scholarly journals CAD TOOLS AND FILE FORMAT PERFORMANCE EVALUATION IN DESIGNING LATTICE STRUCTURES FOR ADDITIVE MANUFACTURING

2018 ◽  
Vol 80 (4) ◽  
Author(s):  
Abdul Hadi Azman ◽  
Frédéric Vignat ◽  
François Villeneuve
Keyword(s):  
Performance Evaluation ◽  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Data Exchange ◽  
Lattice Structure ◽  
Lattice Structures ◽  
File Size ◽  
Element Analysis ◽  
Computer Aided ◽  
Octet Truss

Additive manufacturing has opened the door to the creation of lightweight lattice structures. However, present Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) software are unsuitable for these types of structures. The objective of this research is to examine the performances of current CAD and CAE software to design lattice structures and to demonstrate their limitations and propose requirements for future developments. A performance evaluation of a case study for lattice structure designs was conducted. The criteria used for the evaluation were CAD human-machine-interface, RAM consumption, data exchange between CAD, CAE and CAM tools and finite element analysis (FEA) duration and file sizes. The CAD tool was incapable of executing a repetition function for octet-truss lattice structures of 150 x 150 x 150 mm dimensions or larger and the software stopped working. For 70 × 70 × 70 mm octet-truss lattice structure, the FEA computation file size reached 36.6 GB. The CAD file size of a 200 x 200 x 200 mm octet-truss lattice structure reached nearly 290 MB. In conclusion, this study exposes the performance inadequacy of current CAD and CAE tools and CAD file formats to design lattice structures for additive manufacturing parts.

Finite element analysis of gradient lattice structure patterns for bone implant design

2020 ◽  
Vol 11 (4) ◽  
pp. 535-545
Author(s):  
Asliah Seharing ◽  
Abdul Hadi Azman ◽  
Shahrum Abdullah
Keyword(s):  
Finite Element Analysis ◽  
Relative Density ◽  
Mechanical Behaviour ◽  
Lattice Structure ◽  
Lattice Structures ◽  
Element Analysis ◽  
Bone Implant ◽  
Content Type ◽  
Octet Truss ◽  
Structure Patterns

PurposeThe objective of this paper is to identify suitable lattice structure patterns for the design of porous bone implants manufactured using additive manufacturing.Design/methodology/approachThe study serves to compare and analyse the mechanical behaviours between cubic and octet-truss gradient lattice structures. The method used was uniaxial compression simulations using finite element analysis to identify the translational displacements.FindingsFrom the simulation results, in comparison to the cubic lattice structure, the octet-truss lattice structure showed a significant difference in mechanical behaviour. In the same design space, the translational displacement for both lattice structures increased as the relative density decreased. Apart from the relative density, the microarchitecture of the lattice structure also influenced the mechanical behaviour of the gradient lattice structure.Research limitations/implicationsGradient lattice structures are suitable for bone implant applications because of the variation of pore sizes that mimic the natural bone structures. The complex geometry that gradient lattice structures possess can be manufactured using additive manufacturing technology.Originality/valueThe results demonstrated that the cubic gradient lattice structure has the best mechanical behaviour for bone implants with appropriate relative density and pore size.

scholarly journals Design of Shoe Soles Using Lattice Structures Fabricated by Additive Manufacturing

2019 ◽  
Vol 1 (1) ◽  
pp. 719-728 ◽  
Author(s):  
Guoying Dong ◽  
Daniel Tessier ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Lattice Structure ◽  
Lattice Structures ◽  
Compression Tests ◽  
Element Analysis ◽  
Fused Deposition ◽  
Footwear Industry ◽  
Deposition Modeling ◽  
Shoe Soles

AbstractAdditive manufacturing (AM) has enabled great application potential in several major industries. The footwear industry can customize shoe soles fabricated by AM. In this paper, lattice structures are discussed. They are used to design functional shoe soles that can have controllable stiffness. Different topologies such as Diamond, Grid, X shape, and Vintiles are used to generate conformal lattice structures that can fit the curved surface of the shoe sole. Finite element analysis is conducted to investigate stress distribution in different designs. The fused deposition modeling process is used to fabricate the designed shoe soles. Finally, compression tests compare the stiffness of shoe soles with different lattice topologies. It is found that the plantar stress is highly influenced by the lattice topology. From preliminary calculations, it has been found that the shoe sole designed with the Diamond topology can reduce the maximum stress on the foot. The Vintiles lattice structure and the X shape lattice structure are stiffer than the Diamond lattice. The Grid lattice structure buckles in the experiment and is not suitable for the design.

Geometric modeling of lattice structures for additive manufacturing

2018 ◽  
Vol 24 (2) ◽  
pp. 351-360 ◽  
Author(s):  
Gianpaolo Savio ◽  
Roberto Meneghello ◽  
Gianmaria Concheri
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Geometric Modeling ◽  
Lattice Structure ◽  
Subdivision Surfaces ◽  
Lattice Structures ◽  
Content Type ◽  
Critical Issues ◽  
Surface Subdivision ◽  
Manufacturing Technologies

Purpose This paper aims to propose a consistent approach to geometric modeling of optimized lattice structures for additive manufacturing technologies. Design/methodology/approach The proposed method applies subdivision surfaces schemes to an automatically defined initial mesh model of an arbitrarily complex lattice structure. The approach has been developed for cubic cells. Considering different aspects, five subdivision schemes have been studied: Mid-Edge, an original scheme proposed by the authors, Doo–Sabin, Catmull–Clark and Bi-Quartic. A generalization to other types of cell has also been proposed. Findings The proposed approach allows to obtain consistent and smooth geometric models of optimized lattice structures, overcoming critical issues on complex models highlighted in literature, such as scalability, robustness and automation. Moreover, no sharp edge is obtained, and consequently, stress concentration is reduced, improving static and fatigue resistance of the whole structure. Originality/value An original and robust method for modeling optimized lattice structures was proposed, allowing to obtain mesh models suitable for additive manufacturing technologies. The method opens new perspectives in the development of specific computer-aided design tools for additive manufacturing, based on mesh modeling and surface subdivision. These approaches and slicing tools are suitable for parallel computation, therefore allowing the implementation of algorithms dedicated to graphics cards.

Bayesian Optimization of Energy-Absorbing Lattice Structures for Additive Manufacturing

2020 ◽  
Author(s):  
Nathan Hertlein ◽  
Kumar Vemaganti ◽  
Sam Anand
Keyword(s):  
Finite Element ◽  
Additive Manufacturing ◽  
Optimization Problems ◽  
Lattice Structure ◽  
Structure Design ◽  
Bayesian Optimization ◽  
Fe Model ◽  
Lattice Structures ◽  
Element Analysis ◽  
Overhang Angle

Abstract Additive manufacturing has enabled the production of intricate lattice structures that meet stringent design requirements with minimal mass. While many methods such as lattice-based topology optimization are being developed to design lightweight structures for static loading, there is a need for design tools for achieving dynamic loading requirements. Lattice structures have shown particular promise as low-mass energy absorbers, but the computational expense of nonlinear finite element analysis and the difficulty of obtaining objective gradient information has made their optimization for impact loading particularly challenging. This study proposes a Bayesian optimization framework to determine the lattice structure design that provides the best performance under a specified impact, while managing the structure’s mass. Considering nonlinear effects such as plasticity and strain rate sensitivity, a 2D explicit finite element (FE) model is constructed for two lattice unit cell types under impact, and parameterized with respect to geometric attributes such as height, width, and strut thickness. These parameters are considered design variables in a minimization problem with an objective function that balances part volume with a common injury metric, the head injury criterion (HIC). Penalty values are assigned to designs that fail to absorb the entire impact. Design for additive manufacturing (DFAM) constraints including minimum feature thickness and maximum overhang angle are applied to ensure that the optimal design can be manufactured without subsequent manual refinement or post-processing. The best optimizer hyperparameters are then carried over into larger optimization problems involving lattice structures. Future work could include expanding this framework to allow for lattice structure designs with arbitrary boundaries.

Computer-Aided Gear Product Realization

2018 ◽  
Author(s):  
Alireza Yazdanshenas ◽  
Emilli Morrison ◽  
Chung-Hyun Goh ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Computer Aided Design ◽  
Interaction Analysis ◽  
Gear Tooth ◽  
Integrated Design ◽  
System Level ◽  
Trial And Error ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Gear Design ◽  
Computer Aided

To save time and resources, many are making the transition to developing their ideas virtually. Computer-aided gear production realization is becoming more and more desired in the industry. To produce gears with custom qualities, such as material, weight and shape, the trial and error approach has yielded the best results. However, trial and error is costly and time consuming. The computer-aided integrated design and manufacturing approach is intended to resolve these drawbacks. A simple one stage reduction spur gearbox is used as an example in a case study. First, the gear geometry is developed using computer aided design (CAD) modeling. Next, using MATLAB/Simulink, the gear assembly is connected virtually to other subsystems for system expectations and interaction analysis. Finally, using finite element analysis (FEA) tools such as ABAQUS, a dynamic FEA of the gear integration is completed to analyze the stress concentrations and gear tooth failures. Through this method of virtual gear design, customized dimensions and specifications of gears for satisfying system-level requirements can be developed, thereby saving time and manufacturing costs for any custom gear design request.

LATTICE STRUCTURE OPTIMIZATION WITH ORIENTATION-DEPENDENT MATERIAL PROPERTIES

2021 ◽  
pp. 1-33
Author(s):  
Conner Sharpe ◽  
Carolyn Seepersad
Keyword(s):  
Additive Manufacturing ◽  
Design Process ◽  
Material Properties ◽  
Computational Models ◽  
Lattice Structure ◽  
Lattice Structures ◽  
Performance Improvements ◽  
Structural Applications ◽  
Manufacturing Techniques ◽  
And Performance

Abstract Advances in additive manufacturing techniques have enabled the production of parts with complex internal geometries. However, the layer-based nature of additive processes often results in mechanical properties that vary based on the orientation of the feature relative to the build plane. Lattice structures have been a popular design application for additive manufacturing due to their potential uses in lightweight structural applications. Many recent works have explored the modeling, design, and fabrication challenges that arise in the multiscale setting of lattice structures. However, there remains a significant challenge in bridging the simplified computational models used in the design process and the more complex properties actually realized in fabrication. This work develops a design approach that captures orientation-dependent material properties that have been observed in metal AM processes while remaining suitable for use in an iterative design process. Exemplar problems are utilized to investigate the potential design changes and performance improvements that can be attained by taking the directional dependence of the manufacturing process into account in the design of lattice structures.

Internet-Based Delivery of CAD/CAM Capability: An Industry Case Study

1998 ◽  
Author(s):  
Simon Szykman ◽  
Ram D. Sriram
Keyword(s):  
Small Businesses ◽  
Computer Aided Design ◽  
Data Exchange ◽  
Engineering Industry ◽  
Product Development Process ◽  
The Internet ◽  
Design Data ◽  
Computer Aided ◽  
Cad Cam

Abstract This paper presents a case study in the use of the Internet as a medium for exchange of information and delivery of computer-aided design and computer-aided manufacturing (CAD/CAM) capability. The case study describes a collaboration among researchers and staff at the National Institute of Standards and Technology (NIST), and Thar Designs, Inc., a small business in Pittsburgh, PA that designs and sells high-pressure fluid pumps. The objective of this case study is to identify the needs of small businesses in engineering industry in the area of Internet-based CAD/CAM services. The Internet-based interaction performed in this study encompassed various stages in an iterative product development process, consisting of design, data exchange, manufacturability analysis, and fabrication of a prototype.

Software Development Tools to Automate CAD/CAM Systems

2014 ◽  
pp. 190-224 ◽  
Author(s):  
N. A. Fountas ◽  
A. A. Krimpenis ◽  
N. M. Vaxevanidis
Keyword(s):  
Process Planning ◽  
Computer Aided Design ◽  
Data Exchange ◽  
Computational Thinking ◽  
Product Lifecycle Management ◽  
Engineering Software ◽  
Computer Aided ◽  
Cad Cam ◽  
Manufacturing Software ◽  
Software Automation

In today’s modern manufacturing, software automation is crucial element for leveraging novel methodologies and integrate various engineering software environments such Computer aided design (CAD), Computer aided process planning (CAPP), or Computer aided manufacturing (CAM) with programming modules with a common and a comprehensive interface; thus creating solutions to cope with repetitive tasks or allow argument passing for data exchange. This chapter discusses several approaches concerning engineering software automation and customization by employing programming methods. The main focus is given to design, process planning and manufacturing since these phases are of paramount importance when it comes to product lifecycle management. For this reason, case studies concerning software automation and problem definition for the aforementioned platforms are presented mentioning the benefits of programming when guided by successful computational thinking and problem mapping.

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.

Geometric Modelling and Computer-Aided Design

2009 ◽  
pp. 1-31
Author(s):  
Xun Xu
Keyword(s):  
Computer Aided Design ◽  
Data Exchange ◽  
Geometric Model ◽  
Point Of View ◽  
Geometric Modelling ◽  
Cad Systems ◽  
Cad System ◽  
Wire Frame ◽  
Computer Aided ◽  
Aided Design

One of the key activities in any product design process is to develop a geometric model of the product from the conceptual ideas, which can then be augmented with further engineering information pertaining to the application area. For example, the geometric model of a design may be developed to include material and manufacturing information that can later be used in computer-aided process planning and manufacturing (CAPP/CAM) activities. A geometric model is also a must for any engineering analysis, such as finite elopement analysis (FEA). In mathematic terms, geometric modelling is concerned with defining geometric objects using computational geometry, which is often, represented through computer software or rather a geometric modelling kernel. Geometry may be defined with the help of a wire-frame model, surface model, or solid model. Geometric modelling has now become an integral part of any computer-aided design (CAD) system. In this chapter, various geometric modelling approaches, such as wire-frame, surface, and solid modelling will be discussed. Basic computational geometric methods for defining simple entities such as curves, surfaces, and solids are given. Concepts of parametric, variational, history-based, and history-free CAD systems are explained. These topics are discussed in this opening chapter because (a) CAD was the very first computer-aided technologies developed and (b) its related techniques and methods have been pervasive in the other related subjects like computer-aided manufacturing. This chapter only discusses CAD systems from the application point of view; CAD data formats and data exchange issues are covered in the second chapter.

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