Computer-Aided Design/Tolerancing Integration: A Novel Tolerance Analysis Model of Assemblies With Composite Positional Defects and Deformations of Nonrigid Parts

2021 ◽  
Vol 143 (8) ◽  
Author(s):  
A. Korbi ◽  
M. Tlija ◽  
B. Louhichi
Keyword(s):  
Computer Aided Design ◽  
Tolerance Analysis ◽  
Cad Model ◽  
Analysis Model ◽  
Tolerance Zone ◽  
Manufacturing Defects ◽  
Material Condition ◽  
Computer Aided ◽  
Positional Tolerance ◽  
Aided Design

Abstract Nowadays, the tolerancing integration in computer-aided design (CAD) tools remains among the major goals of mechanical manufacturers. In the virtual product development, ideal and rigid models are used in the digital mockup (DMU). Hence, research works developed integrated CAD models for tolerance analysis, while considering manufacturing defects. However, the tolerance analysis in the case of composite positional tolerance for feature patterns, commonly used in the industry, becomes a difficult activity with the consideration of parts deformations. Thus, this paper presents a novel CAD model for the tolerance analysis considering composite positional defect of features set and nonrigid component deformations due to external mechanical loads. The modeling of rigid components with dimensional defects is established based on the numerical perturbation method. Indeed, the relationships between driving and driven dimensions are determined to obtain the configurations in maximum and least material of the CAD model. Thereafter, the geometrical deviations are modeled by face displacements. The modeling of composite positional errors is performed while respecting the feature relating position tolerance zone framework and the pattern-location tolerance zone framework constraints, as well as the maximum or least material condition. The deviations caused by nonrigid part deformations are considered by the integration of finite element results into the CAD model. The realistic configurations of the assembly are obtained after the updating of mating constraints between rigid and nonrigid parts with defects. The composite positional tolerance is analyzed with the simulation of relative motion between parts. A case study is proposed to evaluate the developed tolerancing method.

A Novel Model for the Tolerancing of Nonrigid Part Assemblies in Computer Aided Design

2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Mehdi Tlija ◽  
Anis Korbi ◽  
Borhen Louhichi ◽  
Abdelmajid Benamara
Keyword(s):  
Computer Aided Design ◽  
Tolerance Analysis ◽  
Physical Factors ◽  
Worst Case ◽  
Manufacturing Defects ◽  
Computer Aided ◽  
Aided Design ◽  
Novel Model

In the design step, the realistic modeling of the product represents an industrial requirement and a digital muck up (DMU) improvement. Thus, the tolerance integration in the computer aided design (CAD) model with the neglect of important physical factors, such as the components’ deformations during the mounting and assembly operation, causes a deviation between the numerical and the realistic models. In this regard, this paper presents a new model for the tolerance analysis of CAD assemblies based on the consideration of both manufacturing defects and deformations. The dimensional and geometrical tolerances are considered by the determination of assemblies’ configurations with defects based on the worst case tolerancing. The finite elements (FEs) simulation is realized with realistic models. An algorithm for updating the realistic mating constraints, between rigid and nonrigid parts, is developed. The case study of an assembly with planar and cylindrical joints is presented.

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.

Laser Additive Manufacturing

3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Cad Model ◽  
Laser Additive Manufacturing ◽  
Computer Aided ◽  
Manufacturing Technologies ◽  
Aided Design

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.

Computer aided design (CAD) model search and retrieval using frequency domain file conversion

2020 ◽  
Vol 36 ◽  
pp. 101554
Author(s):  
Wenjin Li ◽  
Gary Mac ◽  
Nektarios Georgios Tsoutsos ◽  
Nikhil Gupta ◽  
Ramesh Karri
Keyword(s):  
Frequency Domain ◽  
Computer Aided Design ◽  
Cad Model ◽  
Model Search ◽  
Computer Aided ◽  
Aided Design ◽  
Search And Retrieval

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.

Curvature Estimation for Metrology of Non-Rigid Parts

2013 ◽  
Author(s):  
Ali Aidibe ◽  
Souheil-Antoine Tahan
Keyword(s):  
Residual Stresses ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Cad Model ◽  
New Approach ◽  
Profile Deviation ◽  
Defect Area ◽  
Computer Aided ◽  
Curvature Estimation ◽  
Aided Design

At the end of the manufacturing process, engineers need to know if a manufactured part fits its computer-aided design (CAD) model and how is the amplitude of inherent variation of manufacturing process. Non-rigid parts, at free state condition, may have a significant different form than their CAD model due to gravity loads; residual stresses induced distortion and/or assembly load. Today, a complicated and expensive specialized fixture is needed to conform these parts. To tackle the above challenges, we present in this paper a new approach for metrology of fixtureless non-rigid parts. This approach combines the curvature properties of manufactured parts with the extreme value statistic test as identification method to distinguish profile deviation due to the manufacturing process from part’s deformation due to the flexibility of the part and to determine whether the tolerance fits the CAD model or no. This approach is tested on simulated typical industrial sheet metal giving satisfying results in terms of percentage of errors in defect area and in peak profile deviation estimated.

Computer Aided Design of Implant Based Dental Restorations

2008 ◽  
Author(s):  
Ming C. Leu ◽  
Amit Gawate
Keyword(s):  
Computer Aided Design ◽  
Patient Specific ◽  
Facial Features ◽  
Cad Model ◽  
Dental Restorations ◽  
Computer Aided ◽  
Cad Cam ◽  
Scan Data ◽  
Aided Design ◽  
Cam Systems

Implant based dental restorations have many advantages over standard removable dentures because using implants can prevent the loss of jawbones, help restore facial features, and enable the patients to get firm bites. A critical step in this kind of restorations is the fabrication of the dental bar on which the denture sits. A dental bar is patient-specific because each patient’s jawbone is unique and the device needs to be conforming to the patient’s gingival surface. The design of a dental bar is crucial to the success of dental restorations. Traditionally, designing a dental bar is a lengthy and laborious process and requires high levels of craftsmanship. There have been attempts to develop CAD/CAM systems towards automating design and fabrication of dental restorations. However, currently available commercial CAD/CAM systems are only capable of making crowns, bridges, copings, onlays and veneers, and they are not capable of making dental restorations involving multiple teeth. The present paper describes a method for computer aided design of a dental bar used in implant based dental restorations. The method starts with a set of digital scan data representing the patient’s gingival surface and generates a CAD model of a dental bar that is ready for fabrication of a physical dental bar.

scholarly journals The Application of Computer Aided Design as Tool for Building User-Centered Design in Consumer Ceramics’ Product Development

2012 ◽  
Vol 2 (2) ◽  
pp. 30-42 ◽  
Author(s):  
Olalere Folasayo Enoch ◽  
Ab Aziz Bin Shuaib ◽  
Ramli bin Ismail
Keyword(s):  
Product Development ◽  
Computer Aided Design ◽  
New Product ◽  
Consumer Products ◽  
Cad Model ◽  
User Centered Design ◽  
User Centred Design ◽  
Computer Aided ◽  
Aided Design ◽  
Functional Ceramic

This paper investigates the knowledge regarding how user-centre design can be built in ceramic consumer products. The paper gives the general overview of ceramics, computer-aided design and its application in ceramic product development. It also illuminates on product emotion, its influence on consumers’ behaviour and how it can be integrated into new product conceptualization. Furthermore, the paper analysed the systematic approach in building user-centred design in new product and also reveals how CAD can be used to achieve a user-centred design. In order to test the viability of CAD in achieving user-centred design, a study was performed where a CAD-model of a multi-functional ceramic pot was created and a questionnaire with the image (CAD model) and eight emotions was given to participants so as to know their emotional responses toward the product. The result from the study reveals the viability of computer aided design as tool for building user-centred design in consumer ceramics’ product development.

Status, Comparison, and Issues of Computer-Aided Design Model Data Exchange Methods Based on Standardized Neutral Files and Web Ontology Language File

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Yuchu Qin ◽  
Wenlong Lu ◽  
Qunfen Qi ◽  
Xiaojun Liu ◽  
Yanru Zhong ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Data Exchange ◽  
Cad Model ◽  
Web Ontology Language ◽  
Model Data ◽  
Cad Systems ◽  
Ontology Language ◽  
Depth Analysis ◽  
Computer Aided ◽  
Aided Design

Exchanging computer-aided design (CAD) model data among heterogeneous CAD systems is indispensable for collaborative product development. Currently, the industry mainly uses the standardized neutral files-based methods to implement such exchange. While at the same time, the application of web ontology language (OWL) file and underlying semantic web technologies in CAD model data exchange is gaining importance and popularity within the academia. The coexistence of different types of methods has generated a series of controversies and questions within the industry and the academia. Yet, can the neutral files-based exchange methods completely implement model data exchange among heterogeneous CAD systems? What challenges have been addressed to date by the developed CAD model data exchange standards? Why OWL has been introduced to CAD model data exchange? Does CAD model data exchange really need OWL? Are there any issues in existing neutral files-based exchange methods and OWL file-based exchange methods need to be addressed in future studies? This paper proposes to conduct a study of the standardized neutral files-based exchange methods and OWL file-based exchange methods. An in-depth analysis of the widely used standard for the exchange of product model data (STEP) method and the newly emerging OWL methods is first provided. Then, the paper makes a detailed comparison between these two types of methods based on this analysis. Finally, some issues in the two types of methods that need to be addressed in the future are discussed.

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