scholarly journals Development of Intertwined Infills to Improve Multi-Material Interfacial Bond Strength

2021 ◽  
Author(s):  
Irfan Mustafa ◽  
Tsz-Ho Kwok
Keyword(s):  
Computer Aided Design ◽  
Material Design ◽  
Tensile Tests ◽  
Interfacial Bond Strength ◽  
Ongoing Research ◽  
Computer Aided ◽  
Cad Models ◽  
Multiple Materials ◽  
Aided Design ◽  
Material Information

Abstract Recently the availability of various materials and ongoing research in developing advanced systems for multi-material additive manufacturing (MMAM) have opened doors for innovation in functional products. One major concern of MMAM is the strength at the interface between materials. This paper hypothesizes overlapping and interlacing materials to enhance the bonding strength. To test this hypothesis, we need a computer-aided manufacturing (CAM) tool that can process the overlapped material regions. However, existing computational tools lack key multi-material design processing features and have certain limitations in making full use of the material information, which restricts the testing of our hypothesis. Therefore, this research also develops a new MMAM slicing framework that efficiently identifies the boundaries for materials to develop different advanced features. By modifying a ray tracing technology, we develop layered depth material images (LDMI) to process the material information from computer-aided design (CAD) models for slicing and process planning. Each sample point in the LDMI has associated material and geometric properties that are used to identify the multi-material regions. Based on the material information in each slice, interlocking joint (T-Joint) and interlacing infill are generated in the regions with multiple materials. Tensile tests have been performed to verify the enhancement of mechanical properties by the use of overlapping and interlacing materials.

scholarly journals Development of Intertwined Infills to Improve Multi-Material Interfacial Bond Strength

2021 ◽  
pp. 1-10
Author(s):  
Irfan Mustafa ◽  
Tsz Ho Kwok
Keyword(s):  
Computer Aided Design ◽  
Material Design ◽  
Tensile Tests ◽  
Interfacial Bond Strength ◽  
Ongoing Research ◽  
Computer Aided ◽  
Cad Models ◽  
Multiple Materials ◽  
Aided Design ◽  
Material Information

Abstract Recently the availability of various materials and ongoing research in developing advanced systems for multi-material additive manufacturing (MMAM) have opened doors for innovation in functional products. One major concern of MMAM is the strength at the interface between materials. This paper hypothesizes overlapping and interlacing materials to enhance the bonding strength. To test this hypothesis, we need a computer-aided manufacturing (CAM) tool that can process the overlapped material regions. However, existing computational tools lack key multi-material design processing features and have certain limitations in making full use of the material information, which restricts the testing of our hypothesis. Therefore, this research also develops a new MMAM slicing framework that efficiently identifies the boundaries for materials to develop different advanced features. By modifying a ray tracing technology, we develop layered depth material images (LDMI) to process the material information from computer-aided design (CAD) models for slicing and process planning. Each sample point in the LDMI has associated material and geometric properties that are used to identify the multi-material regions. Based on the material information in each slice, interlocking joint (T-Joint) and interlacing infill are generated in the regions with multiple materials. Tensile tests have been performed to verify the enhancement of mechanical properties by the use of overlapping and interlacing materials.

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.

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.

Orthogonal Distance Fields Representation for Machine-Learning Based Manufacturability Analysis

2020 ◽  
Author(s):  
Aditya Balu ◽  
Sambit Ghadai ◽  
Soumik Sarkar ◽  
Adarsh Krishnamurthy
Keyword(s):  
Machine Learning ◽  
Computer Aided Design ◽  
Boundary Representation ◽  
Engineering Product ◽  
Distance Fields ◽  
Computer Aided ◽  
Cad Models ◽  
Product Design Process ◽  
3D Cnn ◽  
Aided Design

Abstract Computer-aided Design for Manufacturing (DFM) systems play an essential role in reducing the time taken for product development by providing manufacturability feedback to the designer before the manufacturing phase. Traditionally, DFM rules are hand-crafted and used to accelerate the engineering product design process by integrating manufacturability analysis during design. Recently, the feasibility of using a machine learning-based DFM tool in intelligently applying the DFM rules have been studied. These tools use a voxelized representation of the design and then use a 3D-Convolutional Neural Network (3D-CNN), to provide manufacturability feedback. Although these frameworks work effectively, there are some limitations to the voxelized representation of the design. In this paper, we introduce a new representation of the computer-aided design (CAD) model using orthogonal distance fields (ODF). We provide a GPU-accelerated algorithm to convert standard boundary representation (B-rep) CAD models into ODF representation. Using the ODF representation, we build a machine learning framework, similar to earlier approaches, to create a machine learning-based DFM system to provide manufacturability feedback. As proof of concept, we apply this framework to assess the manufacturability of drilled holes. The framework has an accuracy of more than 84% correctly classifying the manufacturable and non-manufacturable models using the new representation.

Paired Computer-Aided Design: The Effect of Collaboration Mode on Differences in Model Quality

2020 ◽  
Author(s):  
Hamza Arshad ◽  
Vrushank Phadnis ◽  
Alison Olechowski
Keyword(s):  
Computer Aided Design ◽  
Shared Control ◽  
Control Mode ◽  
Pair Programming ◽  
Design Teams ◽  
Model Quality ◽  
Computer Aided ◽  
Parallel Cad ◽  
Cad Models ◽  
Aided Design

Abstract We present the results of an experiment investigating two different modes of collaboration on a series of computer-aided design (CAD) tasks. Inspired by the pair programming literature, we anticipate that partners working in a fully synchronous collaborative CAD environment will achieve different levels of quality in CAD models depending on their mode of collaboration — one in which the pair is free to work in parallel, and another where the pair must coordinate to share one control. We found that a shared CAD control led to significantly better overall CAD quality than parallel CAD control. In addition, the shared control mode led to more complete and consistent CAD models, as well as the tendency for participants to follow instructions to correctly replicate features for the design task. As is predicted in the literature, a trade-off relationship (albeit weak) between quality and speed via the parallel collaboration was found. In contrast, the shared control mode shows no clear relationship between speed and quality. Collaborative CAD is increasingly seen as an appealing tool for modern product design teams. This study suggests that the benefits of this tool are not solely the effect of the tool itself, but result from the collaboration style of the designers using the tool.

Sensible Pathways for Sensorium-Gameness Integration and Embedment in Design Tools for Multi-Phase Iterative Creative Synthesis in Design and Engineering Processes

2017 ◽  
Author(s):  
Robert E. Wendrich
Keyword(s):  
User Interfaces ◽  
Computer Aided Design ◽  
Low Cost ◽  
Sensor Technology ◽  
Design Tools ◽  
Tangible User Interfaces ◽  
Ongoing Research ◽  
Computer Aided ◽  
Multi Phase ◽  
Aided Design

Current and ongoing research and experimentations in the creation, design and build of low-cost, high-value prototypes for novel and unconventional interaction devices (IxD) in combination with cyber-physical system (CPS) (i.e. hybrid design tools (HDT), blended spaces) tangible user interfaces (TUI) and use of sensor technology lead to a variety of novel interaction modalities, experiences and possibilities. In line with this research, we propose a first prototype Human Sensor Selection Tool (HSST) as a preliminary guide and guidelines for design and engineering domains. The HSST is based on and inspired by the ‘five human senses’ [1], a plethora in human body signals (e.g. proprioceptive, vestibular) and gestures (e.g. facial expression, (e-)motions) that could be integrated, translated, transformed, adapted or mimicked to enhance and enrich the interaction modalities with for example computer-aided design (CAD), computer-aided technologies (CAx), and effectively affective CPS.

Computation of Midsurface by Feature-Based Simplification–Abstraction–Decomposition

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Yogesh H. Kulkarni ◽  
Anil Sahasrabudhe ◽  
Mukund Kale
Keyword(s):  
Computer Aided Design ◽  
Real Life ◽  
Boundary Representation ◽  
Manual Task ◽  
Computer Aided ◽  
Cad Models ◽  
Feature Based ◽  
Feature Information ◽  
Plastic Parts ◽  
Aided Design

Computer-aided design (CAD) models of thin-walled solids such as sheet metal or plastic parts are often reduced dimensionally to their corresponding midsurfaces for quicker and fairly accurate results of computer-aided engineering (CAE) analysis. Computation of the midsurface is still a time-consuming and mostly, a manual task due to lack of robust and automated techniques. Most of the existing techniques work on the final shape (typically in the form of boundary representation, B-rep). Complex B-reps make it hard to detect subshapes for which the midsurface patches are computed and joined, forcing usage of hard-coded heuristic rules, developed on a case-by-case basis. Midsurface failures manifest in the form of gaps, overlaps, nonmimicking input model, etc., which can take hours or even days to correct. The research presented here proposes to address these problems by leveraging feature-information available in the modern CAD models, and by effectively using techniques like simplification, abstraction, and decomposition. In the proposed approach, first, the irrelevant features are identified and removed from the input FbCAD model to compute its simplified gross shape. Remaining features then undergo abstraction to transform into their corresponding generic Loft-equivalents, each having a profile and a guide curve. The model is then decomposed into cellular bodies and a graph is populated, with cellular bodies at the nodes and fully overlapping-surface-interfaces at the edges. The nodes are classified into midsurface-patch generating nodes (called “solid cells” or sCells) and interaction-resolving nodes (“interface cells” or iCells). In a sCell, a midsurface patch is generated either by offset or by sweeping the midcurve of the owner-Loft-feature's profile along with its guide curve. Midsurface patches are then connected in the iCells in a generic manner, thus resulting in a well-connected midsurface with minimum failures. Output midsurface is then validated topologically for correctness. At the end of this paper, real-life parts are used to demonstrate the efficacy of the proposed approach.

scholarly journals Car style-holon recognition in computer-aided design

2018 ◽  
Vol 6 (4) ◽  
pp. 719-738 ◽  
Author(s):  
Egon Ostrosi ◽  
Jean-Bernard Bluntzer ◽  
Zaifang Zhang ◽  
Josip Stjepandić
Keyword(s):  
Computer Aided Design ◽  
Characteristic Model ◽  
Multi Scale ◽  
Characteristic Lines ◽  
Computer Aided ◽  
Cad Models ◽  
Style Shift ◽  
Aided Design ◽  
Scale Design ◽  
Progressive Accumulation

Abstract Multi-scale design can presumably stimulate greater intelligence in computer-aided design (CAD). Using the style-holon concept, this paper proposes a computational approach to address multi-scale style recognition for automobiles. A style-holon is both a whole—it contains sub-styles of which it is composed—as well as a part of a broader style. In this paper, we first apply a variable precision rough set-based approach to car evaluation and ranking. Secondly, we extracted and subsequently computed the each car's characteristic lines from the CAD models. Finally, we identified style-holons using the property of a double-headed style-holon. A style-holon is necessarily included in a typical vertical arrangement with progressive accumulation and forms a nested hierarchical order called a holarchy of styles. We adopted an interactive cluster analysis to recognize style-holons. Our results demonstrate that car style depended on each brand's individual strategy: a car is a form endowed with some structural stability. The style-holon also demonstrated that the evolution of characteristic lines should preserve the property of functional homeostasis (the same functional states) as well as the property of homeorhesis (the same stable course of change). For many car companies, stable brand recognition is an important design specification. The proposed approach was used to analyse a set of car styles as well as to assist in the design of characteristic model lines. A designer can also use this approach to evaluate whether or not the strategic requirement—style alignment with the style-holon of benchmarked cars--is satisfied. Highlights A style-holon is double-headed: a part of a greater style that contains sub-styles. A car's characteristic lines preserve the properties of homeostasis and homeorhesis. The Chinese style offers a unique context to consider functionality of a whole style. Shift from functional to emotional performance demonstrated in Chinese car brands. Evaluates the strategic requirement of style alignment with the selected style-holon.

Some (Team) Assembly Required: An Analysis of Collaborative Computer-Aided Design Assembly

2021 ◽  
Author(s):  
Kathy Cheng ◽  
Alison Olechowski
Keyword(s):  
Computer Aided Design ◽  
Time Frame ◽  
Parallel Execution ◽  
Future Research ◽  
Design Teams ◽  
Calendar Time ◽  
Computer Aided ◽  
Cad Models ◽  
Single User ◽  
Aided Design

Abstract Previous efforts in the area of collaborative computer-aided design (CAD) suggest that a team of designers working synchronously in a multi-user CAD (MUCAD) environment can produce CAD models faster than a single user. Our research is the among the first to investigate assemblies in MUCAD. Due to the lack of hierarchical feature dependency in assemblies, we propose that CAD teams can optimize assembly through modularization and parallel execution. In our study, 20 participants were tasked with assembling pre-modelled CAD parts of varying complexity in teams of one, two, three or four. We analyze audio recordings, team activity, and survey responses to compare the performance of individuals and virtual collaborative teams during assembly, while working with the same MUCAD platform. This paper features a multimodal approach to analyze team trends in communication, workflow, task allocation and challenges to determine which factors are conducive to the success of a multi-user CAD team and which are detrimental. In our work, the success of a team is measured by its productivity score, which is the number of mates added by a team within a given time frame. We present evidence that teams can complete an assembly in less calendar time than a single user, but single users are more efficient based on person-hours, due to communications and coordination overheads. Surprisingly, paired contributors exhibit an assembly bonus effect. These findings represent a preliminary understanding of collaborative CAD assembly work. Our work supports the claim that collaborative assembly activities have the potential to improve the capabilities of modern product design teams, delivering products faster and at lower cost. We identify areas for future research, and highlight areas of improvement for collaborative CAD platforms and engineering design teams.

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