Study on Machining Deformation Errors in Spiral Finish Milling of Thin-Walled Blades

2011 ◽  
Vol 314-316 ◽  
pp. 1773-1777
Author(s):  
Wei Wei Liu ◽  
Pei Chen ◽  
Xiao Juan Gao ◽  
Chen Wei Shan ◽  
Min Wan
Keyword(s):  
Geometric Dimension ◽  
Beam Theory ◽  
Milling Process ◽  
Simplified Model ◽  
Machining Deformation ◽  
Proposed Model ◽  
Thin Walled ◽  
The Relationship ◽  
Torsion Deformation

In this paper, a new procedure is proposed to study the deformation errors for spiral milling process of blade, which can be simplified as a stepwise beam based on the geometry and clamping characteristics. Kirchhoff beam theory is adopted to analyze the bending and torsion deformation. The relationship between machining deformation errors and the workpiece’s geometric dimension are also established based on the simplified model. Corresponding algorithms are realized by MATLAB codes. Experiment test shows that the results predicted by the proposed model are in well agreement with measured ones.

scholarly journals Numerical Analysis for U-Shaped Thin-Walled Structure Reinforced Timber Beam Based on Thin-Layer Beam Theory

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Hui Liu ◽  
Jun Hu ◽  
Guohui Li ◽  
Guangying Mo
Keyword(s):  
Thin Layer ◽  
Beam Theory ◽  
Accurate Solution ◽  
Alloy Sheet ◽  
Element Analysis ◽  
Rational Engineering ◽  
Proposed Model ◽  
Wide Range ◽  
Thin Walled ◽  
Beam Height

This paper presents a theoretical model, taking into account the shear deformation subjected to the influence of U-shaped member by geometric parameters as flange height based on thin-layer beam theory, to analyze the structural bending behavior of U-shaped member reinforced timber composite beams, and the feasible design forms of U-section have been pointed out. The algorithm for this composite beam is the most practical and effective method to meet the accurate solution. The formulas for the common forms of U-section are presented. It aims to develop a rational engineering approach. The proposed model has been validated by comparing the results obtained in the present analysis with experimental results and finite element analysis. Furthermore, the results suggested that the value of flange height can be one-fifth the beam height based on the present analysis by comparison of two types of beams. And it is shown that the model provided here correlates consistently and satisfactorily with a wide range of timber beams reinforced by a thin-walled structure such as steel or aluminum alloy sheet bonded to their tension faces.

FEM Simulations on the Milling Dynamics of the Thin-Walled Structure Components

2006 ◽  
Vol 315-316 ◽  
pp. 736-741 ◽  
Author(s):  
K. Wu ◽  
Ning He
Keyword(s):  
Cutting Parameters ◽  
Simplified Model ◽  
Fem Simulations ◽  
Machining Conditions ◽  
Proposed Model ◽  
Thin Walled ◽  
Simulation Results ◽  
Milling Dynamics

The existent studies on milling dynamics of the thin-walled structure components are reviewed first, then a kind of FEM simplified model analyzing the milling dynamics of the thin-walled structure components is proposed. Based on the proposed model, some simulations have been done under different cutting parameters and different machining conditions. At last, the simulation results are analyzed and discussed.

Numerical Simulation Investigation on Machining Deformation of Aviation Thin-Walled Parts Caused by Residual Stress

2021 ◽  
Vol 1032 ◽  
pp. 186-191
Author(s):  
Jie Deng ◽  
Shi Jie Zhou ◽  
Han Jun Gao ◽  
Ming Hui Lin ◽  
Xin Li
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Residual Stresses ◽  
Simulation Models ◽  
Cutting Parameters ◽  
Stress Distributions ◽  
Machining Deformation ◽  
Proposed Model ◽  
Thin Walled ◽  
Structural Parts

Holistic thin-walled parts are common structural parts of modern aircraft to reduce the weight and increase the stiffness. Over 90% of the materials are removed from the blank, as a result, large machining deformations occur to the parts, which causes the manufacturing discrepancies and even the scrap parts. In this paper, numerical simulation models are established to predict the machining deformation of two typical aviation thin-walled parts. The blank initial and machining induced residual stresses, as well as the cutting parameters, are considered in the model. The deformations and stresses after machining are calculated using the proposed model, and the deformation and stress distributions are analyzed.

The Influence of Cognitive and Affective Reactions to Feedback on Subsequent Goals

2010 ◽  
Vol 15 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Remus Ilies ◽  
Timothy A. Judge ◽  
David T. Wagner
Keyword(s):  
Performance Feedback ◽  
Business School ◽  
Structural Equation ◽  
Emotional Reactions ◽  
Equation Model ◽  
Proposed Model ◽  
And Performance ◽  
Dispositional Measure ◽  
The Relationship ◽  
Reactions To Feedback

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.

Post-buckling inelastic analysis of thin-walled metal members using the Generalised Beam Theory

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Dinar Camotim ◽  
Miguel Abambres
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Beam Theory ◽  
Flow Theory ◽  
Promising Alternative ◽  
Inelastic Analysis ◽  
Post Buckling ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalised Beam Theory

A 2nd order inelastic Generalised Beam Theory (GBT) formulation based on the J2 flow theory is proposed, being a promising alternative to the shell finite element method. Its application is illustrated for an I-section beam and a lipped-C column. GBT results were validated against ABAQUS, namely concerning equilibrium paths, deformed configurations, and displacement profiles. It was concluded that the GBT modal nature allows (i) precise results with only 22% of the number of dof required in ABAQUS, as well as (ii) the understanding (by means of modal participation diagrams) of the behavioral mechanics in any elastoplastic stage of member deformation .

First and Second Order Elastoplastic Analyses of Thin-Walled Metal Members using Generalized Beam Theory

2018 ◽  
Author(s):  
Miguel Abambres
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Cross Section ◽  
Beam Theory ◽  
Second Order ◽  
Flow Rule ◽  
Non Linear ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalized Beam Theory

Original Generalized Beam Theory (GBT) formulations for elastoplastic first and second order (postbuckling) analyses of thin-walled members are proposed, based on the J2 theory with associated flow rule, and valid for (i) arbitrary residual stress and geometric imperfection distributions, (ii) non-linear isotropic materials (e.g., carbon/stainless steel), and (iii) arbitrary deformation patterns (e.g., global, local, distortional, shear). The cross-section analysis is based on the formulation by Silva (2013), but adopts five types of nodal degrees of freedom (d.o.f.) – one of them (warping rotation) is an innovation of present work and allows the use of cubic polynomials (instead of linear functions) to approximate the warping profiles in each sub-plate. The formulations are validated by presenting various illustrative examples involving beams and columns characterized by several cross-section types (open, closed, (un) branched), materials (bi-linear or non-linear – e.g., stainless steel) and boundary conditions. The GBT results (equilibrium paths, stress/displacement distributions and collapse mechanisms) are validated by comparison with those obtained from shell finite element analyses. It is observed that the results are globally very similar with only 9% and 21% (1st and 2nd order) of the d.o.f. numbers required by the shell finite element models. Moreover, the GBT unique modal nature is highlighted by means of modal participation diagrams and amplitude functions, as well as analyses based on different deformation mode sets, providing an in-depth insight on the member behavioural mechanics in both elastic and inelastic regimes.

scholarly journals Context-Aware Neural Machine Translation for Korean Honorific Expressions

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1589
Author(s):  
Yongkeun Hwang ◽  
Yanghoon Kim ◽  
Kyomin Jung
Keyword(s):  
Machine Translation ◽  
Deep Neural Networks ◽  
Contextual Information ◽  
Context Aware ◽  
Neural Machine Translation ◽  
Translation Quality ◽  
Sentence Level ◽  
Proposed Model ◽  
The Given ◽  
The Relationship

Neural machine translation (NMT) is one of the text generation tasks which has achieved significant improvement with the rise of deep neural networks. However, language-specific problems such as handling the translation of honorifics received little attention. In this paper, we propose a context-aware NMT to promote translation improvements of Korean honorifics. By exploiting the information such as the relationship between speakers from the surrounding sentences, our proposed model effectively manages the use of honorific expressions. Specifically, we utilize a novel encoder architecture that can represent the contextual information of the given input sentences. Furthermore, a context-aware post-editing (CAPE) technique is adopted to refine a set of inconsistent sentence-level honorific translations. To demonstrate the efficacy of the proposed method, honorific-labeled test data is required. Thus, we also design a heuristic that labels Korean sentences to distinguish between honorific and non-honorific styles. Experimental results show that our proposed method outperforms sentence-level NMT baselines both in overall translation quality and honorific translations.

scholarly journals An Attention-Based Model Using Character Composition of Entities in Chinese Relation Extraction

Information ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 79 ◽  
Author(s):  
Xiaoyu Han ◽  
Yue Zhang ◽  
Wenkai Zhang ◽  
Tinglei Huang
Keyword(s):  
Language Processing ◽  
Large Scale ◽  
Named Entity Recognition ◽  
Relation Extraction ◽  
Entity Recognition ◽  
Additional Information ◽  
Named Entity ◽  
Proposed Model ◽  
The Relationship ◽  
Crucial Part

Relation extraction is a vital task in natural language processing. It aims to identify the relationship between two specified entities in a sentence. Besides information contained in the sentence, additional information about the entities is verified to be helpful in relation extraction. Additional information such as entity type getting by NER (Named Entity Recognition) and description provided by knowledge base both have their limitations. Nevertheless, there exists another way to provide additional information which can overcome these limitations in Chinese relation extraction. As Chinese characters usually have explicit meanings and can carry more information than English letters. We suggest that characters that constitute the entities can provide additional information which is helpful for the relation extraction task, especially in large scale datasets. This assumption has never been verified before. The main obstacle is the lack of large-scale Chinese relation datasets. In this paper, first, we generate a large scale Chinese relation extraction dataset based on a Chinese encyclopedia. Second, we propose an attention-based model using the characters that compose the entities. The result on the generated dataset shows that these characters can provide useful information for the Chinese relation extraction task. By using this information, the attention mechanism we used can recognize the crucial part of the sentence that can express the relation. The proposed model outperforms other baseline models on our Chinese relation extraction dataset.

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