scholarly journals Determination of Hydrogen Transport Behaviour in Boron-Manganese Steels Using Different Methods and Boundary Conditions

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1007 ◽  
Author(s):  
Kuhlmann ◽  
Mitzschke ◽  
Jüttner
Keyword(s):  
Boundary Conditions ◽  
High Strength ◽  
Hydrogen Transport ◽  
Ministry Of Education ◽  
Electrolytic Coating ◽  
Test Methodology ◽  
Transport Behaviour ◽  
Constant Heating ◽  
Manganese Steels

Within the framework of the project "ELOBEV" (research of electrolytic coating systems for joining elements made of high-strength materials) funded by the Federal Ministry of Education and Research, a test methodology for the assessment of the danger of hydrogen-assisted and liquid metal-induced cracking for auxiliary joining elements is being developed. One working point of the project is the determination of the hydrogen transport behaviour in high-strength boron-manganese steels and their coating concepts. Permeation measurements under different boundary conditions are used to characterize the hydrogen transport in 22MnB5 and 37MnB4. The results are validated by thermal desorption analyses with a constant heating rate and an isothermal temperature control. Several methods for the determination of the diffusion velocity are investigated and the determined values are compared with each other.

Ermüdung von Schweißverbindungen höher- und hochfester warmgefertigter nahtloser Stahlbauhohlprofile MSH/Fatigue of Welded Connections at Hot Finished Higher Strength or High Strength Hollow Sections

Konstruktion ◽  
2018 ◽  
Vol 70 (01-02) ◽  
pp. 76-81
Author(s):  
Bernd Kranz ◽  
Jörg Herrmann ◽  
Ronny Baum ◽  
Boris Straetmans
Keyword(s):  
Fatigue Strength ◽  
Boundary Conditions ◽  
Fatigue Test ◽  
High Strength Steel ◽  
High Strength ◽  
Machine Construction ◽  
Hollow Section ◽  
Steel Grades ◽  
Additional Reference

Inhalt: Dauerfestigkeit geschweißter Hohlprofilkonstruktionen ist für viele Anwendungen im Maschinenbau relevant. Für Schweißverbindungen höher- und hochfester Hohl- profilwerkstoffe gibt es aber nur eine begrenzte Anzahl verfügbarer Angaben. Ziel der vorliegenden Untersuchung an drei höher- und hochfesten Werkstoffen ist die Ermittlung von Wöhlerlinien bei unterschiedlichen Verarbeitungsrandbedingungen. Konkret wurden dazu konventionelle MSG Schweißverbindungen an bauteilähnlichen Proben ohne und mit Nahtvorbereitung sowie mit Nahtvorbereitung und Vorwärmen hergestellt und Ermüdungsversuchen unterzogen. Konstrukteuren und Verarbeitern dienen diese als weitere Referenz zur optimalen Nutzung der vorgestellten Verbindungen und Werkstoffe.   Abtract: Fatigue strength of welded hollow section designs is relevant for many applications in machine construction. For welded connections of higher strength or high strength hollow sections only a limited amount of data is available. Objective of the present research on three higher strength or high strength steel grades is the determination of Wöhler curves for different boundary conditions for processing. In practice components of conventionally GMAW welded-connections had been manufactured, without weld preparation, with weld preparation and with weld preparation and preheating – subsequently a fatigue test was done. Results serve designers and manufacturers as additional reference for optimized use of the presented joints and steel grades.

The Validity of Rector�s Circular Letter on the Covid-19 Pandemic

2020 ◽  
Vol 7 (1) ◽  
pp. 126 ◽  
Author(s):  
Fradhana Putra Disantara
Keyword(s):  
Legal Theory ◽  
Legal Issues ◽  
State Universities ◽  
Ministry Of Education ◽  
Conceptual Approach ◽  
State Of Emergency ◽  
Circular Letter ◽  
The Status ◽  
The Government

This study aims to analyze the relevance of the �health emergency� status to the existing legal theory and condition as well as to identify the validity of the Circular Letter of the Rector of State Universities. To this end, this study applied the statute and conceptual approach. The study was conducted by inventorying primary and secondary legal materials to obtain a proper and critical review of the legal issues under study. The results showed that the determination of the �health emergency� status by the government was inappropriate due to the uncertainty of the regulations issued by the government to determine the current condition. Thus, the status of the COVID-19 pandemic is a �legal emergency� status. Further, the Rector�s policy through the Circular Letter is valid judicially, sociologically, and philosophically. The determination of the �legal emergency� status can be done by issuing a Perppu without a �state of emergency� from the President. Finally, it is suggested to firstly get an approval from the Ministry of Education and Culture regarding the issuance of the Rector�s Circular Letter. Besides, further study is needed as this study was conducted during the COVID-19 pandemic.�Keabsahan Surat Edaran Rektor Perguruan Tinggi dalam Pandemi Covid-19Tujuan dari penelitian ini adalah untuk menganalisa relevansi status �darurat kesehatan� dengan teori hukum dan kondisi yang ada dan keabsahan atas Surat Edaran Rektor Perguruan Tinggi Negeri. Metode yang digunakan dalam penelitian ini adalah statute approach dan conseptual approach. Penelitian dilakukan dengan menginventarisasi bahan hukum primer dan sekunder, guna mendapatkan kajian yang seyogianya dan telaah kritis terkait isu hukum. Hasil penelitian menyatakan penetapan status darurat kesehatan oleh pemerintah kurang tepat, dikarenakan tidak menentu-nya peraturan yang dikeluarkan oleh pemerintah untuk menetapkan kondisi saat ini. Sehingga, status pandemi COVID-19 merupakan status darurat hukum. Kebijakan rektor melalui Surat Edaran adalah absah secara aspek yuridis, sosiologis, dan filosofis. Penetapan darurat hukum cukup dilakukan dengan menerbitkan Perppu tanpa pernyataan darurat dari Presiden. Saran peneliti adalah di perlukan persetujuan pada Kementerian Pendidikan dan Kebudayaan terkait terbitnya Surat Edaran Rektor, dan dibutuhkan penelitian lebih lanjut dikarenakan penelitian ini dilakukan pada masa COVID-19 yang bersifat temporal.�

TESTS COATINGS UNDER VARIABLE LOADS

2017 ◽  
pp. 95-98
Author(s):  
N. L. Venediktov ◽  
A. N. Venediktov ◽  
I. M. Kovenskiy
Keyword(s):  
Fatigue Testing ◽  
Laboratory Scale ◽  
Kinematic Scheme ◽  
Electrolytic Coating ◽  
Test Parameters ◽  
Experimental Laboratory

The experimental laboratory-scale plant for the fatigue testing of samples with electrolytic coating were designed and constructed. Shows the kinematic scheme and considered the principle of the plant. The dependences for determination of test parameters and the method of testing samples with coatings under variable loads were obtained.

Bestimmung der Dauerhaftigkeit von Hochleistungsbeton mit Hilfe des CDF-Tests / Determination of the durability of high performance concrete by means of CDF-test

1999 ◽  
Vol 5 (1) ◽  
pp. 29-40
Author(s):  
R. Krumbach ◽  
U. Schmelter ◽  
K. Seyfarth
Keyword(s):  
Frost Resistance ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Factors Influencing

Abstract Variable obsen>ations concerning frost resistance of high performance concrete have been made. The question arises which are the decisive factors influencing durability under the action of frost and de-icing salt. The proposed experiments are to be carried out in cooperation with F.A.- Finger - Institute of Bauhaus University Weimar. The aim of this study is to determine possible change of durability of high strength concrete, and to investigate the origin thereof. Measures to reduce the risk of reduced durability have to be found.

scholarly journals Stiffness Estimation and Equivalence of Boundary Conditions in FEM Models

2021 ◽  
Vol 11 (4) ◽  
pp. 1482
Author(s):  
Róbert Huňady ◽  
Pavol Lengvarský ◽  
Peter Pavelka ◽  
Adam Kaľavský ◽  
Jakub Mlotek
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Boundary Conditions ◽  
Model Updating ◽  
Element Model ◽  
Computational Time ◽  
Stiffness Coefficients ◽  
First Case ◽  
Numerical Approaches

The paper deals with methods of equivalence of boundary conditions in finite element models that are based on finite element model updating technique. The proposed methods are based on the determination of the stiffness parameters in the section plate or region, where the boundary condition or the removed part of the model is replaced by the bushing connector. Two methods for determining its elastic properties are described. In the first case, the stiffness coefficients are determined by a series of static finite element analyses that are used to obtain the response of the removed part to the six basic types of loads. The second method is a combination of experimental and numerical approaches. The natural frequencies obtained by the measurement are used in finite element (FE) optimization, in which the response of the model is tuned by changing the stiffness coefficients of the bushing. Both methods provide a good estimate of the stiffness at the region where the model is replaced by an equivalent boundary condition. This increases the accuracy of the numerical model and also saves computational time and capacity due to element reduction.

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