A Digital Material Design Framework for 3D-Printed Heterogeneous Objects

2016 ◽  
Author(s):  
Pu Huang ◽  
Yongqiang Li ◽  
Yong Chen ◽  
Jun Zeng
Keyword(s):  
Material Property ◽  
3D Model ◽  
Geometric Model ◽  
Material Design ◽  
Design Stage ◽  
User Requirements ◽  
Design Framework ◽  
Property Distribution ◽  
Digital Material ◽  
Continuous Material

In the paper a digital material design framework is presented to compute multi-material distributions in three-dimensional (3D) model based on given user requirements for additive manufacturing (AM) processes. It is challenging to directly optimize digital material composition due to extremely large design space. The presented material design framework consists of three stages. In the first stage, continuous material property distribution in the geometric model is computed to achieve the desired user requirements. In the second stage, a material dithering method is developed to convert the continuous material property distribution into 3D printable digital material distribution. A tile-based material patterning method and accordingly constructed material library are presented to efficiently perform material dithering in the given 3D model. Finite element analysis (FEA) is used to evaluate the performance of the computed digital material distributions. To mimic the layer-based AM process, cubic meshes are chosen to define the geometric shape in the digital material design stage, and its resolution is set based on the capability of the selected AM process. In the third stage, slicing data is generated from the cubic mesh model and can be used in 3D printing processes. Three test cases are presented to demonstrate the capability of the digital material design framework. Both FEA-based simulation and physical experiments are performed; in addition, their results are compared to verify the tile-based material pattern library and the related material dithering method.

scholarly journals Fast 3D Rotation Estimation of Fruits Using Spheroid Models

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2232
Author(s):  
Antonio Albiol ◽  
Alberto Albiol ◽  
Carlos Sánchez de Merás
Keyword(s):  
Fruit Quality ◽  
3D Model ◽  
Geometric Model ◽  
Fruit Shape ◽  
Single Camera ◽  
Global Score ◽  
Topographic Map ◽  
Single Image ◽  
Large Effort ◽  
Fruit Surface

Automated fruit inspection using cameras involves the analysis of a collection of views of the same fruit obtained by rotating a fruit while it is transported. Conventionally, each view is analyzed independently. However, in order to get a global score of the fruit quality, it is necessary to match the defects between adjacent views to prevent counting them more than once and assert that the whole surface has been examined. To accomplish this goal, this paper estimates the 3D rotation undergone by the fruit using a single camera. A 3D model of the fruit geometry is needed to estimate the rotation. This paper proposes to model the fruit shape as a 3D spheroid. The spheroid size and pose in each view is estimated from the silhouettes of all views. Once the geometric model has been fitted, a single 3D rotation for each view transition is estimated. Once all rotations have been estimated, it is possible to use them to propagate defects to neighbor views or to even build a topographic map of the whole fruit surface, thus opening the possibility to analyze a single image (the map) instead of a collection of individual views. A large effort was made to make this method as fast as possible. Execution times are under 0.5 ms to estimate each 3D rotation on a standard I7 CPU using a single core.

A Design Framework for Mobile Collaboration

2011 ◽  
pp. 133-138 ◽  
Author(s):  
Pedro Antunes
Keyword(s):  
Design Process ◽  
Human Activities ◽  
The Other ◽  
User Requirements ◽  
Collaborative Systems ◽  
Design Framework ◽  
Work Context ◽  
Implementation Phase ◽  
Mobile Collaboration

The design framework provides general constructs identifying phenomena of interest necessary to inquire about the work context, human activities, and system functionality. The framework identifies what information may interest designers, bounding their relationships with the other stakeholders. The framework also guides the design process, identifying how user requirements may be applied during the implementation phase. The framework has been validated in several realworld design cases. Two cases will be briefly described. This research contributes to the design of mobile collaborative systems. The most significant contributions are related to artifacts and emphasize that designers shall explore the potential of artifacts to support concerted work and sensemaking activities.

A New Framework for the Accurate FE Model of Bone Tissue Based on CT Images

2010 ◽  
Vol 44-47 ◽  
pp. 1612-1616
Author(s):  
Xiao Hui Huang ◽  
Guo Qun Zhao ◽  
Wen Guang Liu ◽  
Pei Lai Liu
Keyword(s):  
Bone Tissue ◽  
Material Property ◽  
Geometric Model ◽  
Automatic Segmentation ◽  
Region Of Interest ◽  
Ct Images ◽  
Fe Model ◽  
Volume Of Interest ◽  
Smooth Operator ◽  
New Framework

The frameworks for finite element (FE) model of bone tissue available in pervious literatures, to some extent, are expert-oriented and give rise to a considerable deviation in geometric model and assignment of material property. The objective of this study is to develop a new framework to reconstruct accurate individual bone FE model based on CT images rapidly and conveniently. In image-processing, automatic segmentation of the region of interest (ROIs) improves the efficiency. The idea of enclosed volume of interest (VOI) overcomes the drawback of geometric ambiguity in Marching Cube (MC) method. Geometric model is easily obtained by a STL translator and smooth operator in home-made program. In the material property assignment, two templates for hexahedron and tetrahedron FE models, respectively, are put forth to smoothing an abrupt change of material property in the region from cortical to cancellous. K-mean algorithm is introduced to cluster material properties to improve partition performance. Finally, the new framework is demonstrated by the implementation of a femoral FE model.

A Systematic Material Design Approach to Develop Self-Lubricating Ceramic-Composite Tool Inserts for Dry Cutting Conditions

2019 ◽  
Author(s):  
Syed Sohail Akhtar
Keyword(s):  
Fracture Toughness ◽  
Thermal Properties ◽  
Volume Fraction ◽  
Mean Field ◽  
Material Design ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Design Stage ◽  
Mechanical And Thermal Properties ◽  
Dry Cutting

Abstract A systematic approach is the focus of the current work in order to design and develop ceramic composites for cutting tool inserts with a balanced combination of structural and thermal properties together with enhanced antifriction characteristics. In the material design stage, various combinations of ceramic materials and inclusions with optimum self-lubricating attributes are selected based on predictions of mechanical and thermal properties using in-house built codes. A mean-field homogenization scheme is used to predict the constitutive behavior while J-integral based fracture toughness model is used to predict the effective fracture toughness of the ceramic composites. An effective medium approximation is used to predict the potential optimum thermal properties. The current strategy incorporates thermal and structural properties of composites as a constraint on the design process together with self-lubrication property. Among various metallic and carbon-based fillers, silicon carbide (SiC) together with titanium oxide (TiO2) and graphite are found the most suitable candidate fillers in alumina (Al2O3) matrix to produce cutting inserts with best combinations of thermal, structural and tribological properties. As a validation, various combinations of Al2O3-SiC-TiO2 and Al2O3-SiC-TiO2 composites are developed in line with the designed range of filler size and volume fraction using Spark Plasma Sintering (SPS) process to complement the material design.

Design-airworthiness integration method for general aviation aircraft during early development stage

2019 ◽  
Vol 91 (7) ◽  
pp. 1067-1076
Author(s):  
Maxim Tyan ◽  
Jungwon Yoon ◽  
Nhu Van Nguyen ◽  
Jae-Woo Lee ◽  
Sangho Kim
Keyword(s):  
Design Optimization ◽  
Design Stage ◽  
Design Parameters ◽  
Design Framework ◽  
Efficient Design ◽  
Content Type ◽  
Early Design ◽  
Early Design Stage ◽  
Optimization Framework ◽  
Design Requirements

Purpose Major changes of an aircraft configuration are conducted during the early design stage. It is important to include the airworthiness regulations at this stage while there is extensive freedom for designing. The purpose of this paper is to introduce an efficient design framework that integrates airworthiness guidelines and documentation at the early design stage. Design/methodology/approach A new design and optimization process is proposed that logically includes the airworthiness regulations as design parameters and constraints by constructing a certification database. The design framework comprises requirements analysis, preliminary sizing, conceptual design synthesis and loads analysis. A design certification relation table (DCRT) describes the legal regulations in terms of parameters and values suitable for use in design optimization. Findings The developed framework has been validated and demonstrated for the design of a Federal Aviation Regulations (FAR) 23 four-seater small aircraft. The validation results show an acceptable level of accuracy to be applied during the early design stage. The total mass minimization problem has been successfully solved while satisfying all the design requirements and certification constraints specified in the DCRT. Moreover, successful compliance with FAR 23 subpart C is demonstrated. The proposed method is a useful tool for design optimization and compliance verifications during the early stages of aircraft development. Practical implications The new certification database proposed in this research makes it simpler for engineers to access a large amount of legal documentation related to airworthiness regulations and provides a link between the regulation text and actual design parameters and their bounds. Originality/value The proposed design optimization framework integrates the certification database that is built of several types of legal documents such as regulations, advisory circulars and standards. The Engineering Requirements and Guide summarizes all the documents and design requirements into a single document. The DCRT is created as a summary table that indicates the design parameters affected by a given regulation(s), the design stage at which the parameter can be evaluated and its value bounds. The introduction of the certification database into the design optimization framework significantly reduces the engineer’s load related for airworthiness regulations.

Manufacturing Feature Based Dynamic Cost Estimation for Design

2004 ◽  
Author(s):  
Harshal Patwardhan ◽  
Karthik Ramani
Keyword(s):  
Cost Estimation ◽  
Estimation Methods ◽  
Design Stage ◽  
Design Parameters ◽  
User Requirements ◽  
Geometric Information ◽  
Early Stages ◽  
Feature Based ◽  
The Cost ◽  
Manufacturing Feature

Due to the ever-increasing competition in today’s global markets, the cost of the product is rapidly emerging as one of the most crucial factors in deciding the success of the product. Decisions made during the design stage affect as much as 70–80% of the final product cost. Hence, a manufacturing cost estimation tool that can be used by the designer concurrently during the design phase will be of maximum benefit. A literature study of the available cost estimation tools suggests that a majority of these tools are meant for use in the later stages of the product development lifecycle. In the early stages of a product lifecycle, the only information that is available to the designer is related to geometry and material. Hence, the cost estimation methods that have been developed with the intent of being used in the early stages of design make use of the geometric information available at that stage of the design. Most of the earlier models that use parametric cost estimation and features technology consider the design features in their implementation. However, such models fail to consider “manufacturing based features” such as cores and undercuts. These manufacturing based features are very important in deciding the manufacturability and the cost of the part. The Engineering Cost Advisory System (ECAS) is a knowledge-based system that presents cost advice to the designer at the design stage after considering various design parameters and user requirements. Some of these design parameters can be extracted via standard Application Programming Interfaces (APIs). Moreover, ECAS uses innovative techniques of geometric reasoning and the hybrid B-rep-voxel model approach to extract manufacturing feature-based geometric information directly from the CAD input. By considering the manufacturing based features along with the design parameters, the ECAS architecture is applicable to a much wider variety of manufacturing processes. The complexity of the part, which is derived from the geometric parameters (manufacturing based and design based) and other non-geometric user requirements (e.g. quantity, material), is used to estimate the manufacturing effort involved in process specific activities. The final cost is then estimated based on this manufacturing effort and considering the hourly rates of labor and other contextual resources as well as material rates.

3D Simulation of Mechanised Excavation in Brittle Rock

2013 ◽  
Vol 353-356 ◽  
pp. 1724-1731
Author(s):  
Kai Zhao ◽  
Michele Janutolo ◽  
Guo Xing Chen
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Complex Interaction ◽  
Granitic Rocks ◽  
Design Stage ◽  
Tunnel Wall ◽  
Tunnel Support ◽  
Left Hand ◽  
Vertical Fault ◽  
Brenner Base Tunnel

During the excavation by TBM of the Aicha Exploratory Tunnel along the Brenner Base Tunnel in Italy, in hard brittle granitic rocks, an instability phenomenon occurred at chainage 6+151. The left-hand sidewall lining partially collapsed for a length of approximately 60m. This led to a stoppage of the TBM lasting about 4 months. With the reconstruction of the geological model, a sub-vertical fault, not forecast at the design stage, was identified parallel to the direction of the excavation. In this paper, a three-dimensional (3D) model, which simulates the complex interaction between the rock mass, the TBM and its system components, and the tunnel support, is presented. The model accounts for the main machine components: shields, cutterhead, grippers, pea gravel and lining. The brittle failure of a thin granite diaphragm between the fault zone and the tunnel wall is reproduced and the results are discussed in terms of failure zone and horizontal displacements.

3D Model Transformation of Waveguide Slot Array Antenna in Mechanical-Electromagnetic Analyses

2012 ◽  
Vol 562-564 ◽  
pp. 1487-1491
Author(s):  
Mei Chen ◽  
Fei Zheng ◽  
Na Li
Keyword(s):  
Model Transformation ◽  
3D Model ◽  
Geometric Model ◽  
3D Models ◽  
Transformation Method ◽  
Mechanical Analysis ◽  
Array Antenna ◽  
Waveguide Slot ◽  
Electromagnetic Model ◽  
3D Geometric Model

The mechanical errors in a mobile waveguide slot array antenna will finally influence the electromagnetic performances. Hence it is necessary to understand the relationship between them, which requires mechanical-electromagnetic analyses. The 3D models in both mechanical analysis and electromagnetic analysis are greatly different. They need a precise connection and transformation. The paper proposes an effective 3D model transformation method. From 3D geometric model to 3D mechanical model, and then to 3D electromagnetic model, the precise connection and transformation can be finished. It can be used to increase the analysis precision of a complex waveguide slot array antenna.

Improvement of Color Information in the Generation of 3D Models of Real Objects Using Range Intensity Images

2012 ◽  
Vol 523-524 ◽  
pp. 362-367
Author(s):  
Toru Takahama ◽  
Ryo Inomata ◽  
Kenji Terabayashi ◽  
Kazunori Umeda ◽  
Guy Godin
Keyword(s):  
3D Model ◽  
Geometric Model ◽  
Texture Mapping ◽  
3D Models ◽  
Correction Method ◽  
Image Sensor ◽  
Color Images ◽  
Range Image ◽  
Color Information ◽  
Intensity Image

Texture mapping on scanned objects, which is the method to map color images on a 3D geometric model measured by a range image sensor, is often used for constructing a realistic 3D model. Color images are affected by the illumination conditions. Therefore, discontinuities of seams occur when simply applying texture mapping. In this paper, we propose a method for correcting the discontinuities using a range intensity image. A range intensity image is a kind of intensity image that is related to the reflectance ratio of the measured points, simultaneously acquired with a range image using an active range sensor. The method estimates the color information that is not affected by the lighting environment using multiple color images and a range intensity image. As a result, the method is effective to construct a 3D model with seamless color images. The effectiveness of the correction method is illustrated by experiments with real-world objects.

scholarly journals Pengembangan Bahan Ajar Berbasis Instructional Approach Learning pada Mata Kuliah Kemampuan Dasar Mengajar Kimia

2022 ◽  
Vol 16 (1) ◽  
pp. 16-21
Author(s):  
Tuti Kurniati
Keyword(s):  
Social Competence ◽  
3D Model ◽  
Professional Competence ◽  
Development Stage ◽  
Student Response ◽  
Design Stage ◽  
Instructional Approach ◽  
Individual Trial ◽  
The Media ◽  
The Individual

Teachers must have competency standards in carrying out their duties. The competencies that must be possessed by professional teachers are pedagogic competence, professional competence, personal competence and social competence. In order for students to master the four competence and basic skills of teaching it is necessary to develop modul materials based on instructional approach learning. The purpose of this research is to develop modul materials. Ths research following 3D model of Thiagarajan which consists of the definition stage, the design stage and the development stage.  The result of the research shows are the validity of the material aspect is 97.5% and the media is 87.5% in valid criteria. Practicality based on the value of the student response questionnaire in the individual trial was 95.8% and the small group test wa 89.6% which was considered very practical.

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