scholarly journals Quantitative Weld Quality Acceptance Criteria: An Enabler for Structural Lightweighting and Additive Manufacturing

2020 ◽  
Vol 99 (2) ◽  
pp. 39s-51s ◽  
Author(s):  
PINGSHA DONG ◽  
Keyword(s):  
Additive Manufacturing ◽  
Structural Integrity ◽  
Weld Quality ◽  
Fitness For Purpose ◽  
Lightweight Construction ◽  
Acceptance Criteria ◽  
Analysis Techniques ◽  
Recent Developments ◽  
Research Findings ◽  
Similar Materials

Most of the existing weld quality acceptance criteria stipulated in various codes and standards, as well as in recommended practices, are empirical in nature. Historically, these workmanship-based criterias have been adequate for quality control purposes in construction of welded structures. However, as the competition for achieving structural lightweighting intensifies, more quantitative quality acceptance (also known as fitness-for-purpose based) criteria are increasingly called for. This is because various new forms of discontinuities and joint configurations (e.g., dis-similar materials joints) cannot be readily related to existing acceptance criteria. Even if existing criteria can be made applicable, recent research findings have shown that existing criteria can be excessively conservative for some and unconservative for others when dealing with thin gauge and lightweight construction. A similar situation exists for additively manufactured metallic components, which can be viewed as “all weld metal” components containing randomly distributed discontinuities over the entire component volume. In this paper, some of the recent developments in quantitative weld quality acceptance criteria will be first highlighted, some of which are made possible by advanced fracture mechanics analysis techniques. Applications in structural lightweighting and additive manufacturing will then be demonstrated with some real-world examples. Finally, implications on a broader application of the methodologies presented for ensuring both structural integrity and cost-effectiveness in construction will be discussed in light of these developments.

scholarly journals Wire Arc Additive Manufacturing: Review on Recent Findings and Challenges in Industrial Applications and Materials Characterization

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 939
Author(s):  
Mukti Chaturvedi ◽  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Luigi Renato Mistodie ◽  
Danut Mihailescu ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Structural Integrity ◽  
Industrial Applications ◽  
Raw Material ◽  
Continuous Increase ◽  
Control Optimization ◽  
Modern Manufacturing ◽  
Directed Energy ◽  
Manufacturing Technologies ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) is a fusion manufacturing process in which the heat energy of an electric arc is employed for melting the electrodes and depositing material layers for wall formation or for simultaneously cladding two materials in order to form a composite structure. This directed energy deposition-arc (DED-arc) method is advantageous and efficient as it produces large parts with structural integrity due to the high deposition rates, reduced wastage of raw material, and low consumption of energy in comparison with the conventional joining processes and other additive manufacturing technologies. These features have resulted in a constant and continuous increase in interest in this modern manufacturing technique which demands further studies to promote new industrial applications. The high demand for WAAM in aerospace, automobile, nuclear, moulds, and dies industries demonstrates compatibility and reflects comprehensiveness. This paper presents a comprehensive review on the evolution, development, and state of the art of WAAM for non-ferrous materials. Key research observations and inferences from the literature reports regarding the WAAM applications, methods employed, process parameter control, optimization and process limitations, as well as mechanical and metallurgical behavior of materials have been analyzed and synthetically discussed in this paper. Information concerning constraints and enhancements of the wire arc additive manufacturing processes to be considered in terms of wider industrial applicability is also presented in the last part of this paper.

Structural Integrity for Nuclear Power Plant Against Excessive Load on Design Extension Condition

2013 ◽  
Author(s):  
Daigo Watanabe ◽  
Kiminobu Hojo
Keyword(s):  
Nuclear Power ◽  
Structural Integrity ◽  
Safety Factors ◽  
Design Code ◽  
Acceptance Criteria ◽  
Integrity Assessment ◽  
Current Design ◽  
Factor Design ◽  
Excessive Load ◽  
Load And Resistance Factor

This paper introduces an example of structural integrity evaluation for Light Water Reactor (LWR) against excessive loads on the Design Extension Condition (DEC). In order to assess the design acceptance level of DEC, three acceptance criteria which are the stress basis limit of the current design code, the strain basis limit of the current design code and the strain basis limit by using Load and Resistance Factor Design (LRFD) method were applied. As a result the allowable stress was increased by changing the acceptance criteria from the stress basis limit to the strain basis limit. It is shown that the practical margin of the LWR’s components still keeps even on DEC by introducing an appropriate criterion for integrity assessment and safety factors.

scholarly journals Hierarchical ordering in light-triggered additive manufacturing

2020 ◽  
Vol 11 (46) ◽  
pp. 7316-7329
Author(s):  
Joël Monti ◽  
Eva Blasco
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Future Prospects ◽  
Structural Hierarchy ◽  
Recent Developments ◽  
Hierarchical Ordering

Herein, recent developments in the 3D printing of materials with structural hierarchy and their future prospects are reviewed. It is shown that increasing the extent of ordering, is essential to access novel properties and functionalities.

Recent Developments of the Multiphysics Discrete Element Method for Additive Manufacturing Modeling and Simulation

2017 ◽  
Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos
Keyword(s):  
Additive Manufacturing ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Additive Manufacture ◽  
Computational Tools ◽  
Computational Performance ◽  
Macro Scale ◽  
Recent Developments ◽  
Am Processes ◽  
Element Method

Recent years have seen a sharp increase in the development and usage of Additive Manufacturing (AM) technologies for a broad range of scientific and industrial purposes. The drastic microstructural differences between materials produced via AM and conventional methods has motivated the development of computational tools that model and simulate AM processes in order to facilitate their control for the purpose of optimizing the desired outcomes. This paper discusses recent advances in the continuing development of the Multiphysics Discrete Element Method (MDEM) for the simulation of AM processes. This particle-based method elegantly encapsulates the relevant physics of powder-based AM processes. In particular, the enrichment of the underlying constitutive behaviors to include thermoplasticity is discussed, as are methodologies for modeling the melting and re-solidification of the feedstock materials. Algorithmic improvements that increase computational performance are also discussed. The MDEM is demonstrated to enable the simulation of the additive manufacture of macro-scale components. Concluding remarks are given on the tasks required for the future development of the MDEM, and the topic of experimental validation is also discussed.

scholarly journals LITERASI INFORMASI PENGELOLA KOMUNITAS SAHABAT ILMU JAMBI BERDASARKAN STANDAR IFLA

2019 ◽  
Vol 25 (2) ◽  
pp. 145-163
Author(s):  
Rio Gusma Hendra ◽  
Wenny Dastina ◽  
Muhammad Rum
Keyword(s):  
Mobile Phones ◽  
Research Method ◽  
Information Needs ◽  
Sources Of Information ◽  
Data Presentation ◽  
Analysis Techniques ◽  
Internet Media ◽  
Research Findings ◽  
Descriptive Approach ◽  
Access Information

This study aims to determine how the ability of Jambi Friends of the Community of Friends in accessing, evaluating and using information. This study uses a qualitative research method with a descriptive approach and data collection through observation, interviews, and documentation. Data analysis techniques used: data reduction, data presentation, drawing conclusions and data triangulation. Based on the results of the analysis and research findings, the ability of the Jambi Sahabat Community Community Managers to access information based on the IFLA standard is said to be Expert, because it is seen from the manager’s ability to define information needs and to trace information through various sources, such as people who are experts in their fields, from print media: books and newspapers, electronic media: television and mobile phones. The ability of the Friends of the Jambi Friends of the Community in evaluating information based on the IFLA standard is said to be Expert, because it is seen from the ability of the manager to assess information and manage information obtained through clear sources of information, such as books, and internet media, as well as sources from internal community discussions. The ability of the Jambi Friends of the Sahabat Community Community to use information based on the IFLA standard can be said to be Expert, seen from the manager’s ability to use information and communicate information directly in the form of discussion, and indirectly as well as convey information with a simpler and easier to understand delivery

scholarly journals ANALISIS EKOLOGI BERWAWASAN GENDER (ECOFEMINISM) DALAM KARYA SASTRA PARA SASTRAWAN LAMONGAN

2019 ◽  
Vol 11 (2) ◽  
pp. 80-85
Author(s):  
Kiki Astrea ◽  
Anisa Ulfah
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Literary Text ◽  
Data Sources ◽  
Data Validation ◽  
Analysis Techniques ◽  
Social Ecological ◽  
Ecological Values ◽  
Research Findings ◽  
Cultural Ecological

The purpose of this study is the discovery of (1) the influence of political ecological values (2) the influence of cultural ecological values (3) the influence of social ecological values, and (4) the influence of the ecological values of imperialism heritage. The data in this study are data about (1) the influence of political ecological values  (2)  The  influence  of  cultural  ecological  values  (3)  The  influence  of  social ecological values, and (4) the influence of the ecological values of imperialism heritage. Data sources are obtained from documentation and interviews. The data collection techniques are carried out with documentation and interviews. Data analysis techniques use interactive techniques. Data validation uses triangulation, both triangulation of theories, data, and methods. The research findings can be described include: (1) the influence of political ecological values (2) The influence of cultural ecological values (3) The influence of social ecological values, and (4) the influence of the ecological values of imperialism inheritance in the literary text writer in Lamongan

scholarly journals Preface

2021 ◽  
Vol 904 (1) ◽  
pp. 011001
Keyword(s):  
Peer Review Process ◽  
Evaluation Process ◽  
College Of Agriculture ◽  
Double Blind ◽  
The World ◽  
Recent Developments ◽  
New Ideas ◽  
Research Findings ◽  
Combating Desertification ◽  
Desert Regions

The ICDS conference intends to bring together junior and senior, international and national researchers, scientists and scholars interesting in the field of desertification combat and water harvesting in desert regions. We think the conference will offer an excellent opportunity for networking with other members and exchange knowledge and explore the most recent developments in the desertification combat such as Water Resources Management in Desert Regions, Ecosystem and Biodiversity of Desert, Geology and Remote Sensing for Combating Desertification, Recent Agricultural Techniques Serving in Desert Soil Management, and Desert Regions Exploitation for Agricultural Production Regards. ICDS-2021 is a prestigious event organized by the Center of Desert Studies in cooperation with the College of Agriculture, University of Anbar, with a motivation to provide an excellent international platform for academicians, researchers, engineers, industrial participants and budding students around the world to share their research results with the global experts. We cordially invited participants from all over the world who wish to share their best practices and research findings in ICDS-2021 and enlighten their new ideas to make this event growing from strength to strength. Participants will be offered the opportunity to contribute to the conference in various roles: they can discuss keynotes, produce a poster presentation and submit full research or review articles. Articles submitted to the conference should report original high-quality and previously unpublished results. Submission of a manuscript implies that it is not under consideration for publication elsewhere. All submitted articles will be subjected to a double-blind peer-review process. Novelty, relevancy, language standards, references, and many other factors are considered for the evaluation process. The conference nominated Prof. Dr. Prof. Dr. Amir Ibrahim (College of Agriculture & Life Science Texas A&M University, U.S.), Prof. Dr. Medhat M. Elsahookie (College of Agriculture, University of Baghdad, Iraq), and Prof. Dr. Wadid Erian (Faculty of Agriculture, Cairo University, Egypt) as keynote speakers. ICDS-2021 will be held basically via physical attendance (In-person) for two days 17-18 November, 2021 in Ramadi, Anbar, Iraq. Each participant will be given approximately 10 minutes to view the most important findings of his/her research, and 5 minutes to discuss these results. Sincerely yours, Prof. Dr. Nihad Mohammed Aboud Director of the Center of Desert Studies/University of Anbar The Chairman of ICDS-2021 List of Committees (ICDS-2021) are available in this pdf.

scholarly journals A Study on Adapting of Afghan Students in Universities of Turkey

2018 ◽  
Vol 6 (10) ◽  
Author(s):  
Ahmad Jawid Muradi ◽  
Ismet BOZ ◽  
Mirwas AZAMI
Keyword(s):  
Interpersonal Relationships ◽  
Cultural Adaptation ◽  
Sampling Method ◽  
Primary Data ◽  
Nonparametric Analysis ◽  
Educational Levels ◽  
Analysis Techniques ◽  
Turkish Government ◽  
Research Findings ◽  
Online Sampling

The aim of the study is to propose a solution by examining the adaptation problems experienced by the Afghan students who are studying in different faculties and departments of various universities of Turkey. The survey based on the primary data collected by online sampling method and 60 different questions from Afghan students studying in Turkey by August 2017. In the analysis of the obtained data, SPSS version 21.0 program was used and parametric and nonparametric analysis techniques applied in the direction of research findings. The survey has been done in 49 various universities, 12 different faculties, and 161 students. Among the participants 39.1% had scholarships from the Turkish government (YTB), 26.7% were supported by the Afghanistan government, and 34.2% were studying by their own financial possibilities. All of the students came from Afghanistan for education purposes. Their parents' economic and educational levels are good; nearly all of them are well-educated people. Most of the students are living in dormitories, and they are happy to study in Turkey. They don't have any problems with interpersonal relationships and cultural adaptation with other students in dorms, as well as with people in Turkey.

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