Research on Computer Aided Design （CAD） Technique and Novel Pattern for Electronic Architectural Drawing and Perspective

With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic architectural drawing and perspective. AUTOCAD drawing soRware because of its versatility and easy entry, in engineering has broad user base, but also because of the basis of general drawing software, often cannot directly use of the existing order efficiently complete professional drawing. We modify the current pattern and introduce our proposed pattern for advancement. The experiment proves the effectiveness of the pattern. In addition, we will conduct more insightful research in the future to nolish the current anoroach.

PSCAD的发电机准同期并列综合实验设计

针对电力系统自动化实验教学中存在的不足,设计了同步发电机准同期并列综合实验。实验模型采用PSCAD/EMTDC,建立了包含发电机及并网系统、原动机及其调速器、励磁系统、准同期并列控制单元、电压向量的动态显示等关键部件。依托实验模型设计了循序渐进的教学实验项目,主要有机组启动与并网的验证性实验、不同并列条件影响的分析性实验、频率差和电压差调节的设计性实验。该实验将电路、电机学、自动控制理论、电力系统分析等多门专业核心课程贯穿起来,提升了学生综合运用知识解决复杂工程问题的能力。

基于CAD/CAE的异形凸模冲头工装设计与优化研究

异形凸模冲头是汽车锁头连接件模具的重要配件,其材料为冷作模具钢DC53,对汽车锁孔冲压有重要作用。传统加工中,加工质量无法保证,生产效率低。设计了专用工装,结合CAD/CAE软件,优化并改进工装结构设计。实际加工对比表明,该工装的设计与优化方案合理,改进工装后,凸模冲头零件生产效率和加工质量均显著提高。该研究对同类异型模具工装设计也具有参考价值。

Computer Aided Design Technology for Convex Faceted Gem Cuts Based on the Half-Edge Data Structure

Aiming to increase the efficiency of gem design and manufacturing, a new method in computer-aided-design (CAD) of convex faceted gem cuts (CFGC) based on Half-edge data structure (HDS), including the algorithms for the implementation is presented in this work. By using object-oriented methods, geometrical elements of CFGC are classified and responding geometrical feature classes are established. Each class is implemented and embedded based on the gem process. Matrix arithmetic and analytical geometry are used to derive the affine transformation and the cutting algorithm. Based on the demand for a diversity of gem cuts, CAD functions both for free-style faceted cuts and parametric designs of typical cuts and visualization and human-computer interactions of the CAD system including two-dimensional and three-dimensional interactions have been realized which enhances the flexibility and universality of the CAD system. Furthermore, data in this CAD system can also be used directly by the gem CAM module, which will promote the gem CAD/CAM integration.

A Computer-aided Design System for Framed-mould in Autoclave Processing

The general computer-aided design (CAD) software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the mould design process, in addition to the material and geometry of the part. A framed-mould computer-aided design system (FMCAD) used in the autoclave moulding process is proposed in this paper. A function model of the software is presented, in which influence factors such as part structure, mould structure, and process parameters are considered; a design model of the software is established using object oriented (O-O) technology to integrate the stiffness calculation, temperature field calculation, and deformation field calculation of mould in the design, and in the design model, a hybrid model of mould based on calculation feature and form feature is presented to support those calculations. A prototype system is developed, in which a mould design process wizard is built to integrate the input information, calculation, analysis, data storage, display, and design results of mould design. Finally, three design examples are used to verify the prototype.

Application of computer-aided engineering optimum design method in aluminum profile extrusion mould

The finite element analysis and the optimum design of aluminum profile extrusion mould were investigated using the ANSYS software and its parameterized modeling method. The optimum dimensions of the mould were obtained. It is found that the stress distribution is very uneven, and the stress convergence is rather severe in the bridge of the aluminum profile extrusion mould. The optimum height of the mould is 70.527 mm, and the optimum radius of dividing holes are 70.182 mm and 80.663 mm. Increasing the height of the mould in the range of 61.282 mm to 70.422 mm can prolong its longevity, but when the height is over 70.422 mm, its longevity reduces.

Computer-aided Design and Custom-made Guide in Corrective Osteotomy for Complex Femoral Deformity

Preoperative planning of corrective osteotomy with traditional radiography has limitations in regards to determining the ideal osteotomy location and orientation in three-dimensional femoral deformities. Though a successful operation can be planned preoperatively, intraoperative contingencies might adhere to the procedural plan in the performance of operation. To efficiently perform a planned procedure, proposed is a design to implement three-dimensional reconstruction photography, based on computer-tomography (CT) scan. A custom-made guide was designed to navigate the osteotomy as planned, and additionally, a personalized intramedullary nail was used for fixation after osteotomy. Three-dimensional (3D) photography of deformed femur was established based on the CT dataset and transferred into 3D photography processing software for further planning. Osteotomy planes were designed and adjusted at deformity sites to correct the 3D deformities. The methodology of a custom-made osteotomy guide was introduced in femoral corrective osteotomy, for the first time, to navigate the operation as planned. After the virtual osteotomy and reduction of bone segments, the parameters of a custom-made intramedullary nail were measured for manufacturing. Findings Virtual operation in computer shows complete correction of the 3D deformity. The osteotomy guide, obtained by rapid-prototyping techniques, navigates mimicking surgery on rapid-prototyping model of the involved femur as planned. Internal fixation was achieved using the custom-made intramedullary nail. Interpretation three-dimensional visualization introduces an advantage in preoperative planning for corrective osteotomy of 3D femoral deformity, and the custom-made osteotomy guide is crucial to realize such a deliberate plan during the actual procedures. The internal fixator, such as an intramedullary nail, can be modified or personalized for fixation in unique cases.

DESIGN OBJECT MODEL AND DESIGN PROCESS MODEL OF COMPUTER AIDED AIRCRAFT CONCEPTUAL DESIGN SYSTEM

The concept and basic requirement of computer aided design, the charac-ters and requirements of computer aided aircraft conceptual design system are describedin this paper. The first thing in developing a design system is to create the models. A de-sign m

COMPUTER-AIDED DESIGN OF ADAPTIVE PULSED ARC WELDING OF ROOT WELDS BY MELTING ELECTRODE

The purpose of computer-aided design of new adaptive pulsed arc technologies of welding is: to de- sign optimum algorithms of pulsed control over main energy parameters of welding.It permits:to in- crease welding productivity, to stabilize the welding regime, to control weld formation,taking into ac- count its spatial position, to proveal specie strength of the welded and coatings. Computer- aided design reduces the time of development of new pulsed arc technology:provides the optimization of technological referes according to the operating conditions of welded joints,the prediction of the ser- vice life of the welds.The developed methodology of computer-aided design of advanced technologies, models, original software, adaptive algorithms of pulsed control, and spend equipment permits to regulate penetration,the weld shape, the sizes of heat - affected zone; to predict sired properties and quality of welded joints.

Computer Aided Composition Design of Prehardened-Mould Steel for Plastic

The improvement of machining behavior of prehardened-mould steel for plastic is realized by using computer-aided composition design in this work. The results showed that the matrix composition of large sectional prehardened mould steel for plastic markedly influences the precipitation of non-metallic inclusion and the control of composition aided by Thermo-Calc software package minimizes the amount of detrimental oxide inclusion. In addition the modification of calcium is optimized in the light of composition design.

Case-based intelligent computer aided design system of welding machinery

The procedure during complex system plan design of welding position-locating machine is studied in this pa-per.The main difficulties in designing welding position-locating machine utilizing computer are discussed as well.Amethod of case-based intelligent CAD system for welding position-locating machine(WMICAD)is put forward throughwide resarch on design methodology.Object-oriented programming method is also applied to this system.The basic ideaand realizing method are described.

Computer-Aided Rapid Variant Design System for Hydraulic Support

The paper gives a detail analysis on the necessity of rapid hydraulic support design, and presents a computer-aided rapid variant design system for hydraulic support. The system integrates the type selection and embodiment design of hydraulic support. Case-based reasoning and rule-based reasoning are the main reasoning methods. Several crucial problems are discussed.

A NEW SYSTEM FOR COMPUTER AIDED PATTERN DESIGN——CAPDS

This paper proposes a new computer aided pattern design system(CAPDS)in which a uniformmathematical expression is used to construct different objects. In the geometric model, 3 B-splineis adopted as a line model. The new system with uniform mathematical expression has the distin-guishing features: curve smoothness and fidelity, convenience to process graphic data in thedatabase and etc.. This paper presents the data structure, the program structure and also the implementation.

3-D MODELLING OF COMPUTER AIDED GARMENT DESIGN

This paper describes a method of the computer aided garment design,and discusses 3-D humanbody,wire frame modelling,approaches of expressing and a shading model of the 3-D garment.

Computer-aided designing and manufacturing of advanced steels

Suitable optimization and simulation were performed using a powerful software package with a mature database as well as modern measurement facilities, which led to the successful designing and manufacturing of advanced steels. In the course of designing, the composition of a large section of prehardened mold steel for plastics was estimated so as to lower the quantities of oxide inclusions to change the type of carbides and to raise the machinability. The composition and process were adjusted to obtain satisfactory surface quality for the prevailing galvanization in transformation-induced plas- ticity (TRIP) steel. The refining process of low-carbon steel was simulated in the light of both Thermo-Calc and Factsage. Thermodynamic and kinetic analyses were always conducted during the test and the procedure.

ON CURVED SURFACE APPROXIMATION AND HIDDEN SURFACE ELIMINATION IN 3-D COMPUTER AIDED GARMENT DESIGN

An approximation method for curved surface mannequin and hidden surface eliminationin 3-D computer aided garment design system is described. The mannequin is the basis of the3-D modeling for clothes. In terms of the requirements of computer aided garment design,the authors put forward a method for curved surface approximation in the meaning of leastsquares. Using. this method the computation of geometric modeling is simple andefficient. It is also convenient for curved surface modification and shading.

CAD/CAM玻璃瓷高嵌体修复上颌第一前磨牙大面积缺损的疗效

目的观察计算机辅助设计与制造(CAD/CAM)玻璃瓷高嵌体修复上颌第一前磨牙大面积缺损的疗效。方法回顾性分析2017年2月至2019年6月在烟台市烟台山医院收治的72例上颌第一前磨牙大面积缺损患者作为研究对象,其中男31例、女41例,年龄(38.57±7.21)岁。所有患牙均于一次性根管治疗1周后采用CAD/CAM技术行玻璃瓷高嵌体修复,修复完成后进行24个月随访。分析患者修复后3个月、6个月、12个月、24个月的修复效果及修复后24个月的满意度。统计学方法采用χ2检验。结果修复后3个月,所有患者边缘密合度、修复体缺损、崩瓷、修复体脱落、颜色匹配度、领接关系及牙周发炎均达A级;修复后6个月、12个月、24个月患者不同评价条目B级占比略有上升,但不同时间患者修复效果比较,差异无统计学意义(χ^(2)=0.383,P=0.702)。修复后24个月,上颌第一前磨牙大面积缺损患者的修复体颜色、修复体外形、表面光滑度及高嵌体边缘适合性满意度分别为86.11%(62/72)、98.61%(71/72)、88.89%(64/72)、97.22%(70/72)。结论CAD/CAM玻璃瓷高嵌体为上颌第一前磨牙大面积缺损根管治疗后有效修复方法,值得在临床推广。

Computer-Aided Design of Some Advanced Steels and Cemented Carbides

Thermodynamic and kinetic study on TRIP (transformation induced plasticity) steels, cemented carbides and mold steel for plastics were carried out in order to design modern advanced materials. With the sublattice model, equilibrium compositions of ferrite and austenite phases in TRIP steels, as well as volume fraction of austenite at inter-critical temperatures for different time were calculated. Concentration profiles of carbon, manganese, aluminum and silicon in the steels were also estimated in the lattice fixed frame of reference. The effect of Si and Mn on TRIP was discussed according to thermodynamic and kinetic analyses. In order to understand and produce the graded nanophase structure of cemented carbides, miscellaneous phases in the M-Co-C (M=Ti, Ta, Nb) systems and Co-V-C system were modeled. Solution parameters and thermodynamic properties were listed in detail. The improvement of machining behavior of prehardened mould steel for plastics was obtained by computer-aided composition design. The results showed that the matrix composition of large-section prehardened mould steel for plastic markedly influences the precipitation of non-metallic inclusion and the composition control by the aid of Thermo-Calc software package minimizes the amount of detrimental oxide inclusion. In addition, the modification of calcium was optimized in composition design.

A Method for Solving Computer-Aided Product Design Optimization Problem Based on Back Propagation Neural Network

Because of the powerful mapping ability, back propagation neural network (BP-NN) has been employed in computer-aided product design (CAPD) to establish the property prediction model. The backward problem in CAPD is to search for the appropriate structure or composition of the product with desired property, which is an optimization problem. In this paper, a global optimization method of using the a BB algorithm to solve the backward problem is presented. In particular, a convex lower bounding function is constructed for the objective function formulated with BP-NN model, and the calculation of the key parameter a is implemented by recurring to the interval Hessian matrix of the objective function. Two case studies involving the design of dopamine β-hydroxylase (DβH) inhibitors and linear low density polyethylene (LLDPE) nano composites are investigated using the proposed method.

橡皮障隔离技术在椅旁CAD/CAM瓷嵌体修复治疗中的应用

目的研究橡皮障隔离技术在椅旁计算机辅助设计(CAD)/计算机辅助制作(CAM)瓷嵌体修复治疗中的应用效果。方法选择2020年1月—2022年1月医院牙体牙髓科行椅旁CAD/CAM瓷嵌体修复治疗的患者60例,随机分为研究组和对照组,各30例。对照组按照常规流程操作,使用常规方法进行术野隔离;研究组在操作治疗中运用橡皮障隔离技术。比较两组总治疗时间和不良反应发生情况。结果两组患者的嵌体冠修复体在冠边缘、密合性、咬合关系等方面均良好。研究组总治疗时间(118.83±19.15)min,较对照组(141.26±11.74)min缩短,差异有统计学意义(P<0.05);研究组无不良反应发生,对照组发生1(3.33%)例不良反应。结论橡皮障隔离技术可有效缩短椅旁CAD/CAM瓷嵌体修复治疗时间。