The popular special size of women trunk and pattern amendment was selected as research subject, and the relationship between the body characteristics and coat pattern Fig. were set up. The full-scale constraint was developed and the expertise description about womens jacket patterns were finished with the parametric design method based constraint. The mathematic formula and logical definition relation are used to establish relationship with the formed model characteristics of womens jacket patterns. The system then carry and keep the design of womens jacket pattern and the correction logic, and finish the creation and correction of the geometric model to womens jacket pattern. The expertise knowledge of womens jacket pattern correction is applied by the design of method database. The paper performs the basic research and analysis for the rules database creation in the PCAD system, and makes it possible to the research of intelligent womens jacket pattern design system based body size. It will play an active role to transform traditional design concepts and means.

scholarly journals Parametric Model for Kitchen Product Based on Cubic T-Bézier Curves with Symmetry

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 505
Author(s):  
Xin Sun ◽  
Xiaomin Ji
Keyword(s):  
Computer Aided Design ◽  
Parametric Method ◽  
Design Stage ◽  
Shape Parameters ◽  
Bezier Curves ◽  
Bézier Curves ◽  
Cad Cam ◽  
G2 Continuity ◽  
Kitchen Cabinet ◽  
Aided Design

The parametric method of product design is a pivotal and practical technique in computer-aided design and manufacturing (CAD/CAM) and used in many manufacturing sectors. In this paper, we presented a novel parametric method to design a kitchen product in the residential environment, a kitchen cabinet, by using cubic T-Bézier curves with constraints of geometric continuities. First, we introduced a class of cubic T-Bézier curves with two shape parameters and derived the G1 and G2 continuity conditions of the cubic T-Bézier curves. Then, we constructed shape-controlled complex contour curves of the kitchen cabinet by using closed composite cubic T-Bézier curves. The shapes of the contour curves can be adjusted intuitively and predictably by altering the values of the shape parameters. Finally, we studied shape optimization and representation of ellipses for the contour curves of the kitchen cabinet by finding optimal shape parameters and applicable control points respectively. The provided modeling examples showed that our method in this paper can improve the design and scheme adjustment effectively in the conceptual design stage of kitchen products.

An Integrated Ship Re-Design/Modification Strategy

2019 ◽  
Vol 161 (A1) ◽  
Keyword(s):  
Computer Aided Design ◽  
Modular Design ◽  
Ship Hull ◽  
Cfd Model ◽  
Hull Form ◽  
Design Modification ◽  
Technical Parameters ◽  
Computational Fluid Dynamics Cfd ◽  
Bulbous Bow ◽  
Aided Design

Herein, we present an integrated ship re-design/modification strategy that integrates the ‘Computer-Aided Design (CAD)’ and ‘Computational Fluid Dynamics (CFD)’ to modify the ship hull form for better performance in resistance. We assume a modular design and the ship hull form modification focuses on the forward module (e.g. bulbous bow) and aft module (e.g. stern bulb) only. The ship hull form CAD model is implemented with NAPA*TM and CFD model is implemented with Shipflow**TM. The basic ship hull form parameters are not changed and the modifications in some of the technical parameters because of re-designed bulbous bow and stern bulb are kept at very minimum. The bulbous bow is re-designed by extending an earlier method (Sharma and Sha (2005b)) and stern bulb parameters for re-design are computed from the experience gained from literature survey. The re-designed hull form is modeled in CAD and is integrated and analyzed with Shipflow**TM. The CAD and CFD integrated model is validated and verified with the ITTC approved recommendations and guidelines. The proposed numerical methodology is implemented on the ship hull form modification of a benchmark ship, i.e. KRISO container ship (KCS). The presented results show that the modified ship hull form of KCS - with only bow and stern modifications - using the present strategy, results into resistance and propulsive improvement.

Highways Design Taking into Account Climatic Features in the Route Area

2021 ◽  
pp. 125-136
Author(s):  
Т. В. Самодурова ◽  
Н. Ю. Алимова ◽  
О. А. Волокитина ◽  
О. В. Гладышева
Keyword(s):  
Bearing Capacity ◽  
Computer Aided Design ◽  
Systematic Approach ◽  
Weather Conditions ◽  
Design Stage ◽  
Design System ◽  
Computer Aided ◽  
Calculation Methodology ◽  
Aided Design ◽  
Climatic Features

Постановка задачи. Для получения оптимальных проектных решений, удовлетворяющих условиям безопасности движения в сложных погодных условиях, необходимо сравнение вариантов автомобильных дорог по условиям снегонезаносимости. Такие расчеты должны стать составной частью системы автоматизированного проектирования САПР-АД. Результаты. Предложен системный поход к решению задачи, определен перечень информации, необходимой для проведения расчетов. Выполнен анализ результатов исследований по снегозаносимости дорог, проводимых в России и за рубежом. Предложены расчетные схемы и модели для оценки вариантов продольного профиля и земляного полотна автомобильной дороги по снегозаносимости. Предложены решения для оценки вариантов плана трассы с использованием карт с расчетными параметрами метелей. Выводы. Реализация предложенной методики проведения расчетов позволит на стадии проектирования оценить варианты автомобильной дороги по условиям снегозаносимости. Statement of the problem. In order to obtain optimal design solutions that meet the conditions of safety traffic in difficult weather conditions, it is necessary to compare the options of highways according to the snow tolerance conditions. Such calculations should become an integral part of the CAD-AD computer-aided design system. Results. A systematic approach to solving the problem is set forth, a list of information necessary for calculations is identified. The results analysis of studies on the snow-bearing capacity of roads conducted in Russia and abroad is carried out. Calculation schemes and models are suggested to evaluate options for the longitudinal profile and the roadbed for the snow-bearing capacity. Solutions for evaluating variants of the route plan using maps with calculated parameters of snowstorms are proposed. Conclusions. The implementation of the proposed calculation methodology will make it possible at the design stage to evaluate the options of the highway according to the conditions of the snow-bearing capacity.

Design of Mine Ventilation Systems Based on Artificial Intelligence

2014 ◽  
Vol 614 ◽  
pp. 107-112
Author(s):  
Xiao Yu Yin ◽  
Xian Ping Xie ◽  
Zhen Li ◽  
Jian Gong Li ◽  
Ting Jun Wang ◽  
...  
Keyword(s):  
Expert System ◽  
Computer Aided Design ◽  
Design Method ◽  
Mine Ventilation ◽  
Design System ◽  
Knowledge Based ◽  
Aided Design ◽  
And Control ◽  
Intelligent Computer ◽  
Ventilation Systems

Expert systems, or knowledge based systems, are programs in which the answer to a user-posed question is reached by logical or plausible inference rather than strictly by calculation, although calculation routines can form a major part of an expert system. Based on the integration of expert system technology and optimization technology, an intelligent computer aided design method for mine ventilation systems is proposed in this paper. Firstly, the structure and control algorithm of the intelligent design system are explored. Secondly, the knowledge types required for the mine ventilation expert system and the acquiring method of knowledge are discussed. Finally, the inference method of this expert system is put forward.

scholarly journals Analog Circuit Design Automation Tool Using Genetic Algorithms

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Y. M. A. Khalifa ◽  
D. H. Horrocks
Keyword(s):  
Genetic Algorithms ◽  
Circuit Design ◽  
Analog Circuits ◽  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Analog Circuit ◽  
Search Space ◽  
Design Stage ◽  
Specific Frequency ◽  
Aided Design

An investigation into the application of Genetic Algorithms (GA) for the design of electronic analog circuits is presented in this paper. In this paper an investigation of the use of genetic algorithms into the problem of analog circuits design is presented. In a single design stage, circuits are produced that satisfy specific frequency response specifications using circuit structures that are unrestricted and with component values that are chosen from a set of preferred values. The extra degrees of freedom resulting from unbounded circuit structures create a huge search space. It is shown in this paper that Genetic Algorithms can be successfully used to search this space. The application chosen is a LC all pass ladder filter circuit design.Key Words: Computer-Aided Design, Analog Circuits, Artificial Intelligence.

scholarly journals Design Method of Circular Weft-Knitted Jacquard Fabric Based on Jacquard Module

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Peixiao Zheng ◽  
Gaoming Jiang ◽  
Honglian Cong
Keyword(s):  
Mathematical Modeling ◽  
Computer Aided Design ◽  
Theoretical Basis ◽  
Design Method ◽  
Two Dimensional ◽  
Design Procedures ◽  
Rapid Design ◽  
Computer Aided ◽  
Aided Design

Abstract Recently, there is an increasing interest in design of circular weft jacquard because of the pursuit of fashion and comfort. Aiming at the complexity of the computer-aided design method of the existing circular weft-knitted jacquard fabrics, which is not conducive to the rapid design and intelligible for designers, a design method was proposed to transform pattern notation into knitting diagram efficiently, which was based on knitting rules and its creation as a set of jacquard modules. Knitting characteristics of jacquard fabrics were studied as a precondition. On this basis, the design procedures of jacquard modules were analyzed and illustrated by taking tricolor bird's eye backing jacquard as an example. Jacquard modules with various jacquard effects were designed and stored in a jacquard module database. To mathematically describe pattern notation, knitting diagram, and jacquard module, two-dimensional matrixes were established by the method of mathematical modeling, and a corresponding algorithm for the transformation of the pattern to knitting information according to the knitting rules of jacquard modules, which can be applied to ordinary jacquard fabrics was summarized. The project of tricolor circular weft-knitted jacquard with bird's eye in the reverse and four-color air-layer jacquard were taken for instance to verify the models and algorithm. The results obtained show that the approach can efficiently and conveniently realize the designation and machine-knitting of weft-knitted jacquard fabric, which provide a theoretical basis and notation of modeling for the computer-aided design of circular weft-knitted jacquard fabrics.

Optimal Design of Semisubmersible’s Form Based on Systems Analysis

1984 ◽  
Vol 106 (4) ◽  
pp. 524-530 ◽  
Author(s):  
S. Akagi ◽  
R. Yokoyama ◽  
K. Ito
Keyword(s):  
Optimal Design ◽  
Computer Aided Design ◽  
Optimization Problem ◽  
Design Method ◽  
Gradient Algorithm ◽  
Interpretive Structural Modeling ◽  
Reduced Gradient ◽  
Optimal Design Method ◽  
Generalized Reduced Gradient ◽  
Aided Design

With the objective of developing a computer-aided design method to seek the optimal semisubmersible’s form, hierarchical relationships among many design objectives and conditions are investigated first based on the interpretive structural modeling method. Then, an optimal design method is formulated as a nonlinear multiobjective optimization problem by adopting three mutually conflicting design objectives. A set of Pareto optimal solutions is derived numerically by adopting the generalized reduced gradient algorithm, and it is ascertained that the designer can determine the optimal form more rationally by investigating the trade-off relationships among design objectives.

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