scholarly journals Direct Digital Subtractive Manufacturing of a Functional Assembly Using Voxel-Based Models

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Roby Lynn ◽  
Mahmoud Dinar ◽  
Nuodi Huang ◽  
James Collins ◽  
Jing Yu ◽  
...  
Keyword(s):  
Process Planning ◽  
Computer Aided Design ◽  
Complex Geometry ◽  
Geometric Constraints ◽  
Machining Process ◽  
Layer By Layer ◽  
User Input ◽  
Computer Aided ◽  
Subtractive Manufacturing ◽  
The Creation

Direct digital manufacturing (DDM) is the creation of a physical part directly from a computer-aided design (CAD) model with minimal process planning and is typically applied to additive manufacturing (AM) processes to fabricate complex geometry. AM is preferred for DDM because of its minimal user input requirements; as a result, users can focus on exploiting other advantages of AM, such as the creation of intricate mechanisms that require no assembly after fabrication. Such assembly free mechanisms can be created using DDM during a single build process. In contrast, subtractive manufacturing (SM) enables the creation of higher strength parts that do not suffer from the material anisotropy inherent in AM. However, process planning for SM is more difficult than it is for AM due to geometric constraints imposed by the machining process; thus, the application of SM to the fabrication of assembly free mechanisms is challenging. This research describes a voxel-based computer-aided manufacturing (CAM) system that enables direct digital subtractive manufacturing (DDSM) of an assembly free mechanism. Process planning for SM involves voxel-by-voxel removal of material in the same way that an AM process consists of layer-by-layer addition of material. The voxelized CAM system minimizes user input by automatically generating toolpaths based on an analysis of accessible material to remove for a certain clearance in the mechanism's assembled state. The DDSM process is validated and compared to AM using case studies of the manufacture of two assembly free ball-in-socket mechanisms.

scholarly journals The Influence of Exposure Energy Density on Porosity and Microhardness of the SLM Additive Manufactured Elements

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2304 ◽  
Author(s):  
Janusz Kluczyński ◽  
Lucjan Śnieżek ◽  
Krzysztof Grzelak ◽  
Janusz Mierzyński
Keyword(s):  
Computer Aided Design ◽  
Complex Geometry ◽  
Final Analysis ◽  
Machine Building ◽  
Layer By Layer ◽  
Laser Melting ◽  
Measurement Results ◽  
Computer Aided ◽  
Exposure Energy ◽  
Aided Design

Selective laser melting (SLM) is an additive manufacturing technique. It allows elements with very complex geometry to be produced using metallic powders. A geometry of manufacturing elements is based only on 3D computer-aided design (CAD) data. The metal powder is melted selectively layer by layer using an ytterbium laser. This paper contains the results of porosity and microhardness analysis made on specimens manufactured during a specially prepared process. Final analysis helped to discover connections between changing hatching distance, exposure speed and porosity. There were no significant differences in microhardness and porosity measurement results in the planes perpendicular and parallel to the machine building platform surface.

Constraints and limitations of concrete 3D printing in architecture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chien-Ho Ko
Keyword(s):  
3D Printing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Research Approach ◽  
Layer By Layer ◽  
Content Type ◽  
Improve Design ◽  
Study Results ◽  
Computer Aided ◽  
Property Control

Purpose Additive manufacturing of concrete (AMoC) is an emerging technology for constructing buildings. However, due to the nature of the concrete property and constructing buildings in layers, constraints and limitations are encountered while applying AMoC in architecture. This paper aims to analyze the constraints and limitations that may be encountered while using AMoC in architecture. Design/methodology/approach A descriptive research approach is used to conduct this study. First, basic notions of AMoC are introduced. Then, challenges of AMoC, including hardware, material property, control and design, are addressed. Finally, strategies that may be used to overcome the challenges are discussed. Findings Factors influencing the success of AMoC include hardware, material, control methods, manufacturing process and design. Considering these issues in the early design phase is crucial to achieving a successful computer-aided design (CAD)/computer-aided manufacturing (CAM) integration to bring CAD and CAM benefits into the architecture industry. Originality/value In three-dimensional (3D) printing, objects are constructed layer by layer. Printing results are thus affected by the additive method (such as toolpath) and material properties (such as tensile strength and slump). Although previous studies attempt to improve AMoC, most of them focus on the manufacturing process. However, a successful application of AMoC in architecture needs to consider the possible constraints and limitations of concrete 3D printing. So far, research on the potential challenges of applying AMoC in architecture from a building lifecycle perspective is still limited. The study results of this study could be used to improve design and construction while applying AMoC in architecture.

An oriented feature extraction and recognition approach for concave-convex mixed interacting features in cast-then-machined parts

2018 ◽  
Vol 233 (4) ◽  
pp. 1269-1288 ◽  
Author(s):  
Haichao Wang ◽  
Jie Zhang ◽  
Xiaolong Zhang ◽  
Changwei Ren ◽  
Xiaoxi Wang ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Computer Aided Design ◽  
Feature Recognition ◽  
Freeform Surface ◽  
Layer By Layer ◽  
Computer Aided Process Planning ◽  
Computer Aided ◽  
Machined Parts ◽  
Aided Design ◽  
Interacting Features

Feature recognition is an important technology of computer-aided design/computer-aided engineering/computer-aided process planning/computer-aided manufacturing integration in cast-then-machined part manufacturing. Graph-based approach is one of the most popular feature recognition methods; however, it cannot still solve concave-convex mixed interacting feature recognition problem, which is a common problem in feature recognition of cast-then-machined parts. In this study, an oriented feature extraction and recognition approach is proposed for concave-convex mixed interacting features. The method first extracts predefined features directionally according to the rules generated from attributed adjacency graphs–based feature library and peels off them from part model layer by layer. Sub-features in an interacting feature are associated via hints and organized as a feature tree. The time cost is reduced to less than [Formula: see text] by eliminating subgraph isomorphism and matching operations. Oriented feature extraction and recognition approach recognizes non-freeform-surface features directionally regardless of the part structure. Hence, its application scope can be extended to multiple kinds of non-freeform-surface parts by customizing. Based on our findings, implementations on prismatic, plate, fork, axlebox, linkage, and cast-then-machined parts prove that the proposed approach is applicable on non-freeform-surface parts and effectively recognize concave-convex mixed interacting feature in various mechanical parts.

scholarly journals Engineering working operations based on parameters of product manufacturability using a computer-aided design algorithm

2022 ◽  
Vol 25 (6) ◽  
pp. 708-719
Author(s):  
D. A. Ishenin ◽  
A. S. Govorkov
Keyword(s):  
Computer Aided Design ◽  
Production Costs ◽  
Machining Process ◽  
Processing Route ◽  
Mechanical Processing ◽  
Design Algorithm ◽  
Industrial Data ◽  
Production Processes ◽  
Computer Aided ◽  
Aided Design

The study aimed to develop an algorithm for computer-aided design (CAD) of working operations. A processing route for machining components was developed based on the criteria of production manufacturability, industrial data and a digital model of the product. The process of machining a workpiece was analysed using a method of theoretical separation. The machining process of a frame workpiece was used as a model. The identified formal parameters formed a basis for developing a CAD algorithm and a model of manufacturing route associated with the mechanical processing of a work-piece applying a condition-action rule, as well as mathematical logic. The research afforded a scheme for selecting process operations, given the manufacturability parameters of a product design. The concept of CAD algorithm was developed to design a production process of engineering products with given manufacturability parameters, including industrial data. The principle of forming a route and selecting a machining process was proposed. Several criteria of production manufacturability (labour intensity, consumption of materials, production costs) were selected to evaluate mechanical processing. A CAD algorithm for designing technological operations considering the parameters of manufacturability was developed. The algorithm was tested by manufacturing a frame workpiece. The developed algorithm can be used for reducing labour costs and development time, at the same time as improving the quality of production processes. The formalisation of process design is a crucial stage in digitalisation and automation of all production processes.

scholarly journals ADDITIVE MANUFACTURING - APPLICATION OPPORTUNITIES FOR THE AVIATION INDUSTRY

2015 ◽  
Vol 6 (2) ◽  
pp. 63-86
Author(s):  
Dipesh Dhital ◽  
Yvonne Ziegler
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Computer Aided Design ◽  
Free Form ◽  
Aviation Industry ◽  
Layer By Layer ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Subtractive Manufacturing ◽  
Aided Design

Additive Manufacturing also known as 3D Printing is a process whereby a real object of virtually any shape can be created layer by layer from a Computer Aided Design (CAD) model. As opposed to the conventional Subtractive Manufacturing that uses cutting, drilling, milling, welding etc., 3D printing is a free-form fabrication process and does not require any of these processes. The 3D printed parts are lighter, require short lead times, less material and reduce environmental footprint of the manufacturing process; and is thus beneficial to the aerospace industry that pursues improvement in aircraft efficiency, fuel saving and reduction in air pollution. Additionally, 3D printing technology allows for creating geometries that would be impossible to make using moulds and the Subtractive Manufacturing of drilling/milling. 3D printing technology also has the potential to re-localize manufacturing as it allows for the production of products at the particular location, as and when required; and eliminates the need for shipping and warehousing of final products.

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.

Recognition of Freeform Surface Machining Features

2010 ◽  
Vol 10 (4) ◽  
Author(s):  
Jun Wang ◽  
Zhigang Wang ◽  
Weidong Zhu ◽  
Yingfeng Ji
Keyword(s):  
Critical Points ◽  
Computer Aided Design ◽  
Tool Path ◽  
Machining Process ◽  
Freeform Surface ◽  
Critical Surface ◽  
Machining Features ◽  
Computer Aided ◽  
Freeform Surface Machining ◽  
Machining Process Planning

This paper describes a method of machining feature recognition from a freeform surface based on the relationship between unique machining patches and critical points on a component’s surface. The method uses Morse theory to extract critical surface points by defining a scalar function on the freeform surface. Features are defined by region growing between the critical points using a tool path generation algorithm. Several examples demonstrate the efficiency of this approach. The recognized machining features can be directly utilized in a variety of downstream computer aided design/computer aided manufacturing (CAM) applications, such as the automated machining process planning.

scholarly journals Tension testing of additively manufactured specimens of 17-4 PH processed by Bound Metal Deposition

2021 ◽  
Vol 1201 (1) ◽  
pp. 012037
Author(s):  
F Bjørheim ◽  
I M La Torraca Lopez
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Industrial Sector ◽  
Metal Deposition ◽  
Layer By Layer ◽  
High Momentum ◽  
Subtractive Manufacturing ◽  
Tension Testing ◽  
Thermal Histories ◽  
Aided Design

Abstract In contrast to the traditional ways of subtractive manufacturing, additive manufacturing (AM), also known as 3D printing, adapts computer-aided design to iteratively build the component or part layer by layer. The technology has recently gained a high momentum, both within academia, but also within the industrial sector. However, it is common that parts produced by AM will have more defects than parts produced by traditional methods. The objective of this paper is to investigate a new method of additive manufacturing, namely the bound metal deposition method (BMD). This method seemed promising from the perspective that the metal is not iteratively being melted, similar to such as welding. In fact, the part is first printed, then washed, for then to be sintered. Consequently, avoiding the complex thermal histories/cycles. It was found that the material will exhibit anisotropic behaviour, and have a mesh of crack like defects, related to the printing orientation.

Common Product/Process Models for Integrating Manufacturing Simulation, Process Planning and Computer Aided Design

1996 ◽  
Author(s):  
Robert V. E. Bryant ◽  
Thomas J. Laliberty
Keyword(s):  
Process Planning ◽  
Collaborative Design ◽  
Computer Aided Design ◽  
Automatic Generation ◽  
Process Models ◽  
Virtual Enterprises ◽  
Computer Aided Process Planning ◽  
Manufacturing Simulation ◽  
Computer Aided ◽  
Aided Design

Abstract Integrated Product Process Development tools which minimize downstream manufacturing risk at the earliest design stages and avoid costly Design-Build-Test cycles are essential to achieving product profitability and meeting market windows. This paper summarizes initial work performed towards the development of the Manufacturing Simulation Driver (MSD) system which will demonstrate the automatic generation and execution of distributed manufacturing simulations. These simulation models are produced by Computer Aided Process Planning (CAPP) software tools which reason about Computer Aided Design (CAD) product models and produce manufacturing “scripts” from a process and resource model of a manufacturing facility. This capability will enable emerging virtual enterprises conducting collaborative design and manufacturing to simulate and prove out the manufacturing cycle of a product prior to launching production ramp-up. 1

“Modessa”: A Computer Aided Conceptual Design System

1996 ◽  
Author(s):  
Twan Kersten
Keyword(s):  
Conceptual Design ◽  
Design Problem ◽  
Computer Aided Design ◽  
Design Method ◽  
General Purpose ◽  
Design System ◽  
Design Teams ◽  
Design Alternatives ◽  
Computer Aided ◽  
The Creation

Abstract This paper describes the computer aided design system Modessa. Modessa is developed to support multi-disciplinary design teams in the conceptual design phase. Modessa is based on the “morphological design method” which decomposes the design problem into a number of so called functions. Then several alternatives are identified for each of these functions. These alternatives are visualized using pictures and arranged by function in a matrix which results in a so called “morphological overview”. Finally the alternatives are evaluated based on the customer requirements. The best alternatives for each function are combined to form the optimum solution for the design problem. Modessa supports multi-disciplinary design teams during the conceptual design process by: - Suggesting known design alternatives for design functions, thus leaving more time for the creation of novel design alternatives. - Offering a “common language” to objectively evaluate the design alternatives. - Simplifying the creation and reuse of the conceptual design documentation. Modessa is general purpose in nature and can be used for a wide variety of design applications. The kernel of Modessa is a design knowledge database that increases continuously as design teams add new functions (problems) and appropriate alternatives (solutions). In this paper the use of Modessa is illustrated by an industrial design example.

Sign in / Sign up

Export Citation Format

Share Document