Applying Path Planning to the Design of Additively Manufactured Functionally Graded Materials

2018 ◽  
Author(s):  
Tanner Kirk ◽  
Richard Malak ◽  
Raymundo Arroyave
Keyword(s):  
Functionally Graded ◽  
Future Research ◽  
Graded Materials ◽  
Functionally Gradient ◽  
Path Design ◽  
And Performance ◽  
Cr System ◽  
Parameter Dependency ◽  
Infinite Set

Additive manufacturing has enabled the creation of a near infinite set of functionally gradient materials. One limitation on the manufacturability and usefulness of these materials is the presence of undesirable phases along the gradient path. For example, such phases may increase brittleness, diminish corrosion resistance, or severely compromise the printability of the part altogether. In the current work, a design methodology is proposed to plan an FGM gradient path for any number of elements that avoids undesirable phases at a range of temperatures. Gradient paths can also be optimized for a cost function. A case study is shown to demonstrate the effectiveness of the methodology in the Fe-Ni-Cr system. Paths were successfully planned from 316L SS to pure Cr that either minimize path length or maximize separation from undesirable phases. Examinations on the stochastic variability, parameter dependency, and computational efficiency of the method are also presented. Several avenues of future research are proposed that could improve the manufacturability, utility, and performance of FGMs through gradient path design.

scholarly journals Computational Design of Gradient Paths in Additively Manufactured Functionally Graded Materials

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Tanner Kirk ◽  
Edgar Galvan ◽  
Richard Malak ◽  
Raymundo Arroyave
Keyword(s):  
Functionally Graded Materials ◽  
Computational Design ◽  
Functionally Graded ◽  
Future Research ◽  
Graded Materials ◽  
316 L Stainless Steel ◽  
And Performance ◽  
Cr System ◽  
Parameter Dependency ◽  
Stainless Steel 316

Additive manufacturing (AM) has enabled the creation of a near infinite set of functionally graded materials (FGMs). One limitation on the manufacturability and usefulness of these materials is the presence of undesirable phases along the gradient path. For example, such phases may increase brittleness, diminish corrosion resistance, or severely compromise the printability of the part altogether. In the current work, a design methodology is proposed to plan an FGM gradient path for any number of elements that avoids undesirable phases at a range of temperatures. Gradient paths can also be optimized for a cost function. A case study is shown to demonstrate the effectiveness of the methodology in the Fe–Ni–Cr system. Paths were successfully planned from 316 L Stainless Steel (316 L SS) to pure Cr that either minimize path length or maximize separation from undesirable phases. Examinations on the stochastic variability, parameter dependency, and computational efficiency of the method are also presented. Several avenues of future research are proposed that could improve the manufacturability, utility, and performance of FGMs through gradient path design.

Pitch Error Coding the Sight Read, Practice, and Performance of an Elite Oboist

2016 ◽  
Vol 34 (2) ◽  
pp. 132-151
Author(s):  
Deborah L. E. de Graaff ◽  
Emery Schubert
Keyword(s):  
Cognitive Theory ◽  
Schema Theory ◽  
Future Research ◽  
Sight Reading ◽  
Reading Practice ◽  
Pitch Error ◽  
Error Coding ◽  
And Performance ◽  
Better Than

This paper presents a developing Pitch Error Coding Protocol for assessing the accuracy of a musician’s performance. The protocol organized performance errors into any of three main categories, each based on an established cognitive theory of music memory and processing: (1) the Serial Distance Hypothesis (SDH); (2) the Implication Realization (I-R) model; and (3) the mental organizing principle of the Schema Theory (SCH). An elite oboist formed the basis of a detailed case study where his sight reading, practice, and performance of a challenging excerpt of music were examined. These data were used to: 1) investigate the protocol; 2) ask whether any protocol components could explain errors better than others; 3) and show where improvements after practice occurred. The results revealed that the SDH accounted for the majority of pitch errors, these originated in a three-note proximity of the target and some SDH errors overlapped with the I-R category errors. Although final counts for SDH and I-R are similar, SDH uniquely identified errors more frequently than the I-R. Future research and development of the protocol might look at combinations of pieces and performer to determine whether SDH may be a dominant source of error.

scholarly journals Thermo-Elastic Analysis Of A Rotating Hollow Cylinder Made Of Arbitrary Functionally Graded Materials

2015 ◽  
Vol 45 (4) ◽  
pp. 41-60
Author(s):  
Mohammad Arefi ◽  
Iman Nahas ◽  
Majid Abedi
Keyword(s):  
Radial Displacement ◽  
Mechanical Analysis ◽  
Functionally Graded ◽  
Mechanical And Thermal Properties ◽  
Elastic Analysis ◽  
Graded Materials ◽  
Hollow Structures ◽  
Study Power ◽  
Rotating Hollow Cylinder

AbstractThermo-mechanical analysis of the functionally graded orthotropic rotating hollow structures, subjected to thermo-mechanical loadings is studied in this paper. The relations were derived for both plane strain and plane stress conditions as a cylinder and disk, respectively. Non homogeneity was considered arbitrary through thickness direction for all mechanical and thermal properties. The responses of the system including temperature distribution, radial displacement and radial and circumferential stresses were derived in the general state. As case study, power law gradation was assumed for functionally graded cylinder and the mentioned results were evaluated in terms of parameters of the system such as non-homogeneous index and angular velocity.

Knowledge Assets in the Global Economy

2001 ◽  
pp. 232-249 ◽  
Author(s):  
Yogesh Malhotra
Keyword(s):  
Global Economy ◽  
Resource Planning ◽  
Assessment Methods ◽  
Information Resource ◽  
Future Research ◽  
National Economic ◽  
Assessment Techniques ◽  
And Performance ◽  
National Information

This chapter has the following objectives: developing the need for assessing knowledge capital at the national economic level; reviewing a national case study of how intellectual capital assessment was done in case of one nation state; suggesting implications of use of such assessment methods and needed areas of advancement; and highlighting caveats in existing assessment methods that underscore the directions for future research. With increasing emphasis on aligning national information resource planning, design and implementation with growth and performance needs of business or nation, better understanding of new valuation and assessment techniques is necessary for information resource management policymakers, practitioners and researchers.

Functionally Gradient Materials

MRS Bulletin ◽  
1995 ◽  
Vol 20 (1) ◽  
pp. 14-18 ◽  
Author(s):  
B.H. Rabin ◽  
I. Shiota
Keyword(s):  
Gas Turbines ◽  
Functionally Gradient Materials ◽  
Graded Materials ◽  
Ongoing Research ◽  
Engineering Construction ◽  
Gradient Materials ◽  
Performance Requirements ◽  
Research Activities ◽  
Functionally Gradient ◽  
And Performance

This issue of the MRS Bulletin provides an up-to-date look at ongoing research activities within the field of functionally gradient materials (FGM). The term FGM, now widely used by the materials community, originated in Japan in the late 1980s as a description for a class of engineering materials exhibiting spatially inhomogeneous microstructures and properties. Of course, gradient materials are not something new. It must be recognized that humans have extensively utilized materials containing microstructural gradients (either those found in nature or those created through processing) since the earliest days of craftsmanship and engineering construction. Indeed, there are examples of graded materials developed long ago, such as case-hardened steel, which are still in common use today. Contemporary examples of these materials serve in technologically significant applications, as, for example, in thermal-barrier coatings for gas turbines. Nevertheless, what is new and exciting about FGMs is the realization that gradients can be designed at the microstructural level to tailor a material for the specific functional and performance requirements of an intended application. In addition, recent advances in processing are opening the possibility for the extension of the gradient materials concept to new materials systems and engineering problems.The recent resurgence of interest in gradient materials has been driven by the need for improved materials, capable of meeting the demanding performance requirements established by emerging technologies such as the aerospace plane, ceramic engines, and nuclear fusion.

scholarly journals Custo financeiro da estocagem: estudo de caso em indústria de grande porte

2018 ◽  
Vol 17 (1) ◽  
pp. 79-102
Author(s):  
Rodney Wernke ◽  
Andrey Pereira dos Santos ◽  
Lia Schlickmann ◽  
Antonio Zanin
Keyword(s):  
Raw Materials ◽  
Qualitative Approach ◽  
Future Research ◽  
Financial Cost ◽  
Financial Costs ◽  
And Performance ◽  
Long Storage ◽  
Study Format

Resumo: Neste artigo objetivou-se a mensuração dos custos financeiros relacionados à estocagem de matérias-primas de uma fábrica de grande porte. Para tanto, foi utilizada metodologia do tipo descritiva, com abordagem qualitativa e o formato de estudo de caso. Quanto aos resultados, no conjunto de 261 matérias-primas estocadas (que superava R$ 5,3 milhões) foram aplicados os procedimentos detalhados no texto que proporcionaram informações gerenciais acerca do valor elevado dos estoques excedentes (R$ 1.029.913,26), da existência de insumos com prazos de estocagem extensos e de custos financeiros expressivos (superiores a R$ 170 mil) pela manutenção de estoque com tais características. Além disso, foi possível determinar os produtos mais problemáticos e o desempenho por grupos de matérias-primas, permitindo a comparação entre essas modalidades de segregação. Por último, foram elencadas algumas limitações do estudo e recomendados temas para futuras pesquisas.Palavras-chave: Custo financeiro. Estoque. Estudo de caso. Financial cost of storage: a case study in a large industry Abstract: The article aimed at the measurement of financial costs related to the storage of raw materials of a large factory. For that, a descriptive methodology was used, with a qualitative approach and the case study format. As to the results, the procedures detailed in the text that provided managerial information about the high value of surplus inventories (R$ 1.029.913, 26), the existence of inputs with long storage periods and significant financial costs (over R$ 170 thousand) for the maintenance of inventory with such characteristics. In addition, it was possible to determine the most problematic products and performance by groups of raw materials, allowing a comparison between these segregation modalities. Finally, some limitations of the study and recommended topics for future research were listed.Keywords: Financial cost. Stock. Case study.

Thermoelastic Crack Analysis in Functionally Graded Pipelines Conveying Natural Gas by an FEM

2018 ◽  
Vol 10 (04) ◽  
pp. 1850036 ◽  
Author(s):  
Mohamed A. Attia ◽  
Mohamed A. Eltaher ◽  
Ahmed Soliman ◽  
Alaa A. Abdelrahman ◽  
Amal E. Alshorbagy
Keyword(s):  
Natural Gas ◽  
Surface Hardness ◽  
Element Model ◽  
Functionally Graded ◽  
Coupled Analysis ◽  
Graded Materials ◽  
Steel Material ◽  
Pressurized Fluids ◽  
Present Case Study

Internal cracks are a serious problem in pipelines conveying unsteady pressurized fluids like natural gas. To investigate and overcome this problem, this paper is motivated to highlight and study the response of gas pipes made of functionally graded materials (FGM) instead of the traditional carbon steel material. FGM is proposed as a composite material because of its advantages of minimizing the stress variation in the pipe. Ceramic is applied because of its durability against corrosion and its surface hardness against erosion. FGM properties are radially graded and a finite element model is developed and implemented into ABAQUS package, including FORTRAN subroutines which are adapted for the present case study. Coupled plane strain thermoelastic analysis is used to investigate the stresses and the stress intensity factor (SIF) at various crack depths under the actual thermomechanical loads. Both coupled and uncoupled thermomechanical approaches are introduced and compared to reveal the necessity of the coupled analysis for accurate FGMs’ investigation. The different influences of unsteady thermal and mechanical loads on the crack propagation are discussed.

Knowledge Assets in the Global Economy

2002 ◽  
pp. 329-345 ◽  
Author(s):  
Yogesh Malhotra
Keyword(s):  
Global Economy ◽  
Resource Planning ◽  
Assessment Methods ◽  
Information Resource ◽  
Future Research ◽  
National Economic ◽  
Assessment Techniques ◽  
And Performance ◽  
National Information

This article has the following objectives: to develop the need for assessing knowledge capital at the national economic level; to review a national case study of how intellectual capital assessment was done in the case of one nation state; to suggest implications of use of such assessment methods and needed areas of advancement; and highlight caveats in existing assessment methods that underscore the directions for future research. With increasing emphasis on aligning national information resource planning, design, and implementation with growth and performance needs of businesses or nations, better understanding of new valuation and assessment techniques are necessary for information resource management policymakers, practitioners, and researchers.

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