Partial Encryption Based Secure Sharing of CAD Models for Cloud-Based Design

2014 ◽  
Author(s):  
Xiantao Cai ◽  
Weidong Li ◽  
Fazhi He
Keyword(s):  
Product Design ◽  
Computer Aided Design ◽  
Cad Model ◽  
Partial Encryption ◽  
Challenging Research ◽  
Collaborative Product Design ◽  
Secret Keys ◽  
Cad Models ◽  
Aided Design ◽  
Different Parts

Model security for collaborative product design in a networked environment (or called networked manufacture, grid manufacture, and cloud manufacture) is an important but also challenging research issue. In order to support collaborative product design in a secure and flexible means, a partial encryption based secure sharing method for Computer Aided Design (CAD) model is presented in this paper. Based on the above method, parts of a CAD model can be selected flexibly by users for encrypting according to different users’ requirements. The secret keys for the different parts of the CAD model can be customized to meet the requirements of users. Case studies have been developed to demonstrate the effectiveness of the proposed method.

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.

Toward Effective Mechanical Design Reuse: CAD Model Retrieval Based on General and Partial Shapes

2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Min Li ◽  
Y. F. Zhang ◽  
J. Y. H. Fuh ◽  
Z. M. Qiu
Keyword(s):  
Computer Aided Design ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Cad Model ◽  
Model Retrieval ◽  
Cad Models ◽  
Feature Based ◽  
Novel Method ◽  
Aided Design ◽  
Model Similarity

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.

A CAD Template Approach to Support Web-Based Customer Centric Product Design

2005 ◽  
Vol 5 (4) ◽  
pp. 381-387 ◽  
Author(s):  
Zahed Siddique ◽  
Karunakar Boddu
Keyword(s):  
Product Design ◽  
Design Process ◽  
Mass Customization ◽  
Computer Aided Design ◽  
Cad Model ◽  
Entire Family ◽  
Web Based ◽  
Computer Aided ◽  
Aided Design ◽  
Configurable Products

In order to provide products that can be tailored to the need of the customer, it is necessary to integrate the customer into the design process. In this paper we present a mass customization computer-aided design (CAD) framework that helps to integrate the customer into the design of user-configurable products. A template approach, which considers both modularity and scaling, is utilized to concisely represent a CAD model of the entire family. The system accepts user selections and parameters to automatically create a CAD model of the customized product in real time and then shows the model to the user. The system is implemented using PRO/ENGINEER and demonstrated through customization of bicycle frames.

Interactive Freeform Clay Modeling Supported by 3D Scanning and Robot Machining

2004 ◽  
Author(s):  
Y. Song ◽  
J. S. M. Vergeest ◽  
T. Wiegers
Keyword(s):  
Computer Aided Design ◽  
Virtual Prototyping ◽  
Cad Model ◽  
Physical Clay ◽  
3 Dimensional ◽  
Clay Model ◽  
Mesh Model ◽  
Robot Machining ◽  
Cad Models ◽  
Aided Design

Effective and efficient prototyping is always a challenging topic in design and prototyping. For this purpose, an interactive prototyping center is developed in this paper. The proposed technique is based on a synthesis of clay modeling, 3-Dimensional (3-D) scanning, robot machining and advanced geometric tools. Using 3-D scanning and reverse engineering techniques, a physical clay model is digitized to a Computer Aided Design (CAD) model by mesh representation. By advanced geometric tools, the mesh model can be changed easily following the user’s ideas. Those changes can be reflected to the clay model by robot machining. Furthermore, manual modifications on the existing clay model also can be added to the CAD model by 3-D scanning. For robot machining, a method based on 3-D scanning is used to calibrate the workpiece coordinate and the fixtures. Based on this system, virtual prototyping and physical prototyping can be achieved simultaneously. Solid or surface CAD models can be constructed directly from the mesh model after the prototyping stage. Experiments were made to demonstrate the effectiveness of the prototyping system. The possible applications in industrial product design are described as well.

Graph-Based Simplification of Feature-Based Three-Dimensional Computer-Aided Design Models for Preserving Connectivity

2015 ◽  
Vol 15 (3) ◽  
Author(s):  
Soonjo Kwon ◽  
Byung Chul Kim ◽  
Duhwan Mun ◽  
Soonhung Han
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Evaluation Metrics ◽  
Prototype System ◽  
Cad Model ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Feature Based ◽  
Aided Design

The required level of detail (LOD) of a three-dimensional computer-aided design (3D CAD) model differs according to its purpose. It is therefore important that users are able to simplify a highly complex 3D CAD model and create a low-complexity one. The simplification of a 3D CAD model requires the application of a simplification operation and evaluation metrics for the geometric elements of the 3D CAD model. The evaluation metrics are used to select those elements that should be removed. The simplification operation removes selected elements in order to simplify the 3D CAD model. In this paper, we propose the graph-based simplification of feature-based 3D CAD models using a method that preserves connectivity. First, new evaluation metrics that consider the discrimination priority among several simplification criteria are proposed. Second, a graph-based refined simplification operation that prevents the separation of a feature-based 3D CAD model into multiple volumes is proposed. Finally, we verify the proposed method by implementing a prototype system and performing simplification experiments using feature-based 3D CAD models.

Customized Encryption of Computer Aided Design Models for Collaboration in Cloud Manufacturing Environment

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Xiantao Cai ◽  
Weidong Li ◽  
Fazhi He ◽  
Xiaoxia Li
Keyword(s):  
Computer Aided Design ◽  
Cloud Manufacturing ◽  
Geometric Transformation ◽  
Cad Model ◽  
Manufacturing Environment ◽  
User Friendliness ◽  
Partial Encryption ◽  
Model Based ◽  
Computer Aided ◽  
Aided Design

Computer aided design (CAD) models reflect design goals, intentions, and functions so that they are the key intellectual properties of companies. In a Cloud manufacturing environment, how to effectively protect the sensitive feature information for a model owner while enabling the owner to flexibly share the rest of the CAD model with collaborators is an important yet challenging research issue. In this paper, an innovative partial encryption approach, which is able to represent a CAD model into the granularity of sharing information in order to address various collaboration scenarios and customized requirements from the model owner and collaborators, is presented. The approach is composed of a customized encryption algorithm for a CAD model, a key based customized authorization algorithm for collaborators to decrypt shared features in the model, and a customized geometric transformation method to support the effective protection model-based visualization of the model for collaboration. With this approach, a CAD model can be flexibly encrypted to realize partial sharing of features and safe protection of the rest of the model according to collaboration requirements. Meanwhile, during encryption and decryption, the CAD model is always manifold no matter which feature is encrypted or decrypted to ensure user friendliness, model validity, and robustness of the approach. A case study is used to verify and illustrate the effectiveness of the approach. This research is a new attempt to design a content-based and customized encryption approach applicable to CAD model-based collaboration in a Cloud manufacturing environment.

A novel method for early formal developments using computer aided design and rapid prototyping technology

2003 ◽  
Vol 217 (5) ◽  
pp. 695-698 ◽  
Author(s):  
P A Prieto ◽  
D K Wright ◽  
S F Qin
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Rapid Prototype ◽  
Physical Models ◽  
Prototype Model ◽  
Cad Model ◽  
Computer Aided ◽  
Cad Models ◽  
Novel Method ◽  
Aided Design

The paper describes a novel method for updating computer aided design (CAD) models with information taken from physical models in the early stages of design. The new approach is an image mapping based method in which an initial. CAD model is transferred to a soft rapid prototype model (RPM) made by a three-dimensional printer and sculpted in order to carry out formal developments. The RPM has a built-in contrasting three-dimensional grid composed of parallel orthogonal planes, and the initial CAD model is represented by cross-section curves corresponding to the RPM grid. The initial CAD geometry is then updated from images of the developed RPM by matching the differences between the initial CAD model and the modified RPM, making use of identical perspective transformations and viewpoints for the initial CAD model and an RPM image. Examples studied varied from a small depression on a cube face to general freeform surfaces. Compared with typical reverse engineering (RE) processes, the present approach is simpler and more direct. It is not necessary to use three-dimensional scanning or coordinate measuring devices for updating existing initial geometrical CAD models with data obtained from physical models.

scholarly journals AN UNSUPERVISED REGISTRATION OF 3D POINT CLOUDS TO 2D CAD MODEL: A CASE STUDY OF FLOOR PLAN

2020 ◽  
Vol V-2-2020 ◽  
pp. 9-13
Author(s):  
A. Alizadeh Naeini ◽  
A. Ahmad ◽  
M. M. Sheikholeslami ◽  
P. Claudio ◽  
G. Sohn
Keyword(s):  
Computer Aided Design ◽  
Point Clouds ◽  
Easy Access ◽  
Cad Model ◽  
Registration Method ◽  
Binary Images ◽  
3D Point Clouds ◽  
Cad Models ◽  
Manual Registration ◽  
Aided Design

Abstract. Thanks to the proliferation of commodity 3D devices such as HoloLens, one can have easy access to the 3D model of indoor building objects. However, this model does not match 2D available computer-aided design (CAD) models as the as-built model. To address this problem, in this study, a 3-step registration method is proposed. First, binary images, including walls and background, are generated for the 3D point cloud (PC) and the 2D CAD model. Then, 2D-to-2D corresponding pixels (CPs) are extracted based on the intersection of walls in each binary image of PC (BIPC) and binary CAD (BCAD) model. Since the 3D PC space coordinates (XYZ) of all BIPC's pixels are known, BIPC part of the 2D-to-2D CPs can be considered 3D. Lastly, the parameters of the 8-parameter affine are estimated using the 2D-to-3D CPs, which are pixel coordinates in BCAD model as well as their correspondences in the 3D PC space. Experimental results indicate the efficiency of our proposed method compared to manual registration.

scholarly journals In Silico Optimization of Femoral Fixator Position and Configuration by Parametric CAD Model

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2326
Author(s):  
Nikola Korunovic ◽  
Dragan Marinkovic ◽  
Miroslav Trajanovic ◽  
Manfred Zehn ◽  
Milorad Mitkovic ◽  
...  
Keyword(s):  
Finite Element ◽  
Structural Optimization ◽  
Computer Aided Design ◽  
Bone Fractures ◽  
Element Model ◽  
Long Bone ◽  
Design Parameters ◽  
Cad Model ◽  
Cad Models ◽  
Aided Design

Structural analysis, based on the finite element method, and structural optimization, can help surgery planning or decrease the probability of fixator failure during bone healing. Structural optimization implies the creation of many finite element model instances, usually built using a computer-aided design (CAD) model of the bone-fixator assembly. The three most important features of such CAD models are: parameterization, robustness and bidirectional associativity with finite elements (FE) models. Their significance increases with the increase in the complexity of the modeled fixator. The aim of this study was to define an automated procedure for the configuration and placement of fixators used in the treatment of long bone fractures. Automated and robust positioning of the selfdynamisable internal fixator on the femur was achieved and sensitivity analysis of fixator stress on the change of major design parameters was performed. The application of the proposed methodology is considered to be beneficial in the preparation of CAD models for automated structural optimization procedures used in long bone fixation.

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.

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