scholarly journals Manufacturing Process beyond Conventional Plasticity Theory: Case Study in Manufacturing Low Spring Index Coil

2020 ◽  
Vol 1 (2) ◽  
pp. 98-104
Author(s):  
Yunan Prawoto ◽  
Sonia Manville ◽  
T Sakai ◽  
M Tanaka ◽  
T Gnauple-Herold
Keyword(s):  
Residual Stress ◽  
Fracture Mechanics ◽  
Material Properties ◽  
Manufacturing Process ◽  
Annealing Process ◽  
Plasticity Theory ◽  
Coil Spring ◽  
Academic World

In the academic world, conventional plasticity theory limits the cold process due to energy inefficiency, material properties and residual stress that may inhibit the quality of a product, and therefore usually not recommended. However, industrial competition pushes that limits against the edge. Knowing the consequences in advance helps reducing the damage that may have been caused by such a violation. This paper shows an example in the form of a case study. A coil spring with a very low spring index that academically suggested to be made using hot process was attempted to be manufactured using cold coiling machine. The case study shows that although it is possible, extra careful and timely handling must be done to successfully manufacture it. A coil with excessive residual stress is shown in this paper. That residual stress alone was capable in damaging the coil during manufacturing. The defect takes place after coiling and before tempering process. A fracture mechanics was used to analyze the failure, which is the splitting due to excessive residual stress. The case study also shows that the problem can be solved by speedy and subsequent stress relieve annealing process.

STANDARDIZED WORK IN TPS PRODUCTION LINE

2015 ◽  
Vol 76 (6) ◽  
Author(s):  
Nurul Hayati Abdul Halim ◽  
Ahmed Jaffar ◽  
Noriah Yusof ◽  
Roseelena Jaafar ◽  
Ahmad Naufal Adnan ◽  
...  
Keyword(s):  
Continuous Improvement ◽  
Production System ◽  
Manufacturing Process ◽  
Production Line ◽  
Assembly Line ◽  
Process Stability ◽  
Automotive Assembly ◽  
Study Implementation

This paper presents a case study implementation of one of the Toyota Production System (TPS) tools, known as Standardized Work (SW), in an automotive assembly line in Malaysia. The main functions of SW are to design, develop, document and visualize a set of a manufacturing process with detail and proper study of it. SW is conducted to raise production consistency and quality of a produced product and the job performed. With the proper SW implementation, good results have been obtained from the increase in efficiency, productivity, quality and process stability of the operator’s performance. Thus, the findings are consistent with TPS philosophies which are waste elimination and continuous improvement in any manufacturing area.

E-Learning Lessons from the Corporate World

2011 ◽  
pp. 514-531
Author(s):  
Geoffrey Dick ◽  
Tom Case ◽  
Craig Van Slyke
Keyword(s):  
Online Learning ◽  
Human Resource Management ◽  
Human Resource ◽  
Learning Systems ◽  
Academic World ◽  
Learning Modules ◽  
Corporate World ◽  
E Learning

This chapter examines the development of online learning systems, how they incorporate reusable learning modules and how various forms of assessment are employed to improve the quality of the learning outcomes. Corporations are adopting online learning, or e-learning, at a dramatic rate, partly driven by a desire for cost reduction and partly to ensure that all staff have the required skills and ability to their jobs. Organizations are increasingly linking the systems for delivery of this learning into human resource management systems. Universities, despite some movement to e-learning are in a position to learn form the developments in the corporate world. A case study is used to illustrate many of the concepts discussed. In conclusion, the chapter suggests how these corporate experiences might be transferred into the academic world and sounds a note of warning for the universities if they fail to match the corporate offerings.

scholarly journals Formalizing Manufacturing Process Modeling Using Composition Trees

2011 ◽  
Vol 399-401 ◽  
pp. 1852-1855 ◽  
Author(s):  
Lian Wen ◽  
David Tuffley
Keyword(s):  
Process Modeling ◽  
Manufacturing Process ◽  
Good Effect ◽  
Software Systems ◽  
Manufacturing Processes ◽  
Modeling Languages ◽  
Tree Model ◽  
Short Period

Optimizing manufacturing process modeling is critical to improving the efficiency and quality of manufacturing. However, manufacturing processes in general can be very complicated. A manufacturing process may involve (a) transforming a material into a new form, (b) combining different materials to form a new object, and (c) retrieving a certain part from a material as a new entity. All those activities could be confusing because many intermediate objects that exist only for a short period during the manufacturing process may have no formal names. To solve this problem, this paper proposes that composition trees (CT) can be successfully used to model manufacturing processes. Composition trees are parts of the formal notation in behavior engineering (BE), which is an innovative approach to the development of large software systems. For a composition tree, its characteristics of being intuitive, expressive and formal give it many advantages over other formal and informal modeling languages in software engineering. This paper uses a cooking case study to demonstrate how to use a composition tree model manufacturing processes. It is argued that the method could be applied to process engineering to good effect.

Numerical approaches and experimental verification of the conical indentation techniques for residual stress evaluation

2010 ◽  
Vol 25 (11) ◽  
pp. 2212-2223 ◽  
Author(s):  
Jin Haeng Lee ◽  
Hyungyil Lee ◽  
Hong Chul Hyun ◽  
Minsoo Kim
Keyword(s):  
Residual Stress ◽  
Material Properties ◽  
Compressive Residual Stress ◽  
Plasticity Theory ◽  
Bending Stress ◽  
Stress Evaluation ◽  
Four Point Bending ◽  
Indentation Methods ◽  
Numerical Approaches ◽  
Conical Indentation

Conical indentation methods to determine residual stress are proposed by examining the finite element solutions based on the incremental plasticity theory. We first note that hardness depends on the magnitude and sign of residual stress and material properties and can change by up to 20% over a specific range of elastic tensile and compressive residual stress, although some prior indentation studies reported that hardness is hardly affected by residual stress. By analyzing the characteristics of conical indentation, we then select some normalized indentation parameters, which are free from the effect of indenter tip rounding. Adopting dimensional analysis, we present practical conical indentation methods for the evaluation of elastic/plastic equi- and nonequi-biaxial residual stresses. The validity of developed approaches is confirmed by applying them to the experimental evaluation of four-point bending stress.

Material Loadings during Electrochemical Machining (ECM) - A First Step for Process Signatures

2015 ◽  
Vol 651-653 ◽  
pp. 695-700 ◽  
Author(s):  
Fritz Klocke ◽  
Simon Harst ◽  
Lisa Ehle ◽  
Markus Zeis ◽  
Andreas Klink
Keyword(s):  
Residual Stress ◽  
Material Properties ◽  
Manufacturing Process ◽  
Electrochemical Machining ◽  
State Variables ◽  
Change Of State ◽  
Working Principle ◽  
Specific Material ◽  
Manufacturing Technologies ◽  
The Individual

Properties of workpieces, like residual stress in the rim zone, cannot be predicted for manufacturing technologies reproducible in advance. This lack of predictability shall be solved by a new approach, called Process Signatures. These Process Signatures will combine the material loadings forced by the manufacturing process with the change of state variables, e. g. the variation of residual stress in the surface layer. As the Process Signatures shall achieve comparability for different processes with same physical working principle, it is necessary to describe the transition from material loadings to the change of material properties in a uniform way. Consequently an energy based approach is chosen that considers these transitions by the dissipation of the several kinds of energy brought into the manufacturing process and especially in the respective working area.A first step for the development of such Process Signatures is the identification of all process specific material loadings. This paper presents several material loadings generated during the electrochemical sinking process. In a further step the contribution of the individual material loadings to the material removal process are estimated. Finally first approaches for the combination of the main material loadings and the change of material properties are presented.

An Indentation Method Based on FEA for Equi-Biaxial Residual Stress Evaluation

2006 ◽  
Vol 326-328 ◽  
pp. 481-486
Author(s):  
Jin Haeng Lee ◽  
Hyung Yil Lee
Keyword(s):  
Residual Stress ◽  
Material Properties ◽  
Plasticity Theory ◽  
Indentation Method ◽  
Stress Evaluation ◽  
New Approach ◽  
Normalized Parameters ◽  
Tip Radius

An indentation method to determine equi-biaxial residual stress is proposed by examining the data from the incremental plasticity theory based FE analyses. We found that hardness is strongly dependent of the magnitude and sign of residual stress and material properties. We then selected some normalized parameters minimally affected by material properties and tip radius. With numerical regressions of the data obtained, we proposed new formulae for residual stress evaluation. The new approach provides a substantial enhancement in accuracy compared with the prior methods.

scholarly journals Opportunities and limitations: A comparative analysis of citizen science and expert recordings for bioacoustic research

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253763
Author(s):  
Denise Jäckel ◽  
Kim G. Mortega ◽  
Ulrike Sturm ◽  
Ulrich Brockmeyer ◽  
Omid Khorramshahi ◽  
...  
Keyword(s):  
Citizen Science ◽  
Quality Of Data ◽  
Academic World ◽  
Spectral Parameters ◽  
Scientific Curiosity ◽  
Academic Researchers ◽  
Citizen Science Project ◽  
Made In

Citizen science is an approach that has become increasingly popular in recent years. Despite this growing popularity, there still is widespread scepticism in the academic world about the validity and quality of data from citizen science projects. And although there might be great potential, citizen science is a rarely used approach in the field of bioacoustics. To better understand the possibilities, but also the limitations, we here evaluated data generated in a citizen science project on nightingale song as a case study. We analysed the quantity and quality of song recordings made in a non-standardized way with a smartphone app by citizen scientists and the standardized recordings made with professional equipment by academic researchers. We made comparisons between the recordings of the two approaches and among the user types of the app to gain insights into the temporal recording patterns, the quantity and quality of the data. To compare the deviation of the acoustic parameters in the recordings with smartphones and professional devices from the original song recordings, we conducted a playback test. Our results showed that depending on the user group, citizen scientists produced many to a lot of recordings of valid quality for further bioacoustic research. Differences between the recordings provided by the citizen and the expert group were mainly caused by the technical quality of the devices used—and to a lesser extent by the citizen scientists themselves. Especially when differences in spectral parameters are to be investigated, our results demonstrate that the use of the same high-quality recording devices and calibrated external microphones would most likely improve data quality. We conclude that many bioacoustic research questions may be carried out with the recordings of citizen scientists. We want to encourage academic researchers to get more involved in participatory projects to harness the potential of citizen science—and to share scientific curiosity and discoveries more directly with society.

Misophonia: An Evidence-Based Case Report

2020 ◽  
Vol 29 (4) ◽  
pp. 685-690
Author(s):  
C. S. Vanaja ◽  
Miriam Soni Abigail
Keyword(s):  
Quality Of Life ◽  
Case Report ◽  
Case History ◽  
Pure Tone ◽  
Physiological Responses ◽  
Evidence Based ◽  
Management Option ◽  
Pure Tone Audiogram

Purpose Misophonia is a sound tolerance disorder condition in certain sounds that trigger intense emotional or physiological responses. While some persons may experience misophonia, a few patients suffer from misophonia. However, there is a dearth of literature on audiological assessment and management of persons with misophonia. The purpose of this report is to discuss the assessment of misophonia and highlight the management option that helped a patient with misophonia. Method A case study of a 26-year-old woman with the complaint of decreased tolerance to specific sounds affecting quality of life is reported. Audiological assessment differentiated misophonia from hyperacusis. Management included retraining counseling as well as desensitization and habituation therapy based on the principles described by P. J. Jastreboff and Jastreboff (2014). A misophonia questionnaire was administered at regular intervals to monitor the effectiveness of therapy. Results A detailed case history and audiological evaluations including pure-tone audiogram and Johnson Hyperacusis Index revealed the presence of misophonia. The patient benefitted from intervention, and the scores of the misophonia questionnaire indicated a decrease in the severity of the problem. Conclusions It is important to differentially diagnose misophonia and hyperacusis in persons with sound tolerance disorders. Retraining counseling as well as desensitization and habituation therapy can help patients who suffer from misophonia.

Chronic Refractory Cough: A Case Study

2017 ◽  
Vol 2 (3) ◽  
pp. 57-62
Author(s):  
Anna Maria Siciliano
Keyword(s):  
Quality Of Life ◽  
Adult Female ◽  
Chronic Cough ◽  
Treatment Regime ◽  
Speech Language Pathology ◽  
Old Adult ◽  
Language Pathology

This paper presents a successful behavioral case study in treatment of chronic refractory cough in a 60-year-old adult female. The efficacy for speech-language pathology treating chronic cough is discussed along with description of treatment regime. Discussion focuses on therapy approaches used and the patient's report of changes in quality of life and frequency, duration, and severity reduction of her cough after treatment.

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