scholarly journals A Design Approach Of Mechanical Assemblies Based On MBSE And CAD Models Interoperability

2021 ◽  
Author(s):  
Rihab Brahmi ◽  
Imen Belhadj ◽  
Moncef Hammadi ◽  
Nizar Aifaoui ◽  
Jean-Yves Choley
Keyword(s):  
Computer Aided Design ◽  
Technological Development ◽  
Collaborative Work ◽  
Point Of View ◽  
Mechanical Assemblies ◽  
Development Cycle ◽  
Complexity Problem ◽  
Design Activities ◽  
Cad Models ◽  
Aided Design

Abstract The technological development of the last decades have been able to push human to develop their needs, so a way to new demands were opened and this can lead to a complexity problem. Thereby, a good interoperability between the product design activities can lead to the possibility of ensuring a promising satisfaction to all requirements. However, the major problem is the enormous discontinuity between them. Indeed, each one treats the product from its point of view without recourse to the requirements defined by others. This paper is interested in the collaborative work that brings together the system engineer, who deals with the system from a global view, and the designer, who is a specialist in the detailed design, in order to validate requirements. A new methodology has been proposed to define the role of each one in the design process. This methodology focuses on the product development cycle from the analysis of needs to the validation phase. This obviously requires interoperability between the two domains of Model Based System Engineering (MBSE) and Computer Aided Design (CAD). Based on a pedal bicycle case study which is an industrial mechatronic product, the proposed methodology will be illustrated for validation and highlighting its advantages and limitations.

Effects of Immersion on Virtual Reality Prototype Design Reviews of Mechanical Assemblies

2018 ◽  
Author(s):  
Luis de Casenave ◽  
José E. Lugo
Keyword(s):  
Computer Aided Design ◽  
Virtual Prototype ◽  
Point Of View ◽  
Human Computer Interface ◽  
Design Decisions ◽  
Mechanical Assemblies ◽  
Accurate Design ◽  
Virtual Prototypes ◽  
Aided Design ◽  
Prototype Design

The proficiency of Computer Aided Design (CAD) to save, communicate and render realistic virtual prototypes allows for easier communication and review of proposed design decisions via design reviews. However, the use of virtual prototypes is limited by the realism of the human computer interface. This paper builds on previous research investigating if increasing the realism of input and output interactions between subjects and virtual prototypes will affect user’s ability to analyze an assembly for errors. For this end, two experiments were conducted which asked participants to perform design reviews on assembly models and identify errors in the assembly. The first experiment tested virtual prototype output display factors through subject point of view movement and virtual prototype rotation. The second experiment tested human input factors using different controller setups. It is expected the more realistic virtual prototype rendering and controller input experience will result in more accurate design reviews.

Examining the Effects of CAD Model Attributes on Alteration Time and Procedure

2010 ◽  
Author(s):  
Michael D. Johnson ◽  
Ram Prasad Diwakaran
Keyword(s):  
Product Development ◽  
Cycle Time ◽  
Computer Aided Design ◽  
Development Process ◽  
Original Model ◽  
Modern Computer ◽  
Development Cycle ◽  
Cad Models ◽  
Complex Features ◽  
Aided Design

Modern computer-aided design (CAD) systems have significantly contributed to product development efficiency and cycle time reduction. CAD models can undergo several iterations through the development process; the use of CAD tools allows for these models to be quickly altered during these iterations. Altering existing CAD models can also reduce product development cycle-time by allowing for variants of these designs to be created quickly. These benefits require the reuse of CAD models to be quick and intuitive. This work examines the effects of several original and altered model variables (both attributes and derived quantities) and the perception of the original model on the speed with which the models were altered. Models created and altered using the SolidWorks and Pro|Engineer CAD platforms are examined and compared. It is shown that CAD models with fewer, complex features are altered more quickly. Models deemed as properly conveying design intent are also altered more quickly. Models perceived as having an intuitive feature order have a higher percentage of features being retained, but feature retention does not significantly affect alteration time. It is also shown that in the absence of incentives, improper modeling procedures are not corrected and increase during alteration.

scholarly journals Edge Models with the CAD Software: Creating a New Context for Mathematics in Elementary School

2021 ◽  
Author(s):  
Felicitas Pielsticker ◽  
Ingo Witzke ◽  
Amelie Vogler
Keyword(s):  
Elementary Schools ◽  
Digital Media ◽  
Computer Aided Design ◽  
Subjective Experience ◽  
Fourth Graders ◽  
Point Of View ◽  
Toulmin Model ◽  
Geometric Objects ◽  
Design Software ◽  
Aided Design

AbstractDigital media have become increasingly important in recent years and can offer new possibilities for mathematics education in elementary schools. From our point of view, geometry and geometric objects seem to be suitable for the use of computer-aided design software in mathematics classes. Based on the example of Tinkercad, the use of CAD software — a new and challenging context in elementary schools — is discussed within the approach of domains of subjective experience and the Toulmin model. An empirical study examined the influence of Tinkercad on fourth-graders’ development of a model of a geometric solid and related reasoning processes in mathematics classes.

scholarly journals An isogeometric b-rep mortar-based mapping method for non-matching grids in fluid-structure interaction

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Andreas Apostolatos ◽  
Altuğ Emiroğlu ◽  
Shahrokh Shayegan ◽  
Fabien Péan ◽  
Kai-Uwe Bletzinger ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fluid Structure Interaction ◽  
Mapping Method ◽  
Boundary Representation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Discrete Surface ◽  
Cad Models ◽  
Volume Method ◽  
Aided Design

AbstractIn this study the isogeometric B-Rep mortar-based mapping method for geometry models stemming directly from Computer-Aided Design (CAD) is systematically augmented and applied to partitioned Fluid-Structure Interaction (FSI) simulations. Thus, the newly proposed methodology is applied to geometries described by their Boundary Representation (B-Rep) in terms of trimmed multipatch Non-Uniform Rational B-Spline (NURBS) discretizations as standard in modern CAD. The proposed isogeometric B-Rep mortar-based mapping method is herein extended for the transformation of fields between a B-Rep model and a low order discrete surface representation of the geometry which typically results when the Finite Volume Method (FVM) or the Finite Element Method (FEM) are employed. This enables the transformation of such fields as tractions and displacements along the FSI interface when Isogeometric B-Rep Analysis (IBRA) is used for the structural discretization and the FVM is used for the fluid discretization. The latter allows for diverse discretization schemes between the structural and the fluid Boundary Value Problem (BVP), taking into consideration the special properties of each BVP separately while the constraints along the FSI interface are satisfied in an iterative manner within partitioned FSI. The proposed methodology can be exploited in FSI problems with an IBRA structural discretization or to FSI problems with a standard FEM structural discretization in the frame of the Exact Coupling Layer (ECL) where the interface fields are smoothed using the underlying B-Rep parametrization, thus taking advantage of the smoothness that the NURBS basis functions offer. All new developments are systematically investigated and demonstrated by FSI problems with lightweight structures whereby the underlying geometric parametrizations are directly taken from real-world CAD models, thus extending IBRA into coupled problems of the FSI type.

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

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.

scholarly journals Characterisation of the Filler Fraction in CAD/CAM Resin-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1986
Author(s):  
Andreas Koenig ◽  
Julius Schmidtke ◽  
Leonie Schmohl ◽  
Sibylle Schneider-Feyrer ◽  
Martin Rosentritt ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Point Of View ◽  
Specific Information ◽  
Dental Resin ◽  
X Ray ◽  
Computer Aided ◽  
Cad Cam ◽  
Filler Fraction ◽  
The Individual ◽  
Aided Design

The performance of dental resin-based composites (RBCs) heavily depends on the characteristic properties of the individual filler fraction. As specific information regarding the properties of the filler fraction is often missing, the current study aims to characterize the filler fractions of several contemporary computer-aided design/computer-aided manufacturing (CAD/CAM) RBCs from a material science point of view. The filler fractions of seven commercially available CAD/CAM RBCs featuring different translucency variants were analysed using Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), Micro-X-ray Computed Tomography (µXCT), Thermogravimetric Analysis (TG) and X-ray Diffractometry (XRD). All CAD/CAM RBCs investigated included midifill hybrid type filler fractions, and the size of the individual particles was clearly larger than the individual specifications of the manufacturer. The fillers in Shofu Block HC featured a sphericity of ≈0.8, while it was <0.7 in all other RBCs. All RBCs featured only X-ray amorphous phases. However, in Lava Ultimate, zircon crystals with low crystallinity were detected. In some CAD/CAM RBCs, inhomogeneities (X-ray opaque fillers or pores) with a size <80 µm were identified, but the effects were minor in relation to the total volume (<0.01 vol.%). The characteristic parameters of the filler fraction in RBCs are essential for the interpretation of the individual material’s mechanical and optical properties.

scholarly journals DECOMPOSITION ALGORITHM FOR TOOL PATH PLANNING FOR WIRE-ARC ADDITIVE MANUFACTURING

2018 ◽  
Vol Vol.18 (No.1) ◽  
pp. 96-107 ◽  
Author(s):  
Lam NGUYEN ◽  
Johannes BUHL ◽  
Markus BAMBACH
Keyword(s):  
Additive Manufacturing ◽  
Path Planning ◽  
Computer Aided Design ◽  
Tool Path ◽  
Heuristic Method ◽  
Support Material ◽  
Build Time ◽  
Cad Models ◽  
Aided Design ◽  
Wire Arc Additive Manufacturing

Three-axis machines are limited in the production of geometrical features in powder-bed additive manufacturing processes. In case of overhangs, support material has to be added due to the nature of the process, which causes some disadvantages. Robot-based wire-arc additive manufacturing (WAAM) is able to fabricate overhangs without adding support material. Hence, build time, waste of material, and post-processing might be reduced considerably. In order to make full use of multi-axis advantages, slicing strategies are needed. To this end, the CAD (computer-aided design) model of the part to be built is first partitioned into sub-parts, and for each sub-part, an individual build direction is identified. Path planning for these sub-parts by slicing then enables to produce the parts. This study presents a heuristic method to deal with the decomposition of CAD models and build direction identification for sub-entities. The geometric data of two adjacent slices are analyzed to construct centroidal axes. These centroidal axes are used to navigate the slicing and building processes. A case study and experiments are presented to exemplify the algorithm.

scholarly journals A preliminary design study for an expander liquid oxygen turbopump

2019 ◽  
Author(s):  
C. Maeding ◽  
L. Souverein ◽  
D. Hummel ◽  
S. Koenigbauer ◽  
A. Wagner ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Performance Estimation ◽  
Liquid Oxygen ◽  
Rocket Propulsion ◽  
Thrust Chamber ◽  
Design Activities ◽  
Speed Selection ◽  
Aided Design ◽  
Structural Aspects ◽  
Turbine Drive

In the recent years, Airbus DS GmbH started a turbopump initiative to buildup fundamental capabilities in analyzing and designing turbomachinery within a German national funded program “TARES.” Turbomachinery is widely used in different rocket propulsion systems and include such parts as pumps and turbines. Turbines are used for generating power required by pumps in order to feed the propellants to the thrust chamber. The paper is dedicated to present an overview about currently ongoing conceptual design activities of turbomachinery covering the main design phases like TPA (TurboPump Assembly) layout tradeoff; rotational speed selection with respect to efficiency and cavitation; flow path design techniques including blade profiling; computer-aided design (CAD) work; and preliminary structural analyses. This paper presents the main outcome applying the established design logic to a liquid oxygen (LOx) turbomachinery. The component is designed based on a dedicated specification for an expander cycle type engine. This includes a LOx pump unit comprising inducer and impeller as well as a subsonic single stage reaction turbine. For the turbine drive, gaseous hydrogen (GH2) heated within the thrust chamber cooling circuit is used. Within this paper, a general overview about the preliminary work results of pump and turbine sizing, profiling, performance estimation as well as structural aspects is given.

A New Family of Bricard-Derived Deployable Mechanisms

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Hailin Huang ◽  
Bing Li ◽  
Jianyang Zhu ◽  
Xiaozhi Qi
Keyword(s):  
Large Volume ◽  
Computer Aided Design ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
New Family ◽  
Revolute Joints ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

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.

Automatic Coordinate Measuring Machine Inspection

1999 ◽  
Author(s):  
V. A. Albuquerque ◽  
F. W. Liou ◽  
S. Agarwal ◽  
O. R. Mitchell
Keyword(s):  
Path Planning ◽  
Computer Aided Design ◽  
Coordinate Measuring Machine ◽  
Industrial Applications ◽  
Prototype Development ◽  
Development Cycle ◽  
Inspection Process ◽  
Measuring Machine ◽  
Aided Design ◽  
Point Placement

Abstract In many industrial applications, such as product prototype development, automation of inspection process can greatly improve product quality and product development cycle, time. This paper discusses a development of a vision aided automatic inspection using Coordinate Measuring Machine (CMM). We seek to integrate the flexibility afforded by computer vision systems with the precision of numerically controlled coordinate measuring machines to achieve a fully automatic and reliable inspection of the industrial parts. The 3-D design information and part specification from computer-aided design file is used for inspection point placement and CMM path planning. The proposed system demonstrates that optimal collision-free inspection paths can be efficiently generated for geometrically complex parts consisting of multiply intersecting features. This is made possible by using iterative subdivision of surfaces for point placement coupled with, efficient 3-D collision avoidance and path planning. The paper discusses different algorithms used, and presents experimental results.

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