Papers by Keyword: Computer Aided Design (CAD)

Abstract: To estimate the precise mechanical properties of the three-dimensional (3D) braided composite, a geometric study is needed. Owing to the complexity of the yarn paths inside the preform, the geometric modeling for 3D braided composite is always time consuming. In this paper, an efficient method, namely preform boundary reflection (PBR) method, is proposed for motion model construction in geometric study. Furthermore, the CAD simulation system was developed for integral geometric descriptions of 3D braided preform with different parameters. Compared with the traditional method, the novel method significantly simplifies the simulation process without affecting the precision of geometric structure. As a result, the structure design for composite preform is effectively accelerated. The new method establishes the foundation of microstructure and mechanical properties analysis for the preforms with complex geometric structures.

Abstract: In recent decades, renewable energy has been one of the major theme for researchers around the globe. In this research, one of the main objective is to verify on the structural reliability of the Mini Hydroelectric device. At first, the Engineering Design Process has been utilised in order to run the overall project efficiently, beginning from the conceptual stage until data analysis. As a result, the preliminary design has been accomplished within one year duration; with the support of 3D CAD design tool (Catia). Based from the simulation result, majority of the stress concentrates around the area between shaft and insert hole portion. The product (especially the inner parts) also able to withstand until 2 bar of water pressure, achieving minimum design safety factor of 1.3. Overall, the simulation result is always severe compared to theoretical calculation. This highlights the importance of using FEA simulation software such as ANSYS Workbench in validating the structural analysis result. In near future, by focusing on improving the performance of critical parts and areas; more opportunities especially in terms of design optimization is positively viewed.

Abstract: The object of this study is to utilize FE-SPH method to simulate the dynamic behavior of bioprosthetic heart valve during systole. Two kind of bioprosthetic heart valve numerical models are designed based on membrane theory, and they are represented by FE mesh, the blood is modelled as SPH particles. The interaction between the blood and bioprosthetic heart valve is carried out with contact algorithms. Results show that: when the valve leaflets are opening, compared with that of spherical valve, the stress and strain states of cylindrical valve are unstable, and the peak Von Mises is also higher, which high peak stress and its instability may induce the fatigue of valve. The valve opening time of columnar valve leaflets is longer than that of spherical ones, which reduces the blood ejection time. Above results indicate that spherical valve is superior to cylindrical valve. The FE-SPH method is capable of simulating the fluid structure interaction between the bioprosthetic heart valve and blood during the systole.

Abstract: In China, for 3D stratum visualization computer assignment design software research is still very backward, but does not prevent him is widely used in geological exploration. This paper introduces the concept of computing into visual and significance of three-dimensional visualization and numerical model artifacts, computer software and examples in this paper, the 3D stratum visualization computer assignment design software in the actual application of geological exploration.

Abstract: The paper presents a structure and functions of an expert system for aided design of rice harvester chassis systems. It was developed on basis of a detailed analysis of the design process, including knowledge bases regarding chassis systems automated design, a community of parameterized parts and assemblies and interference engine. In the creation of the system, Visual C++, Pro/Engineering and Oracle database were used. This system is characterized by a rule-oriented representation of knowledge, forward chaining inference methods, and graphic representation of the design results by parameterized technology. The industrial application of this system proved its high reliability and accuracy.

Abstract: In time past, designs of shafts were conservative in approach as relatively low working stresses were employed to cover up for unknown “Factors of Ignorance”. [1]. And where high stresses are involved, greater shaft dimension is employed for such design. This approach necessarily made the production cost high as quite a lot of materials are involved in such production. The primary reason for such approach is to safeguard the shaft failure in most operations. Unfortunately, the mechanism of failure mode was not well understood and because most of the applications in which shafts are employed are of great importance, which in some cases affects life negatively (i.e. involving loss of lives) and distortion of operations. Despite all these developments, designers are still faced with the problems of working with large numbers of formulas, computations and iteration procedures involved in the design of shafts. These have made the design procedures of shafts both cumbersome and rigorous, hence time consuming. This problem becomes more pronounced if the designer is interested in seeing the effects of the variation of one or more design parameter, this means he has to start again from scratch. Fortunately, these problems can be overcome if the various advantages, utilities and flexibilities which modern high – speed micro – computers offer are put into good use in the design of shafts. This study was carried out to design shaft under various loading conditions using Computer Aided Design, and results gotten proved that it saves wastage of materials, and it safes time as well A software package (or program) was developed using the formulas initially derived and a numerical procedure for computing the deflection using the double integration methods. The Programming language used was Visual Studio C#. This objective was achieved in part as the program so developed satisfactorily handle design based on strength and safety of the shaft.

Abstract: This paper narrates the basic principle of the computer aided design for car styling and analyzes the current status of building the high-quality surfaces in the computer aided design for car styling and “the basic process model of digital car styling” .to build “the sbasic process model based on CAS digital modeling. It points out the research content and method of the car digital model and provides theoretical basis for the research of the car styling digital model. In the conventional early design of car styling, generally the revision of design schemes consumes much time and energies. Revisions have been continuously made from the initial creative idea to the later clay model before entering into the engineering design. With the rapid development of the computer technology, the digital technology has become the leading one for the car styling development. During the design process, the digital design of car styling has evolved from the rendering into the engineering design. In order to convey the styling idea that expresses in the design sketch in a rapid and accurate way, it requires a clear expression system and based on the system, the digital model is made. Otherwise, even the good modeling technology and the high-quality surfaces become useless without clearly expressing the idea. The computer aided design for car styling is advanced, but there still exist many problems. The paper aims to put forward a rapidly modeling method of high quality car surfaces based on digital modeling and explore its feasibility during the actual application, by analyzing the current status of building the high-quality surfaces in the computer aided design for car styling and the basic process of the computer aided design for car styling and discussing problems existed during the expression of the design, as well as combining other methods of the computer aided design in other fields.

Abstract: Aimed at disadvantages of tedious work of the gear teeth design, Visual Fortran is taken as the development platform, and design data are stored and managed by self-developed program and database technology. A CAD System for Gear Teeth named GTCS is researched and developed. The system integrates designing and drawing in a body, and fully uses the powerful numerical calculation function of Visual Fortran and the function of Windows interface design, as well as the secondary development function of AutoCAD and database technology, etc. The software can realize designing and calculating of involute gear teeth and transmission mechanism, automatic drawing and various kinds of results post-processing. Results show that the research results greatly improved the efficiency and quality of the design. The result documents are easily accessible by other structural analysis software (such as SolidWorks, ANSYS, ADINA, etc) and similar design software, and convenient to use for the follow-up work.

Abstract: This paper introduces data formats of DWG files, and offers simple description of each separate part of the file. People always use Autodesk AutoCAD to view and get information of DWG files. This paper tries to get the information without relevant platform of AutoCAD, and make use of the information to do some work about three-dimensional modeling of DWG files.

Abstract: Currently, many designers for pipeline network, such as the municipal drainage pipelines, oil/gas transport pipelines, use AutoCAD to design their drawings which demonstrated in a 2D view. For professionals, it’s easy to view and modify their design. But for common users who usually have little professional knowledge on pipeline design, a 3D scene view is more intuitive. To this end, we propose the architecture and implementation of pipeline network information that has facilities such as reconstructing the 3D scene of a pipe network from 2D AutoCAD files (.dwg files).