bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic Softening Behaviour of a Duplex Stainless Steel
Authors: Evrard Pierre , Aubin Véronique , Degallaix-Moreuil Suzanne , Kondo Djimedo , Alvarez-Armas Iris 
Published: December 2013

Abstract
This second part aims to propose an extension of the bi-phased polycrystalline model shown in a previous contribution [1], in order to simulate the cyclic softening observed in an austenitic-ferritic stainless steel under uniaxial and non-proportional biaxial cyclic loading [2]. Assuming that the cyclic softening for uniaxial and biaxial non-proportional cyclic loading is due to a rearrangement of dislocations in hard (rich in dislocations) and soft (poor in dislocations) zones in ferritic grains [3], the ferritic single crystal law is modified. The new model parameters are identified from TEM observations [3] and by inverse procedure. Finally, the new model is validated for other cyclic loading paths. A good agreement is observed between simulation and experimental data.
Stress Analyses Around Holes of Plates for Different Types of Materials
Authors: Hedia Hassan S. , Najjar Ismail M. R. , Elmidany Tawfik T. , Kamel Madiha M. 
Published: December 2013

Abstract
Among the most important elements in aircraft structures are joints for transferring loads. An accurate assessment of the stresses for joints is essential for reliable strength evaluation and failure prediction. The aim of this work is to compare different types of materials, i.e. isotropic, laminated, and functionally graded materials (FGM), and different types of laminates, considering the ratio of stresses generated around a hole in a plate and the applied stress. The finite element method (FEM) is used to evaluate the stresses around a hole for the three types of materials when the plate is subjected to tensile stress, heating, and both heating and tensile stress. Utilizing the ANSYS package, the target of the study was to investigate the validity of the method. The results obtained for the laminated plate are compared to those obtained by E. Pan, and Rybiki & Hopper for both (90/0)s and (—45/45)s laminates. By similar results, it was shown that the laminates can withstand loads better than isotropic materials or FGM.
Optimal Material Distribution of a Micro-Gripper Manipulator with Straight-Line Path and Parallel Movements
Authors: Helal Mahmoud , Sun Lining , Chen Liguo 
Published: December 2013

Abstract
Micro electro-mechanical systems (MEMS) are miniaturized devices that consist of both mechanical and electrical parts. Compliant mechanisms have made an enormous contribution in the design process of various fields such as adaptive structures, hand-held tools, components in transportations, electronics and medical tools. The use of compliant mechanisms will help in reducing the number of components, as a result decreasing manufacturing cost and increasing the performance. The topology optimization methods search for an ideal material distribution of a structure. In this investigation, a new two-dimensional micro-grippers compliant mechanism, which can realize a straight-line path and parallel movement arms, are developed. Material models, which parameterize stiffness and density properties, are implemented based on the well-known solid isotropic materials with penalization model. Optimality criteria method is applied as the optimization algorithm using the ANSYS package. The micro-grippers with compliant mechanism can be applied to targets with a diameter of up to 400 μm.
Influence of Tool Geometry on Microstructure and Mechanical Properties of a Friction Stir Welded 7075 Aluminum Alloy
Authors: Sayer Sami , Yeni Qinar 
Published: December 2013

Abstract
The effectiveness of a friction stir welded joint is strongly dependent on several process parameters such as the tool geometry, including the height and the shape of the pin and the shoulder surface of the tool. In this study, two pin parameters, namely the pitch dimension (1.25 and 0.75 mm) and the helix angle (right and left helices), are varied in order to study their influence on the micro-structural, hardness, and tensile properties of friction stir welded 6 mm thick aluminum alloy 7075. The results reveal that the best combination has been obtained when welding with a pitch dimension of 0.75 mm using a right helix pin.
Uncertainty Estimation of Coating Thickness Measurement Results
Authors: Runje Biserka , Baršić Gorana , Alar Željko 
Published: December 2013

Abstract
This contribution presents an estimation of the measurement uncertainty of coating thickness measurement results. The measurements were performed on a steel sheet sample with an outside shell plating. The sample is protected against corrosion with two layers of 100 ¼m thick dry film. In the present case, the criteria of “80-20” have been applied. The measurement uncertainty evaluation has been carried out using Monte Carlo simulations (MCS method) in accordance with the document OIML G 1-101 Edition 2008 (E) Evaluation of Measurement Data – Supplement 1 to the Guide to the Expression of Uncertainty in Measurement – Propagation of Distributions Using a Monte Carlo Method. The criteria “80-20” was evaluated based on the mean coating thickness measurement results, as well as, on the basis of the complete measuring information. Aside from the expected value, complete measuring information comprises the value of measurement uncertainty. In the case where measurement result is described only as the mean of the measurement values a wrong conclusion regarding the fulfillment “80-20” is reached.
Einfluss des Warmauslagerns auf das Gefüge sowie auf die mechanischen und tribologischen Eigenschaften eines Duplexstahles
Authors: Turhan Hüseyin 
Published: December 2013

Kurzfassung
Für den vorliegenden Beitrag wurde der Einfluss der Wärmebehandlung auf das Gefüge eines hochlegierten austenitisch-ferritischen Duplexstahles untersucht. Außerdem wurde der Einfluss des Homogenisierens und des Alterns auf das Werkstoffverhalten ermittelt. Die Proben wurden entsprechend ASME 1883 vorbereitet. Sie enthielten neben einem niedrigen Molybdängehalt höhere Kohlenstoff-, Chrom- und Nickelanteile. Nach dem Homogenisieren bei 1060 °C wurden die Proben der Reihe nach auf 475, 650 und 850°C erwärmt, bei diesen Temperaturen jeweils 80 h gealtert und danach in einem Eiswasserbad mit 3,5% NaCl rasch abgekühlt. Danach wurden das Gefüge und die mechanischen Eigenschaften des Werkstoffes untersucht. Bei den mechanischen Eigenschaften des Werkstoffes wurden viele und wichtige Unterschiede gefunden. Außerdem wurden alle Proben zur Bestimmung der intermetallischen Phasen und der Karbide lichtmikroskopisch, röntgenografisch und elektronenmikroskopisch untersucht. Aus den DTA-Kurven geht hervor, dass zwischen den Temperaturen von 1100 und 1221°C nur ein Umwandlungspeak existiert. Die ferritische und die austenitische Phase lösten sich in diesem Temperaturbereich auf und wandelten sich ausschließlich in Ferrit um.
Ein verbessertes Verfahren zur Lebensdauerabschätzung mittels linearer Schadensakkumulation
Authors: Hinkelmann Karsten , Esderts Alfons , Zenner Harald 
Published: December 2013

Kurzfassung
Ermüdungsfestigkeitsnachweise von Bauteilen werden häufig nach dem Nennspannungskonzept bzw. dem örtlichen Spannungskonzept geführt. Einen zentralen Punkt dieser Konzepte bildet die lineare Schadensakkumulation nach Palmgren und Miner (Miner-Regel). Statistische Auswertungen zeigen, dass die Lebensdauerabschätzung nach der linearen Schadensakkumulation im Mittel auf der unsicheren Seite liegt und eine höhere Treffsicherheit wünschenswert ist. Durch die Anwendung effektiver Schadenssummen kann die mittlere Lebensdauerüberschätzung korrigiert werden. Im Einzelfall kann es dennoch zu größeren Abweichungen zwischen Rechnung und Versuch kommen.
Zur Verbesserung der Lebensdauerabschätzung mittels linearer Schadensakkumulation werden zwei Lebensdauerkorrekturverfahren vorgestellt. Die Anpassung der rechnerischen Gaßnerlinie an Versuchsergebnisse erfolgt in Abhängigkeit von der Kollektivform und der Wöhlerlinienneigung durch einen Lebensdauerkorrekturexponenten anstatt einer (multiplikativen) konstanten effektiven Schadenssumme. Neben der höheren Treffsicherheit wird der Übergang der Gaßnerlinie in die Wöhlerlinie für Rechteckkollektive sichergestellt.
Cellular Aluminium Foam Metal Production with Space Holder Particles
Authors: Ozer Gökhan , Güler Kerem Altug , Taslicukur Zeynep 
Published: December 2013

Abstract
Metal foams are a new class of materials with low densities and novel physical, mechanical, thermal, electrical, and acoustic properties. Aluminum foams especially show potential for use in lightweight structures, for energy absorption, and for thermal management. Open cell aluminum foams with tailored porous morphology were synthesized by a space-holder method. In these foams, the pore shape is predominantly controlled by the initial shape of the space-holder particles that are used to produce the preform. In this study, resin bonded sand and gypsum bonded ceramic space holder particles are used in the open cell foam production. This paper describes the space-holder method for manufacturing open cell aluminum foams and characterizes the density as well as the compressive property of the foams.
Einsatz neuer Werkstoffe für die Weiche — Erfahrungen aus der Sicht des Anwenders*
Authors: Zoll Andreas 
Published: December 2013

Kurzfassung
In den zurückliegenden Jahrzehnten hat die Werkstoff-Beanspruchung durch die Erhöhung der Radsatzlasten und Geschwindigkeiten zugenommen, wodurch die herkömmlichen Werkstoffe für Rad, Schiene und Weichenfahrbahn schneller an die Grenzen ihrer Belastbarkeit gelangten. Dies legte neben der konstruktiven Modifikation des Überlaufbereiches von Weichen auch den Einsatz höherfester Werkstoffe nahe. Für Schienen in Gleis und Weiche sowie für Weichenherzstücke wurden bei der Deutschen Bahn AG in den vergangenen Jahren anhand von Prüfstands- und Gleisversuchen zahlreiche Werkstoffkonzepte für perlitische und bainitische Stähle einer vergleichenden Bewertung unterzogen. Das Ziel bestand darin, die verschieden belasteten Fahrbahnsegmente bei der Entwicklung ihrer symptomatischen Schädigungen zu beeinflussen.
Ablauf einer sicheren Auslegungsberechnung von Getriebegehäusen aus Aluminiumdruckguss*
Authors: Varenkamp Marco , Schön Michael 
Published: December 2013

Kurzfassung
Die Herausforderung bei der Lebensdauerberechnung von Getriebegehäusen aus Aluminiumdruckguss ist zum einen die komplexe Bauteilgeometrie und zum anderen der bedingt durch den Herstellprozess fehlerbehaftete Werkstoff. Die Berechnung erfolgt mittels FEM und Örtlichem Konzept. Das Übertragbarkeitsproblem des Örtlichen Konzeptes wurde durch Abgleiche mit Bauteilversuchen und Optimierung der Übertragungsfunktionen auf Basis statistischer Betrachtungen gemeistert. Die sichere Auslegung wird durch einen Sicherheitsfaktor gewährleistet, der aus der Vertrauenswahrscheinlichkeit der Berechnungsergebnisse hergeleitet wird. Anhand eines Beispiels wird der Ablauf näher erläutert. Darüber hinaus wird gezeigt, dass das Berechnungsergebnis bei mehrstufig einachsiger Belastung durch Verwendung des Schädigungsparameters PJ verbessert werden kann.
General Standard for Welding Simulation*
Authors: Schwenk Christopher , Tikhomirov Dmitrij , Esser Gerd , Rethmeier Michael 
Published: December 2013

Abstract
For differentiating the applicability of various numerical welding simulation methods as well as unifying the prerequisites and the steps to be taken in simulation, normative codes are required for the user. Since any standard-like documents are currently still lacking in this field, the DIN German Institute for Standardization in partnership with the Research Association of DVS German Welding Society have set up a standards committee dealing with the preparation of respective documents.
This article focuses on the presentation of the new DIN Spec 32534-1 explaining the major simulation steps and specifying the application fields and the key terms of welding simulation. In addition, a generally valid simulation structure has been established which is intended to serve as a recommendation for customers and suppliers in formulating and handling a service order as well as for persons who start doing welding simulation for the first time. It additionally gives an overview of the other subject areas dealt with in the standards committee as well as of the international activities in this field.
DIN EN ISO 6892-1:2009 Der Zugversuch — Erste Erfahrungen aus der praktischen Umsetzung der neuen Norm*
Authors: Aegerter Johannes , Kühn Hans-Joachim , Frenz Holger , Weißmüller Christian 
Published: December 2013

Kurzfassung
Mit der Veröffentlichung der DIN EN ISO 6892-1:2009 [1] wurde für den Zugversuch bei Raumtemperatur eine Harmonisierung der in Europa verbindlichen EN 10002-1:2001 [2] mit der ISO 6892:1998 [3] erreicht. Wesentliche Änderungen sind die Einführung der Dehngeschwindigkeit und der Dehngeschwindigkeitsregelung als maßgebliche Prüfgeschwindigkeit bzw. Regelungsart, als Verfahren A bezeichnet. Mit der korrekten Anwendung dieses Verfahrens wird gewährleistet, dass im Moment der Kennwerteermittlung bei enger spezifizierten zulässigen Dehngeschwindigkeitsbereichen vergleichbare resultierende Dehngeschwindigkeiten an der Probe auch bei unterschiedlichen Steifigkeiten der Prüfaufbauten vorliegen. Dieses führt besonders bei dehngeschwindigkeitssensitiven Werkstoffen zu deutlich vergleichbareren Ergebnissen. In diesem Beitrag wird auf die Notwendigkeit der Einführung des Verfahrens A, der möglichen Umsetzungen auch bei Verwendung von älteren Prüfsystemen sowie exemplarisch auf vergleichende Ergebnisse der Verfahren an einem dehngeschwindigkeitssensitivem Stahlwerkstoff eingegangen.
Ausgewählte Schadensfälle aus dem Großgasturbinenbau – Werden wir aus Schaden wirklich klug?*
Authors: Neidel Andreas , Völker Jörg 
Published: December 2013

Kurzfassung
Nach einer kurzen Beschreibung der gasturbinentypischen Leistungsmerkmale und der sich daraus ergebenden spezifischen Bauteilbeanspruchungen zeigt der Beitrag anhand einiger Fallstudien konstruktions-, fertigungs-, montage- und betriebsbedingte Komponentenschäden, die an großen Industriegasturbinen im Laufe ihrer Lebensdauer „von der Wiege bis zur Bahre“, d. h. vom „Reißbrett“ bis zur Revision im Kraftwerk, auftreten können. Folgt man der Terminologie in der angelsächsischen Literatur, die neuerdings zwischen werkstofftechnischem Schadensmechanismus (Physical oder Metallurgical Cause of Failure, z. B. Schwingungsrisskorrosion), Primärursache (Primary Cause of Failure, z. B. zu festes Anziehen einer Rohrverschraubung bei der Montage), Systemursache (Root Cause of Failure, z. B. Verwendung eines falschen Dichtungsmaterials) und organisatorischer Ursache (Organizational Cause of Failure, z. B. fehlende Schulung des Personals) unterscheidet, so beziehen sich die Laboruntersuchungen der Autoren ausschließlich auf erstere Kategorie, wobei die anderen drei zumindest mit erwähnt werden. Vornehmstes Ziel jeder Schadensanalyse ist die Vermeidung von Wiederholfällen, also eines erneuten Schadenseintritts an gleichen Bauteilen unter denselben Bedingungen wie beim Erstschaden. Um „aus Schaden klug zu werden“ sei die Fachgemeinde ausdrücklich ermutigt, in geeigneter Weise noch mehr als bisher über eigene Schadensuntersuchungen zu berichten. Restriktionen und Veröffentlichungsverbote, denen der Schadensanalytiker mitunter begegnet, laufen diesem Ziel zuwider.
Effects of Welding Parameters on the Mechanical Properties of Inert Gas Welded 6063 Aluminum Alloys
Authors: Ertan Taner , Ertan Rukiye , Uguz Agah 
Published: December 2013

Abstract
The influence of welding parameters, namely welding current and gas flow rate, on the mechanical properties of Gas Tungsten Arc Welding (GTAW) and Shielded Metal Arc Welding (SMAW) welded 6063 Aluminum alloy (AA 6063) has been investigated. In order to study the effect of the welding current and gas flow rate, microstructural examination, hardness measurements and room temperature tensile tests have been carried out. The experimental results show that the mechanical properties of GTAW welded joints have better mechanical properties than those of SMAW welded joints. Increasing the welding current appeared to have a beneficial effect on the mechanical properties. However, either increasing or decreasing the gas flow rate resulted in a decrease of hardness and tensile strength. It was also found that, the highest strength was obtained in GTAW welded samples at 220 A and 15 l/min gas flow rate.
Optimisation of GTAW Parameters for the Tensile Strength of AISI 304 Stainless Steel Welds Using the Taguchi Method
Authors: Ertan Rukiye 
Published: December 2013

Abstract
The influence of welding parameters, i. e. the welding current, root gap and the shielding gas flow rate, on the tensile strength of AISI 304 austenitic stainless steel welded with gas tungsten arc welding was investigated. To determine the optimum levels of the parameters, the Taguchi approach was used to increase the tensile strength. The results were analysed by investigating the variance by which welding parameters significantly affect the response. Mathematical models were developed to describe the influence of the selected parameters on the tensile strength. The results were confirmed by experiments.
Microstructural Studies on New Developed Niobium Cast High Speed Tool Steel
Authors: Yilmaz Alpay 
Published: December 2013

Abstract
High speed tool steels, widely used for tools, are characterized of excellent hardness, wear resistance, and high temperature properties. These steels are used not only for metal cutting but also in wood, textile, and leather industries. As in cast and wrought materials, high speed tool steels show a broader application range compared to tool materials which are produced by powder metallurgy. However, the production from bulk material requires high machining costs in the case of specially formed tools. Here is discussed that a new alloying design with niobium differing from known high speed steel chemical alloying designs is created and the production of high speed tool steels in as cast condition without hot working. The microstructure is modified by adding niobium and applying proper heat treatment to get blocky type small monocarbides ending up with providing high toughness and preventing the eutectic carbides which are situated in the interdendritic areas and which increase brittleness between dendrites in the as-cast structure.
Microstructural and Mechanical Properties of Pure Aluminum, 5083 and 7075 Alloys Joined by Friction Stir Welding
Authors: Yilmaz Selim Sarper 
Published: December 2013

Abstract
In this study, microstructural and mechanical properties of pure aluminum, 5083 and 7075 alloys joined by friction stir welding were investigated. Hardness, tensile, bending and impact tests were applied to the welded samples. In addition, optical and SEM tests were carried out. The effects of welding speed on microstructure and mechanical properties were investigated in these materials. Then, the optimal conditions for friction stir welding were determined for pure aluminum, 5083 and 7075 alloys. The maximum hardness was observed for 7075 while the minimum hardness was observed for pure aluminum.
The Effect of the Retrogression Process on the Wear Behaviour of a 7075 Aluminium Alloy
Authors: Durmus Hülya , Uzun Recep Onur , Şahin Salim , Yüksel Nilay 
Published: December 2013

Abstract
Retrogression and re-aging (RRA) process are applied in an attempt to enhance mechanical properties and corrosion resistance of 7075 aluminium alloys. In this study, retrogression and re-aging process have been applied to a 7075 aluminium alloy at 170°C for 5, 40, 80 min and wear resistance of RRA applied samples have been investigated by ball-on-disc wear test apparatus. Sliding distance has been chosen as 300 meters. Re-aging procedure has been carried out at 125°C for 10, 20 and 30 hours. Minimum wear loss has been obtained by retrogression for 40 min and aging for 30 hours.
Recycling of Aluminium Alloy Scraps by Pressure-Assisted Investment Casting for Aluminium Foam Manufacture
Authors: Asavavisithchai Seksak , Jareankieathbovorn Natthida , Srichaiyaperk Areeya 
Published: December 2013

Abstract
Recycling of ADC12 alloy scraps for fabrication of open-cell aluminium foams has been conducted via pressure infiltration method of replication process. The scrap, up to 50 wt.-%, was melted with pure aluminium billet, followed by infiltration in a replicated mold of polyethylene foam structure. Compared with the pure aluminium foam, the compressive strength and hardness are higher the foams with recycled scraps of. The improvement of mechanical properties is due to the presence of Si hard phase in Al matrix. The strength and hardness of the foams also increase with increasing content of scrap.
Effects of Co as an Alloying Element and Heat Treatment Processes on the Properties of High Speed Steels
Authors: Toptop Guven Orkun , Kisasoz Alptekin , Karaaslan Ahmet 
Published: December 2013

Abstract
In this study, effects of Co as an alloying element and different heat treatments processes on the properties of DIN 1.3243 and 1.3343 were investigated. Austenitising and tempering temperatures are critical parameters for steel hardening. Also, Co has critical effect on mechanical properties of high speed steels. Samples were subjected to two different austenitising temperatures with two tempering temperatures. Effects of process parameters on the mechanical properties and tooling abilities of the specimens were investigated. Specimens were characterized by Rockwell hardness tests and tooling abilities of the specimen were determined by characterizing the number of screws that were fabricated with specimens. According to results of experiments, Co has any effect on the hardness of specimens after the austenitising and tempering processes. Moreover, tool life of the specimens were increased by the higher hardening temperatures, the lower tempering temperatures and the presence of Co as an alloying element, because of the positive effect of Co on the hot hardness and hot strength.
Energy Efficient Multiaxial Resonance Test Systems – New Applications and Testing Methods*
Authors: Henze Sven , Hug Joachim , Zorrmann Helge , Scholz Angelina 
Published: December 2013

Abstract
Modern lightweight design is only feasible exploiting properties of geometry and material. In some applications an uniaxial loading of components is not sufficient and a multiaxial loading of forces or moments becomes necessary. In terms of decreasing development cycles and resultant increasing demands on testing frequencies, multiaxial resonance test systems turn into fast, economically advantageous and energyefficient development tools. Well known problems as interference of actuators were solved by the use of particular decoupling devices. Innovative electronic systems and software applications allow matching or different frequencies for each load directions with variable amplitude ratios. Moreover, the phase between the different loading directions is freely adjustable. This development yielded the two-axial crankshaft test, the multiaxial bearing test system, the four point rotating bending rig with superimposed torsion and the multiaxial resonance actuator.