Theoretical Foundations for the Computer-Aided Design System

SIMULATION ◽  
1964 ◽  
Vol 2 (3) ◽  
pp. R-3-R-20
Author(s):  
Douglas T. Ross ◽  
Jorge E. Rodriguez

This work has been made possible through the support extended to the Massachusetts Institute of Technology, Electronic Systems Laboratory, by the Manufacturing Technology Laboratory, ASD, Wright-Patterson Air Force Base, under Contract No. AF-33(600)- 42859. It is published for technical information only and does not necessarily represent the recommendations or conclusions of the sponsoring agency.

Author(s):  
Teruaki Ito ◽  
Alexander H. Slocum

This paper describes two approaches to teaching engaging creative engineering design classes. Both of these classes have evolved over many years using feedback from annual class reviews. One is the computer-aided design class, CAD-EX, at the University of Tokushima (UT) in Japan, and the other is the introductory design and manufacturing class, 2.007, at the Massachusetts Institute of Technology (MIT) in the USA. Comparing these two classes conducted in two difference countries, this paper discusses how we created learning environments that engage students in a variety of design-related activities.


Author(s):  
A. N. Bozhko

Computer-aided design of assembly processes (Computer aided assembly planning, CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. Intensive research on CAAP has been underway since the 1980s. Meanwhile, specialized design systems were created to provide synthesis of assembly plans and product decompositions into assembly units. Such systems as ASPE, RAPID, XAP / 1, FLAPS, Archimedes, PRELEIDES, HAP, etc. can be given, as an example. These experimental developments did not get widespread use in industry, since they are based on the models of products with limited adequacy and require an expert’s active involvement in preparing initial information. The design tools for the state-of-the-art full-featured CAD/CAM systems (Siemens NX, Dassault CATIA and PTC Creo Elements / Pro), which are designed to provide CAAP, mainly take into account the geometric constraints that the design imposes on design solutions. These systems often synthesize technologically incorrect assembly sequences in which known technological heuristics are violated, for example orderliness in accuracy, consistency with the system of dimension chains, etc.An AssemBL software application package has been developed for a structured analysis of products and a synthesis of assembly plans and decompositions. The AssemBL uses a hyper-graph model of a product that correctly describes coherent and sequential assembly operations and processes. In terms of the hyper-graph model, an assembly operation is described as shrinkage of edge, an assembly plan is a sequence of shrinkages that converts a hyper-graph into the point, and a decomposition of product into assembly units is a hyper-graph partition into sub-graphs.The AssemBL solves the problem of minimizing the number of direct checks for geometric solvability when assembling complex products. This task is posed as a plus-sum two-person game of bicoloured brushing of an ordered set. In the paradigm of this model, the brushing operation is to check a certain structured fragment for solvability by collision detection methods. A rational brushing strategy minimizes the number of such checks.The package is integrated into the Siemens NX 10.0 computer-aided design system. This solution allowed us to combine specialized AssemBL tools with a developed toolkit of one of the most powerful and popular integrated CAD/CAM /CAE systems.


2011 ◽  
Vol 109 ◽  
pp. 711-714
Author(s):  
Ying Jiang ◽  
Jie Liu

Secondary develop system can realize design automation of the common parts, so that software system can automatically inquire the chart and get data, then this could really release design personnel and improve the design efficiency. By secondary develop system of stirred tank users can respectively carry on the design according to their own needs. So secondary develop system has the function of automatic generation graphics, and can generate CAD drawings complying with the design requirement, so it reflected the intelligent performance of the design system. Secondary develop system is able to complete the automatic design of common parts, and can greatly improve the quality and efficiency of design, so it has very important use value. This design realizes the function of automatic graphics generation of transmission of stirred tank, and can generate structure design of common belt wheel.


2016 ◽  
Vol 44 ◽  
pp. 1660208
Author(s):  
Nikolaos Gazis ◽  
David McGinnis ◽  
Stephen Molloy ◽  
Eugene Tanke ◽  
Carl-Johan Hardh ◽  
...  

The European Spallation Source (ESS), currently under construction in Lund, Sweden, will be the world’s most powerful source of neutrons. The goal is to deliver neutrons to users in 2019 and reach full power sometime in the middle of the following decade. One of the key issues for ESS is to develop a strategy, along with the proper innovative tools, to efficiently communicate and smoothly collaborate between divisions and groups inside ESS and with its outside collaborators, so-called In-Kind Contributors (IKC). Technical requirements related to the scope to be delivered are among the most important technical information to be exchanged. This information exchange is facilitated by using a commercial requirements management database that is accessible through the web. The physics multidisciplinary needs are linked with the engineering integration through LinacLego, which is a tool that provides all updated lattice data for the accelerator. The lattice information is then gathered and utilized to control the physical positioning of the mechanical engineering components for the accelerator. The precision for this operation is provided by a dedicated mechanical design skeleton in a Computer Aided Design (CAD) environment. Finally, the realization of all these steps is supervised in detail and continuously evaluated. In this way the required ESS machine design can be delivered, both in terms of the engineering and the physics aspects.


Author(s):  
А.И. Гайкович ◽  
С.И. Лукин ◽  
О.Я. Тимофеев

Процесс создания проекта судна или корабля рассматривается как преобразование информации, содержащейся в техническом задании на проектирование, нормативных документах и знаниях проектанта, в информацию, объем которой позволяет реализовать проект. Проектирование может быть представлено как поиск решения в пространстве задач. Построение цепочки последовательно решаемых задач составляет методику проектирования. Проектные задачи могут быть разбиты на две группы. Первая группа ‒ это полностью формализуемые задачи, для решения которых есть известные алгоритмы. Например, построение теоретического чертежа по известным главным размерениям и коэффициентам формы. Ко второй группе задач можно отнести трудно формализуемые или неформализуемые задачи. Например, к задачам этого типа можно отнести разработку общего расположения корабля. Важнейшим инструментом проектирования современного корабля или судна является система ав­томатизированного проектирования (САПР). Решение САПР задач первой группы не представляет проблемы. Введение в состав САПР задач второй группы подразумевает разработку специального ма­тематического аппарата, базой для которого, которым является искусственный интеллект, использующий теорию нечетких множеств. Однако, настройка искусственных нейронных сетей, создание шкал для функций принадлежности элементов нечетких множеств и функций предпочтений лица принимающего решения, требует участие человека. Таким образом, указанные элементы искусственного интеллекта фиксируют качества проек­танта как специалиста и создают его виртуальный портрет. The process of design a project of a ship is considered as the transformation of information contained in the design specification, regulatory documents and the designer's knowledge into information, the volume of which allows the project to be implemented. Designing can be represented as a search for a solution in the space of problems. The construction of a chain of sequentially solved tasks constitutes the design methodology. Design problems can be divided into two groups. The first group is completely formalizable tasks, for the solution of which there are known algorithms. For example, the construction of ship's surface by known main dimensions and shape coefficients. Tasks of the second group may in­clude those which are difficult to formalize or non-formalizable. For example, tasks of this type can include develop­ment of general arrangement of a ship. The most important design tool of a modern ship or vessel is a computer-aided design system (CAD). The solu­tion of CAD problems of the first group is not a problem. Introduction of tasks of the second group into CAD implies development of a special mathematical apparatus, the basis for which is artificial intelligence, which uses the theory of fuzzy sets. However, the adjustment of artificial neural networks, the creation of scales for membership functions of fuzzy sets elements and functions of preferences of decision maker, requires human participation. Thus, the above elements of artificial intelligence fix the qualities of the designer as a specialist and create his virtual portrait.


Author(s):  
Т. В. Самодурова ◽  
Н. Ю. Алимова ◽  
О. А. Волокитина ◽  
О. В. Гладышева

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.


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