scholarly journals An Exploratory Study Comparing CAD Tools and Working Styles for Implementing Design Changes

Author(s):  
Vrushank Shripad Phadnis ◽  
Kevin Alfonso Leonardo ◽  
David Robert Wallace ◽  
Alison Louise Olechowski

AbstractThis paper presents the findings of a preliminary study comparing implementation of design changes using various computer-aided design (CAD) working styles. Our study compares individuals’ and pairs’ completion of a series of changes to a toy car CAD model. We discuss the results in terms of productivity and value added ratio, derived from time-based quantitative data. We also discuss qualitative findings acquired through post-study surveys. Overall, our findings suggest that pairs were less efficient than individual designers due to overheads like communication, history dependency and complex couplings within the CAD model tree. However, it is also noteworthy that within each pair the lead participant's performance was at par with individual participants. Lastly, we also discuss behaviors and patterns that emerge as unique to the synchronous collaborative environment, motivating future work.

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.


2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Muhammad Hassan ◽  
Hussain Ahmed Tariq ◽  
Muhammad Anwar ◽  
Talha Irfan Khan ◽  
Asif Israr

Abstract This paper showcases the designing, fabrication, and performance evaluation of 90-deg alpha-type Stirling engine. The diameters of the hot and cold cylinder are 50 mm and 44 mm, respectively, with a stroke length of 70 mm. The computer-aided design (CAD) model is developed by keeping in mind the ease of manufacturing, maintenance, bearing replacements, and lubrication. After fabrication, the engine is tested by heating the hot cylinder with air as a working fluid. The engine delivered peak power of 155 watts at the temperature of 1123 K and 968 K for hot and cold cylinders, respectively. This developed prototype can be commissioned with the solar parabolic concentrator in the future based on the smooth operation while delivering power.


10.6036/9505 ◽  
2021 ◽  
Vol 96 (1) ◽  
pp. 145-149
Author(s):  
XABIER GARIKANO OSINAGA ◽  
MIKEL GARMENDIA MUJIKA ◽  
ANGEL PEREZ MANSO ◽  
ENEKO SOLABERRIETA MENDEZ

Computer-aided design competency is critical for an engineering graduate starting in the world of work. Therefore, the development of this competency must be in line with professional requirements and consider the design constraints. For example, in the case of modeling, a geometrically correct model may not be sufficient if it is unable to withstand the modifications required by design changes. Therefore, we consider that training must be based on the development of this knowledge, known as strategic knowledge, and encourage its acquisition. This article describes a CAD training proposal focused on the development of strategic knowledge. Starting from the contributions of researchers, the modeling process is broken down so that it can be reproduced in the different scenarios that may be presented at the time of modeling. In order to facilitate the acquisition of this knowledge, an active learning framework has been established and specific didactic strategies have been developed for this purpose. Finally, the results of an empirical test are presented after the implementation of this proposal in which the results show a notable improvement in the experimental group in relation to the control group. Keywords: CAD modeling, teaching-learning, strategic knowledge


3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi

Laser additive manufacturing is an advanced manufacturing process for making prototypes as well as functional parts directly from the three dimensional (3D) Computer-Aided Design (CAD) model of the part and the parts are built up adding materials layer after layer, until the part is competed. Of all the additive manufacturing process, laser additive manufacturing is more favoured because of the advantages that laser offers. Laser is characterized by collimated linear beam that can be accurately controlled. This chapter brings to light, the various laser additive manufacturing technologies such as: - selective laser sintering and melting, stereolithography and laser metal deposition. Each of these laser additive manufacturing technologies are described with their merits and demerits as well as their areas of applications. Properties of some of the parts produced through these processes are also reviewed in this chapter.


Author(s):  
Brett Stone ◽  
John Salmon ◽  
Keenan Eves ◽  
Matthew Killian ◽  
Landon Wright ◽  
...  

A competition for teams of three students using a prototype multi-user computer-aided design (MUCAD) tool was held to investigate various hypotheses regarding the performance of teams in such a setting. By comparing models from the competition to the same model in a single-user CAD environment, it is seen that use of a MUCAD system can significantly increase the value-added per unit of calendar time for a modeling effort. An investigation was also made into the causes of the performance differences among the various MUCAD teams which participated in the competition. Analysis of the results shows that teams that encouraged effective forms of communication and teams whose members scored similarly on the Purdue Spatial Visualization Test: Visualization of Rotations (PSVT:R) performed better than other teams. Areas of future research in analyzing teams in MUCAD environments are suggested.


Author(s):  
Alexander Lee ◽  
James Brink ◽  
David Anderson ◽  
Karthik Ramani

Recent developments in Computer Aided Design (CAD) have drastically reduced overall design cycle time and cost. In this paper, wirePATH, a new method for rapid direct tooling, is presented. By using specialized interactive segmentation computer software and wire electrical discharge machining (wire EDM), wirePATH can reduce manufacturing time and cost for injection molds, casting patterns, and dies. Compared to other conventional-mold making methods, wirePATH can reduce fabrication time by as much as 40 to 70%. Wirepath can use a combination of wire EDM and other processes. Our method provides a new means to produce a greater variety in products by changing only portions of the tooling. Segments allow a part of a mold to be replaced to accommodate design changes and repair. WirePATH enables new applications of wire EDM to more complex shapes by bridging the gaps between CAD, our method, wire EDM and conventional manufacturing processes.


2020 ◽  
Vol 36 ◽  
pp. 101554
Author(s):  
Wenjin Li ◽  
Gary Mac ◽  
Nektarios Georgios Tsoutsos ◽  
Nikhil Gupta ◽  
Ramesh Karri

Author(s):  
Kai Xu ◽  
Tsz-Ho Kwok ◽  
Yong Chen

Shape deformation is an important issue in additive manufacturing (AM) processes such as the projection-based Stereolithography. Volumetric shrinkage and thermal cooling during the photopolymerization process combined with other factors such as the layer-constrained building process lead to complex deformation that is difficult to predict and control. In this paper, a general reverse compensation method and related computation framework are presented to reduce the shape deformation of AM fabricated parts. During the reverse compensation process, the shape deformation is calculated based on physical measurements of shape deformation. A novel method for identifying the correspondence between the deformed shape and the given nominal computer-aided design (CAD) model is presented based on added markers. Accordingly, a new CAD model based on the shape deformation and related compensation is computed. The intelligently revised CAD model by going through the same building process can result in a fabricated part that is close to the nominal CAD model. Two test cases have been designed to demonstrate the effectiveness of the presented method and the related computation framework. The shape deformation in terms of L2- and L∞-norm based on measuring the geometric errors is reduced by 40–60%.


2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Min Li ◽  
Y. F. Zhang ◽  
J. Y. H. Fuh ◽  
Z. M. Qiu

In product design, a large proportion of three-dimensional (3D) computer-aided design (CAD) models can be reused to facilitate future product development due to their similarities in function and shape. This paper presents a novel method that incorporates modeling knowledge into CAD model similarity assessment to improve the effectiveness of reuse-oriented retrieval. First, knowledge extraction is performed on archived feature-based CAD models to construct feature dependency directed acyclic graph (FDAG). Second, based on the FDAG subgraph decomposition, two useful component partitioning approaches are developed to extract simplified essential shapes and meaningful subparts from CAD models. Third, the extracted shapes and their FDAG subgraphs are indexed. Finally, the indexed shapes that are similar to user-sketched queries are retrieved to reuse, and FDAG information of the retrieved shapes is provided as redesign suggestions. Experimental results suggest that the incorporation of modeling knowledge greatly facilitates CAD model retrieval and reuse. Algorithm evaluations also show the presented method outperforms other 3D retrieval methods.


Author(s):  
Weng Tat Chan ◽  
Boyd C. Paulson

Engineering design involves the evaluation and satisfaction of a wide variety of constraints. The ability to represent and process these constraints in a computer is important for the verification of the output produced by computer-aided design programs. Constraints need not only check designs but can also be used to derive design solution s that satisfy constraints. The paper discusses how to represent the dual nature of constraints so that design consistency is maintained as the design evolves.Assumptions and rules of thumb are used frequently in design to propose initial solutions. We represent the logic behind the derivation of these assumptions as heuristic procedures and maintain the dependencies between these assumptions and their consequents as an aid to the management of design consistency. We also propose a simple scheme, involving the partitioning of the design modules, to effect design changes when constraint violations occur. An example from structural design illustrates the methodology.


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