Development of the New Drafting and Computer Aided Design Standards for Mechanical Engineering Program

Author(s):  
Sung-Hwan Joo

The paper provides the method to develop the drafting and CAD standards for mechanical engineering program based on the systemic approach. The drafting has been used since the early stage of engineering. Lots of drafting technique has been developed and standardized. Recently, Computer Aided Design (CAD) software has been used widely in academia and industries too. Because of these reasons, every mechanical engineering program offers Drafting and CAD courses to its students. Some programs even have their own Drafting and CAD standards. However, it is not easy to develop the Drafting and CAD standard for whole program. It needs a careful plan to develop the standards. It needs to meet the certain requirements. Those requirements are 1) It needs to meet ASME Y14/ANSI Y14 standard as much as possible, 2) Students should be able to understand the standards and apply the rules to their own drawing and CAD models, 3) Any instructors should be able to give the proper feedback to students about their drawing using the standards, 4) Graduating students should be able to adopt the standard of their company easily. To meet these requirements, some preliminary work must be done. 1) Understanding of ASME Y14 is needed, 2) Expertise of one or more CAD software packages is required, 3) Students’ level of understanding the ASME Y14 standards needs to be measured, 4) Feedback from industries is required. Each steps of development of Drafting and CAD standards are explained using real example of students work.

Author(s):  
R. F. Hamade

Having observed mechanical engineering seniors at the American University of Beirut (AUB) go about learning computer-aided design (CAD) in a formal setting, the instructors always wondered why some students acquire CAD skills with relative ease while some others seem to struggle. For this reason, a methodical study was launched in order to address this issue. Hence, and in order to “study the students as they learn” was accomplished by following 74 mechanical engineering seniors (it took three academic years including AY 2008–09 in order to have access to this relatively large number of trainees) as they went through a semester-long formal training on a commercial computer-aided design (CAD) package (Pro/Engineer, version Wildfire). The study methodically explored the trainees’: (1) technical background, (2) behavioral attributes (willingness-to-learn), and their (3) learning preferences. Investigating the technical background included quantifying the trainees’ relevant technical competencies specifically: basic math foundation, advanced math foundation, CAD-related mathematical foundation, computer science and engineering foundation, methodologies related to CAD, graphics foundation, and mechanical design foundation. Determining the trainees’ behavioral attributes included exploring their initial attitude towards learning of CAD, perception and imagination, and gauging their actual behavior (practice and CAD skills learned) throughout the training. Trainees’ learning styles were determined according to the index of learning styles, ILS [1]. Furthermore, and in order to assess the trainees’ progress in CAD knowledge acquisition, competency tests were conducted at four intervals throughout the semester-long study (2, 4, 7, and 12 weeks). The assessment involved hands-on building of CAD test parts of comparable complexity. At the conclusion of the study, statistical methods were used to correlate the trainees’ attributes with their monitored performance. Only a fraction (17 out of a class of 74 trainees or about one in four) of the trainees were found to fit the “star CAD trainee” mold which was defined in this study as someone who is fast on the tube as well as perceptive enough to be see through the procedure of building progressively more sophisticated CAD models. A profile of this “star CAD trainee” character emerges as an individual who is technically competent and perceptive, with personal drive and positive attitude, and who possesses active, sensor, sequential and visualizing learning styles.


2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.


2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Hailin Huang ◽  
Bing Li ◽  
Jianyang Zhu ◽  
Xiaozhi Qi

This paper proposes a new family of single degree of freedom (DOF) deployable mechanisms derived from the threefold-symmetric deployable Bricard mechanism. The mobility and geometry of original threefold-symmetric deployable Bricard mechanism is first described, from the mobility characterstic of this mechanism, we show that three alternate revolute joints can be replaced by a class of single DOF deployable mechanisms without changing the single mobility characteristic of the resultant mechanisms, therefore leading to a new family of Bricard-derived deployable mechanisms. The computer-aided design (CAD) models are used to demonstrate these derived novel mechanisms. All these mechanisms can be used as the basic modules for constructing large volume deployable mechanisms.


2020 ◽  
Vol 32 (5) ◽  
pp. 691-705
Author(s):  
Nazanin Ansari ◽  
Sybille Krzywinski

PurposeThis paper aims to introduce a process chain spanning from scanned data to computer-aided engineering and further required simulations up to the subsequent production. This approach has the potential to reduce production costs and accelerate the procedure.Design/methodology/approachA parametric computer-aided design (CAD) model of the flyer wearing a wingsuit is created enabling easy changes in its posture and the wingsuit geometry. The objective is to track the influence of geometry changes in a timely manner for following simulation scenarios.FindingsAt the final stage, the two-dimensional (2D) pattern cuts were derived from the developed three-dimensional (3D) wingsuit, and the results were compared with the conventional ones used in the first stages of the wingsuit development.Originality/valueProposing a virtual development process chain is challenging; apart from the fact that the CAD construction of a wingsuit flyer – in itself posing a complicated task – is required at a very early stage of the procedure.


From time to time the Royal Society organizes meetings for the discussion of some new development in engineering and applied science. It seemed possible to the organizers of this meeting that it would be profitable to bring together workers in industry and in the universities to discuss some aspect of computer-aided design. As you will see we have chosen the application of computer aids to mechanical engineering design and manufacture. This restriction to mechanical engineering was deliberate, partly because the application of computer aids to mechanical engineering design is somewhat behind similar activities in electrical and civil engineering. Another reason is that the development of such applications has reached a particularly interesting stage, and it is now perhaps appropriate to review progress and to discuss the directions in which future research should proceed. Although some examples of computer-aided design in mechanical engineering can be found from the earliest days of computing, the development really started in the late fifties with early experiments in the use of graphic displays and with the introduction of multi-access computing. Some may date the beginning of the developments which we are going to discuss today, from the work at M. I. T. on automated programmed drawing started in 1958. This has led to a concentration of effort on graphics and computer-aided drafting. Much research has been done on the mathematical description of curves, surfaces and volumes in a form suitable for engineering design. Work has been done on the automatic dimensioning of drawings, hidden line removal, the prob­lems of lofting, etc.


Author(s):  
Aditya Balu ◽  
Sambit Ghadai ◽  
Soumik Sarkar ◽  
Adarsh Krishnamurthy

Abstract Computer-aided Design for Manufacturing (DFM) systems play an essential role in reducing the time taken for product development by providing manufacturability feedback to the designer before the manufacturing phase. Traditionally, DFM rules are hand-crafted and used to accelerate the engineering product design process by integrating manufacturability analysis during design. Recently, the feasibility of using a machine learning-based DFM tool in intelligently applying the DFM rules have been studied. These tools use a voxelized representation of the design and then use a 3D-Convolutional Neural Network (3D-CNN), to provide manufacturability feedback. Although these frameworks work effectively, there are some limitations to the voxelized representation of the design. In this paper, we introduce a new representation of the computer-aided design (CAD) model using orthogonal distance fields (ODF). We provide a GPU-accelerated algorithm to convert standard boundary representation (B-rep) CAD models into ODF representation. Using the ODF representation, we build a machine learning framework, similar to earlier approaches, to create a machine learning-based DFM system to provide manufacturability feedback. As proof of concept, we apply this framework to assess the manufacturability of drilled holes. The framework has an accuracy of more than 84% correctly classifying the manufacturable and non-manufacturable models using the new representation.


Author(s):  
Hamza Arshad ◽  
Vrushank Phadnis ◽  
Alison Olechowski

Abstract We present the results of an experiment investigating two different modes of collaboration on a series of computer-aided design (CAD) tasks. Inspired by the pair programming literature, we anticipate that partners working in a fully synchronous collaborative CAD environment will achieve different levels of quality in CAD models depending on their mode of collaboration — one in which the pair is free to work in parallel, and another where the pair must coordinate to share one control. We found that a shared CAD control led to significantly better overall CAD quality than parallel CAD control. In addition, the shared control mode led to more complete and consistent CAD models, as well as the tendency for participants to follow instructions to correctly replicate features for the design task. As is predicted in the literature, a trade-off relationship (albeit weak) between quality and speed via the parallel collaboration was found. In contrast, the shared control mode shows no clear relationship between speed and quality. Collaborative CAD is increasingly seen as an appealing tool for modern product design teams. This study suggests that the benefits of this tool are not solely the effect of the tool itself, but result from the collaboration style of the designers using the tool.


Author(s):  
David Veisz ◽  
Essam Z. Namouz ◽  
Shraddha Joshi ◽  
Joshua D Summers

AbstractThis paper presents a preliminary comparison between the role of computer-aided design (CAD) and sketching in engineering through a case study of a senior design project and interviews with industry and academia. The design team consisted of four senior level mechanical engineering students each with less than 1 year of professional experience are observed while completing an industry sponsored mechanical engineering capstone design project across a 17 week semester. Factors investigated include what CAD tools are used, when in the design process they are implemented, the justification for their use from the students' perspectives, the actual knowledge gained from their use, the impact on the final designed artifact, and the contributions of any sketches generated. At each design step, comparisons are made between CAD and sketching. The students implemented CAD tools at the onset of the project, generally failing to realize gains in design efficiency or effectiveness in the early conceptual phases of the design process. As the design became more concrete, the team was able to recognize clear gains in both efficiency and effectiveness through the use of computer assisted design programs. This study is augmented by interviews with novice and experienced industry users and academic instructors to align the trends observed in the case study with industry practice and educational emphasis. A disconnect in the perceived capability of CAD tools was found between novice and experienced user groups. Opinions on the importance of sketching skills differed between novice educators and novice industry professionals, suggesting that there is a change of opinion as to the importance of sketching formed when recent graduates transition from academia to industry. The results suggest that there is a need to emphasize the importance of sketching and a deeper understanding as to the true utility of CAD tools at each stage of the design process.


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