scholarly journals Development of a Novel System for Adaptive Machining of Near-Net-Shape Components

2021 ◽  
Author(s):  
Zhengcai Zhao ◽  
Shengtao Lin ◽  
Yucan Fu
Keyword(s):  
Shape Reconstruction ◽  
Free Form ◽  
Nc Programming ◽  
Spatial Deformation ◽  
Manufacturing Efficiency ◽  
Adaptive Machining ◽  
Machining Allowance ◽  
Near Net Shape ◽  
Cutter Position

Near-net-shape components are popular among the aerospace industry for low material waste and high manufacturing efficiency. However, it is difficult to machine such components into final shapes because the machining allowance is often distributed unevenly and even insufficient. This paper proposed a novel system for adaptive machining near-net-shape components, which integrates units like on-machine measurement based on probe and ultrasonic-sensor, machining allowance constrained localization, tolerance range constrained shape reconstruction, and TCP (tool cutter position) template-based NC programming. Firstly, localization and free form deformation (FFD)-based shape construction are performed within the tolerance ranges of the component, and an even distribution of the machining allowance can be obtained. Next, the quick NC programming that directly manipulates the TCPs by using spatial deformation is introduced. Last, the data transmission between units is illustrated. A case study of the machining titanium turbine blade is performed, which validates the proposed system.

A case study evaluation of a community multidisciplinary team in South East England using a mixed-method approach

2020 ◽  
Vol 70 (suppl 1) ◽  
pp. bjgp20X711569
Author(s):  
Jessica Wyatt Muscat
Keyword(s):  
Mental Health ◽  
Mixed Method ◽  
Social Care ◽  
Free Form ◽  
Normalisation Process Theory ◽  
Multidisciplinary Teams ◽  
Mixed Method Approach ◽  
Health And Social Care ◽  
Method Approach

BackgroundCommunity multidisciplinary teams (MDTs) represent a model of integrated care comprising health, social care, and the voluntary sector where members work collaboratively to coordinate care for those patients most at risk.AimThe evaluation will answer the question, ‘What are the enablers and what are the restrictors to the embedding of the case study MDT into the routine practice of the health and social care teams involved in the project?’MethodThe MDT was evaluated using a mixed-method approach with normalisation process theory as a methodological tool. Both quantitative and qualitative data were gathered through a questionnaire consisting of the NoMAD survey followed by free-form questions.ResultsThe concepts of the MDT were generally clear, and participants could see the potential benefits of the programme, though this was found to be lower in GPs. Certain professionals, particularly mental health and nursing professionals, found it difficult to integrate the MDT into normal working patterns because of a lack of resources. Participants also felt there was a lack of training for MDT working. A lack of awareness of evidence supporting the programme was shown particularly within management, GP, and nursing roles.ConclusionSpecific recommendations have been made in order to improve the MDT under evaluation. These include adjustments to IT systems and meeting documentation, continued education as to the purpose of the MDT, and the engagement of GPs to enable better buy-in. Recommendations were made to focus the agenda with specialist attendance when necessary, and to expand the MDT remit, particularly in mental health and geriatrics.

scholarly journals Surface Integrity Investigation to Determine Rough Milling Effects for Assessment of Machining Allowance for Subsequent Finish Milling of Alloy 718

2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Jonas Holmberg ◽  
Anders Wretland ◽  
Johan Berglund ◽  
Tomas Beno ◽  
Anton Milesic Karlsson
Keyword(s):  
Surface Integrity ◽  
Milling Process ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Milling Operations ◽  
Milling Operation ◽  
Machining Allowance ◽  
Rough Milling

The planned material volume to be removed from a blank to create the final shape of a part is commonly referred to as allowance. Determination of machining allowance is essential and has a great impact on productivity. The objective of the present work is to use a case study to investigate how a prior rough milling operation affects the finish machined surface and, after that, to use this knowledge to design a methodology for how to assess the machining allowance for subsequent milling operations based on residual stresses. Subsequent milling operations were performed to study the final surface integrity across a milled slot. This was done by rough ceramic milling followed by finish milling in seven subsequent steps. The results show that the up-, centre and down-milling induce different stresses and impact depths. Employing the developed methodology, the depth where the directional influence of the milling process diminishes has been shown to be a suitable minimum limit for the allowance. At this depth, the plastic flow causing severe deformation is not present anymore. It was shown that the centre of the milled slot has the deepest impact depth of 500 µm, up-milling caused an intermediate impact depth of 400 µm followed by down milling with an impact depth of 300 µm. With merged envelope profiles, it was shown that the effects from rough ceramic milling are gone after 3 finish milling passes, with a total depth of cut of 150 µm.

Knowledge Recommendation System for Human-Robot Collaborative Disassembly Using Knowledge Graph

2021 ◽  
Author(s):  
Yang Hu ◽  
Yiwen Ding ◽  
Feng Xu ◽  
Jiayi Liu ◽  
Wenjun Xu ◽  
...  
Keyword(s):  
Recommendation System ◽  
Industrial Robots ◽  
Knowledge Graph ◽  
Disassembly Process ◽  
Knowledge Based ◽  
Manufacturing Efficiency ◽  
Human Operators ◽  
Traditional Manufacturing ◽  
Human Robot Collaboration

Abstract In recent years, more and more attention has been paid to Human-Robot Collaborative Disassembly (HRCD) in the field of industrial remanufacturing. Compared with the traditional manufacturing, HRCD helps to improve the manufacturing flexibility with considering the manufacturing efficiency. In HRCD, knowledge could be obtained from the disassembly process and then provides useful information for the operator and robots to execute their disassembly tasks. Afterwards, a crucial point is to establish a knowledge-based system to facilitate the interaction between human operators and industrial robots. In this context, a knowledge recommendation system based on knowledge graph is proposed to effectively support Human-Robot Collaboration (HRC) in disassembly. A disassembly knowledge graph is constructed to organize and manage the knowledge in the process of HRCD. After that, based on this, a knowledge recommendation procedure is proposed to recommend disassembly knowledge for the operator. Finally, the case study demonstrates that the developed system can effectively acquire, manage and visualize the related knowledge of HRCD, and then assist the human operator to complete the disassembly task by knowledge recommendation, thus improving the efficiency of collaborative disassembly. This system could be used in the human-robot collaboration disassembly process for the operators to provide convenient knowledge recommendation service.

Mechanical Design for Accuracy of Linkage Servo Press for Near-Net Shape Forming

2018 ◽  
Author(s):  
Jing Tao ◽  
Huanan Qian ◽  
Suiran Yu
Keyword(s):  
Mechanical Design ◽  
Structure Design ◽  
Tolerance Allocation ◽  
Component Level ◽  
Eccentric Load ◽  
Servo Press ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Heavy Loads

The accuracy of machine is important to achieving highly accurate shapes. This paper is focused on mechanical design of highly accurate mechanical linkage servo press applicable to (near-)net shape forming. The effects of geometric errors, deformations under heavy loads and ram tilting are analyzed. A top-down design for accuracy approach is proposed: First, accuracy model for identification of inaccuracy-causing factors and their interlinking relations is developed. Then, based on this model, top accuracy index are decomposed and translated into structure design specifications at component level. Both analytic and simulation methods are employed for design for accuracy in aspects of dimensional and geometric tolerance allocation, stiffness synthesis and anti-eccentric load capability. A case study of mechanical design for accuracy of a six-linkage mechanical servo press is also presented to demonstrate and test the proposed design approaches.

Parting Line Formation by Slicing a Trimmed Surface Model

1996 ◽  
Author(s):  
T. Wong ◽  
S. T. Tan ◽  
W. S. Sze
Keyword(s):  
Product Design ◽  
Free Form ◽  
Surface Model ◽  
Curved Surfaces ◽  
Line Formation ◽  
Planar Surfaces ◽  
Manufacturing Efficiency ◽  
Computer Aided ◽  
Trimmed Surface ◽  
Free Form Surfaces

Abstract The parting line on a product affects the final layout of the mould blocks and hence the manufacturing efficiency. The increased usage of free-form surfaces in product design increases the burden of computer aided parting line and parting surface determination. Previous proposed algorithms may not be sufficient to deal with such situation since most of them were originally designed to deal with products having planar surfaces or simple curved surfaces. A new algorithm is proposed to deal with such situation. The algorithm adopted a recursive uneven slicing on a trimmed surface model. The method provides a quick and efficient way of locating the parting line of a product.

The Applied Research on Improved Design of Product Forms Based on Reverse Engineering Technology

2013 ◽  
Vol 422 ◽  
pp. 89-93
Author(s):  
Xiao Ping Hu ◽  
Yun Feng Lin
Keyword(s):  
Point Cloud ◽  
Shape Reconstruction ◽  
Product Form ◽  
Free Form ◽  
Point Cloud Data ◽  
Nurbs Surface ◽  
Engineering Technology ◽  
Cloud Data ◽  
Improved Design ◽  
Product Forms

The improved design of the form of product is related to the free-form surface treatment, but the use of the product which forms the point cloud data to obtain a satisfactory surface reconstruction is difficult. NURBS surface fitting technique, the appearance of the product first be classified according to form, and then accordingly the product shape reconstruction, it is much easier. Facts have proved that the conditions does not require high precision, the use of NURBS fitting to reconstruct the free surface able to obtain a satisfactory product form. This improved design of the product form is practical.

scholarly journals An approach for machining allowance optimization of complex parts with integrated structure

2015 ◽  
Vol 2 (4) ◽  
pp. 248-252 ◽  
Author(s):  
Ying Zhang ◽  
Dinghua Zhang ◽  
Baohai Wu
Keyword(s):  
Nc Machining ◽  
Machining Process ◽  
Solution Strategy ◽  
Adaptive Machining ◽  
Machining Allowance ◽  
Linear Friction ◽  
Alignment Process ◽  
Workpiece Localization ◽  
Complex Parts ◽  
Symmetric Block

Abstract Currently composite manufacturing process, such as linear friction welding plus NC machining, is the main method for the manufacturing and repairing of complex parts with integrated structure. Due to different datum position and inevitable distortion from different processes, it is important to ensure sufficient machining allowance for complex parts during the NC machining process. In this paper, a workpiece localization approach for machining allowance optimization of complex parts based on CMM inspection is developed. This technique concerns an alignment process to ensure sufficient stock allowance for the single parts as well as the whole integrated parts. The mathematical model of the constrained alignment is firstly established, and then the symmetric block solution strategy is proposed to solve the optimization model. Experiment result shows that the approach is appropriate and feasible to distribute the machining allowance for the single and whole parts for adaptive machining of complex parts. Highlights An approach for machining allowance optimization of complex parts based on CMM inspection is developed. An alignment process to ensure sufficient stock allowance for the whole integrated parts is concerned. The symmetric block solution strategy is proposed to solve the constrained alignment model.

scholarly journals Development of multiaxial warp knitting technology for production of three-dimensional near net shape shell preforms

2016 ◽  
Vol 87 (10) ◽  
pp. 1226-1241
Author(s):  
Vignaesh Sankaran ◽  
Steffen Rittner ◽  
Lars Hahn ◽  
Chokri Cherif
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Single Step ◽  
Free Form ◽  
Warp Yarn ◽  
Component Structure ◽  
Composite Production ◽  
Near Net Shape ◽  
Material Utilization ◽  
Form Stability

The possibility of direct preforming in the near net shape of final component structure with load- and shape-conforming fiber orientations is highly essential in composite production, not only to reduce costs but also to attain better mechanical properties and form stability. Based on the concept of varying the reinforcement yarn lengths during the feed-in (warp yarn delivery) and segmented doffing, synchronous working numerically controlled warp yarn delivery and doffing machine modules have been newly developed for multiaxial warp knitting machines to create a resource efficient textile process chain by a single-step, large-scale oriented production of load- and form-conforming warp knitted three-dimensional shell preforms with free-form geometrical surfaces. Such customized preforms in the near component net shape offer higher material utilization and increased lightweight potential.

A New Ergonomics Manikin Generation Method from Real 3D Scanning Body

2010 ◽  
Vol 26-28 ◽  
pp. 1075-1078 ◽  
Author(s):  
Zhan Xun Dong ◽  
Zhen Yu Gu ◽  
Zhan Wei Wu
Keyword(s):  
3D Scanning ◽  
Parametric Modeling ◽  
Human Model ◽  
Free Form ◽  
Model Optimization ◽  
Body Scanning ◽  
Modeling Methods ◽  
Fundamental Information ◽  
Model Phase

Computer-Aided Ergonomics (CAE) makes it possible that people may build a virtual environment for ergonomics evaluation in the product’s digital model phase. Manikin with anthropometry data supplies fundamental information in design lifecycle, so it also plays an important role in CAE software. Thanks to the 3D scanning technology, we developed a new ergonomics manikin generation method which could create free-form surface human model from real body. Generation method concluded body scanning, model optimization, and combining skeleton stages. Finally, case study proved that Paper’s method could generate more exact manikin than former parametric modeling methods, and it would benefit customized products design.

Sign in / Sign up

Export Citation Format

Share Document