8,785 research outputs found

    A survey on 3D CAD model quality assurance and testing

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    [EN] A new taxonomy of issues related to CAD model quality is presented, which distinguishes between explicit and procedural models. For each type of model, morphologic, syntactic, and semantic errors are characterized. The taxonomy was validated successfully when used to classify quality testing tools, which are aimed at detecting and repairing data errors that may affect the simplification, interoperability, and reusability of CAD models. The study shows that low semantic level errors that hamper simplification are reasonably covered in explicit representations, although many CAD quality testers are still unaffordable for Small and Medium Enterprises, both in terms of cost and training time. Interoperability has been reasonably solved by standards like STEP AP 203 and AP214, but model reusability is not feasible in explicit representations. Procedural representations are promising, as interactive modeling editors automatically prevent most morphologic errors derived from unsuitable modeling strategies. Interoperability problems between procedural representations are expected to decrease dramatically with STEP AP242. Higher semantic aspects of quality such as assurance of design intent, however, are hardly supported by current CAD quality testers. (C) 2016 Elsevier Ltd. All rights reserved.This work was supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund, through the ANNOTA project (Ref. TIN2013-46036-C3-1-R).González-Lluch, C.; Company, P.; Contero, M.; Camba, J.; Plumed, R. (2017). A survey on 3D CAD model quality assurance and testing. Computer-Aided Design. 83:64-79. https://doi.org/10.1016/j.cad.2016.10.003S64798

    Digital Twin for Variation Management: A General Framework and Identification of Industrial Challenges Related to the Implementation

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    Digital twins have gained a lot of interest in recent years. This paper presents a survey among researchers and engineers with expertise in variation management confirming the interest of digital twins in this area. The survey shows, however, a gap between future research interest in academia and industry, identifying a larger need in industry. This indicates that there are some barriers in the industry to overcome before the benefits of a digital twin for variation management and geometry assurance can be fully capitalized on in an industrial context. To identify those barriers and challenges, an extensive interview study with engineers from eight different companies in the manufacturing sectors was accomplished. The analysis identifies industrial challenges in the areas of system-level, simulation working process, management issues, and education. One of the main challenges is to keep the 3D models fully updated, including keeping track of changes during the product development process and also feedback changes during full production to the development engineers. This is a part of what is called the digital thread, which is also addressed in this paper

    Are we training our novices towards quality 2D profiles for 3D models?

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    In the history-based, feature-based, parametric CAD approach, 2D profile sketches are the basis for 3D models. Fully-constraining profiles is mandatory to create robust profiles. At present, neither CAD applications nor Model Quality Testing Tools usually check whether 2D profiles contain redundant constraints. Besides, our experience shows that novices tend to introduce redundant constraints. We hypothesize that 2D profiles over-constrained with redundant relations are more difficult to edit than those that avoid redundancies. In the present work―and as a first step to demonstrate this hypothesis―an experiment was conducted. Students of the subject “Graphics engineering” were taught on the creation of constrained 2D profiles. Then, they were asked two questions. On the one hand, novices had to identify and reason whether a simple given profile was fully-constrained, over-constrained or under-constrained. On the other hand, they had to identify and point out the types of the constraints. The results showed that in spite that novices received a specific training, roughly half of them failed to say if the 2D profile sketch was fully-constrained and which type of constraints it contained. Furthermore, the results of the second question revealed that more than the half of students did not recognize perpendicularity as a geometric constraint. As future work, we will try to demonstrate whether a reinforced training through simple exercises and a quick and effective feedback, will allow novices to improve the identification and removal of redundant 2D constraints when drawing 2D profile sketches (thus helping to produce robust profiles)

    Survey on Additive Manufacturing, Cloud 3D Printing and Services

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    Cloud Manufacturing (CM) is the concept of using manufacturing resources in a service oriented way over the Internet. Recent developments in Additive Manufacturing (AM) are making it possible to utilise resources ad-hoc as replacement for traditional manufacturing resources in case of spontaneous problems in the established manufacturing processes. In order to be of use in these scenarios the AM resources must adhere to a strict principle of transparency and service composition in adherence to the Cloud Computing (CC) paradigm. With this review we provide an overview over CM, AM and relevant domains as well as present the historical development of scientific research in these fields, starting from 2002. Part of this work is also a meta-review on the domain to further detail its development and structure

    Technology Trends and Opportunities for Construction Industry and Lifecycle Management

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    Master's thesis in for Offshore Technology: Industrial Asset ManagementThe purpose of the report is to highlight methods that can make it easier for the construction industry and industry in general to benefit from new technology. The report is intended as a reference to technological solutions that along with some techniques, can streamline workflow for multiple tasks in planning, design, and operation and maintenance management. The problems focused on is how to: • Simplify the procurement and tracing of documentation • Optimize building stages, design, and Life Cycle Management (LCM) • Provide interactions between disciplines and employees using different software Scientific Platform are based on literature within technology trends. Some history and trends in digital technology are presented. Definition of roles and general terms related to documentation is derived from Norsk Standard and is interpreted on this basis. The report charts the use of individual software and technical setup of digital tools within CAD-engineering (Computer Aided Design), HDS-technology (High Definition Surveying), and gaming technology. This technology combined with cloud-services to support planning, design and management of building stages. Later to support LCM of facilities and businesses' ERP-systems (Enterprise Resource Planning). Use of Robotic Process Automation (RPA) and Artificial Intelligence (AI), for document control tasks. The result of the report is that several suppliers provide services and products accessible through web. Setup and implementation will require some work and knowledge for business and organizations, but the gain largely seems to justify the use of resources for this purpose. Particularly through IOT-interactions (Internet of Things), cloud-services and free downloadable applications that may be considered as a paradigm shift related to the issues in the report. Also, presenting new platforms for engineering phases to support Building Information Modeling processes (BIM). With the use of Algorithmic Editors for encoding between computer programs without the need of data programmer expertise. To streamline workflows, reduce recreation of data, interactions between different software of various user level, and support of AI to optimize designing by adds-on for CAD-engineering (Computer Aided Design). Mobile devices like phones and tablets to support several of solutions and products presented is very accessible. It seems naturally to assume that the vast majority of people are familiar with technology related to smartphone applications for daily use. The use of resources for implementing the presented solutions have not been considered in this report. Some of the equipment presented can be interpreted as relatively expensive. Investment analysis would be sensible. The trend however, shows continues price drops and increased availability. At the same time as the user interface is being improved for both software and digital equipment. The conclusion, is that the construction industry, as well as Facility Management (FM). Within both, public, and private sector, can have much to gain using the technology and techniques presented in the report

    Testing and verification through virtual product models: A survey and look ahead

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    Functional requirements document for the Earth Observing System Data and Information System (EOSDIS) Scientific Computing Facilities (SCF) of the NASA/MSFC Earth Science and Applications Division, 1992

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    Five scientists at MSFC/ESAD have EOS SCF investigator status. Each SCF has unique tasks which require the establishment of a computing facility dedicated to accomplishing those tasks. A SCF Working Group was established at ESAD with the charter of defining the computing requirements of the individual SCFs and recommending options for meeting these requirements. The primary goal of the working group was to determine which computing needs can be satisfied using either shared resources or separate but compatible resources, and which needs require unique individual resources. The requirements investigated included CPU-intensive vector and scalar processing, visualization, data storage, connectivity, and I/O peripherals. A review of computer industry directions and a market survey of computing hardware provided information regarding important industry standards and candidate computing platforms. It was determined that the total SCF computing requirements might be most effectively met using a hierarchy consisting of shared and individual resources. This hierarchy is composed of five major system types: (1) a supercomputer class vector processor; (2) a high-end scalar multiprocessor workstation; (3) a file server; (4) a few medium- to high-end visualization workstations; and (5) several low- to medium-range personal graphics workstations. Specific recommendations for meeting the needs of each of these types are presented

    The combination of geomatic approaches and operational modal analysis to improve calibration of finite element models: a case of study in Saint Torcato church (Guimarães, Portugal)

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    This paper present a set of procedures based on laser scanning, photogrammetry (Structure from Motion) and operational modal analysis in order to obtain accurate numeric models which allows identigying architectural complications that arise in historical buildings. In addition, themethod includes tools that facilitate building-damage monitoring tasks. All of these aimed to obtain robust basis for numerical analysis of the actual behavior and monitoring task. This case study seeks to validate said methodologies, using as an example the case of Saint Torcato Church, located in Guimãres, Portugal

    Identifying and quantifying inefficiencies within industrial parametric CAD models

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    Parametric CAD software is the primary development tool for the design engineer during the product development process. However, industrial parametric CAD models are often constructed in a manner that leads to inefficiencies during subsequent product development activities. Despite the availability of Model Quality Tools (MQTs) these ‘poor’ quality models can currently only be accurately identified using time-consuming and subjective auditing from experienced users. The project aims to develop a more robust solution, using measurable part characteristics, to predict the efficiency level of these CAD files
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