bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of Automotive Composite Bumper Beams and Hood Subjected to Frontal Impacts
Authors: Jalauddin Mai Nursherida , Ali Aidy , Sahari Barkawi , Aziz Nuraini Abdul 
Published: December 2013

Abstract
Performance of automotive composite bumper beam subjected to frontal impact is presented and discussed in this paper. The aim of this study is to analyze the effect of steel and composite materials on internal energy of the automotive front bumper beam and with respect to pedestrian head injury at the hood. The front bumper beams and hood made of aluminum AA5182, e-glass/epoxy composite and carbon epoxy composite were studied and characterized by impact modeling using LS-DYNA V971, according to United States New Car Assessment Program (US-NCAP) defining the frontal impact velocity and based on European Enhanced Vehicle-Safety Committee. The most important variables of this structure were mass, material, internal energy, and the so-called Head Injury Criterion (HIC). The results are compared with a bumper beam and a hood made of mild steel. The in-plane failure behaviors of the composites were evaluated by using the Tsai Wu failure criterion. LS-DYNA Finite Element Analysis software was used. The results showed that a carbon fiber/epoxy composite bumper can reduce the bumper mass and has the highest value of internal energy followed by the glass fiber/epoxy composite. The FE model of a production hood was introduced and validated. In order to evaluate the protective performance of the baseline hood, the FE models for a 50 percentile of an adult pedestrian dummy were used to impact the hood. It was found that the aluminum AA5182 hood can obviously reduce the Head Injury Criterion (HIC) values compared to the baseline hood. The HIC values of the dummy model were further reduced to much lower than 1000.
Effects of Squeeze Pressure on Microstructure, Porosity and Hardness of an In-Situ Mg2Si/Al–Si–Cu Composite
Authors: Ozer Gökhan , Güler Kerem Altug , Lus Hüseyin Murat 
Published: December 2013

Abstract
The effect of applied pressure on microstructures and properties of an in-situ formed Mg2Si/Al-Si-Cu reinforced metal matrix composite fabricated by squeeze casting are investigated. Due to the wide solidification range and the high viscosity, this type of composites is prone ro shrinkage and gas porosity. In order to improve cast ability and to obtain better properties, the squeeze casting technique has been used. The results showed that primary Mg2Si crystals are formed by adding pure Mg into the hypereutectic Al-Si-Cu alloy (A380). It was found that, with the application of 30 MPa and 40 MPa pressure during solidification, the average size of primary Mg2Si particulates decreases from about 87 µm to about 21 and 18 µm and that the average porosity values of the cast samples is significantly decreased from 8.75 % to 0.50 and 0.35 %, respectively.
Determination of Mechanical Properties and Failure Pressure in Composite Cylinders
Authors: Benli Semih , Özen Mustafa , Sayman Onur , Deniz Mehmet Emin 
Published: December 2013

Abstract
In this study, mechanical properties of cylindrical composite specimens were measured experimentally. Composite cylinders oriented at 0° C and 90° were manufactured by using the hand lay -up technique. The cylinders were loaded axially for measuring the axial tensile strength and compressive strengths. Some specimens were attached to a torsion machine for measuring shear strength and shear modulus. Thus, a close and true measuring was performed in the cylindrical specimens. A finite element solution was performed in closed ended composite cylinders under internal pressure and thermal loading. Thermal stresses occur at low and high temperatures with respect to the room temperature. For a true or close solution in composite cylinders, mechanical properties should be determined in cylindrical composite specimens.
Effect of Nanocomposite Coating with Different Concentrations on the Fatigue Life of Stainless Steel316 with Different Surface Roughness
Authors: Hedia Hassan S. , Aldousari Saad. M. , Abdellatif Ahmed K. , Gadhi Raed Hasan M. 
Published: December 2013

Abstract
Many experimental researches succeeded to improve fatigue properties of materials by treating their surfaces. In this study, the benefits of nanocomposite material are used to investigate the fatigue life of stainless steel specimens with different surface roughness. Nanocomposite coating was prepared with different concentrations (0.3 %, 0.5 %, and 0.7 %) of multi wall carbon nano tubes MWCNT. This coating was applied on stainless steel test specimens with four different values of the surface roughness (0.3, 0.8, 1.6, and 2.5). It turned out that fatigue life increased more than four times compared to the original material when using 0.5 % and 0.7 % MWCNT concentration in coating composition with the 0.3 surface roughness, while no significant difference was detected at another roughness.
Erosion Process of 66 MW Steam Turbine Rotor Blades
Authors: Staniša Branko , Schauperl Zdravko , Šnajdar Mateja 
Published: December 2013

Abstract
Apart from erosion of leading edges, erosion of the rotor blades trailing edges often occurs in condensing steam turbines, due to the impact of wet steam water droplets. Considerable erosion of the rotor blades trailing edges may be more dangerous for a reliable turbine operation than the leading edges erosion. During several years of research many results concerning erosion damage to the trailing edges of 66 MW condensing reduction steam turbine final stage rotor blades at the Thermo-electric power plant – heating plant (TE-TO) Zagreb have been gathered and are presented in this paper. Correlation between the erosion process behavior of the last stage turbine rotor blades trailing edges and the number of operating hours has been established.
Impact Resistance of Armor Composite Made of Kevlar29 and Al2O3 Powder
Authors: Ali Aidy , Abbud Luay Hassim , Talib A. R. Abu , Mustapha Faizal 
Published: December 2013

Abstract
In this study, the impact behavior of a composite material made from Kevlar29 – Al2O3/ epoxy for hard body armor is considered. The present experimental method focused on the behavior of the ballistic limit, energy absorption, and final velocity of flat cylindrical and conical projectiles. The results indicated that the maximum ballistic limit at impact velocity is 400 ±7 m/s for an 18 mm target thickness. Experimental results showed that the best ballistic performance was achieved with composite materials made of Kevlar29 – Al2O3/epoxy. The results concerning the initial and final velocities showed good agreement compared with the Ipson and Recht equation.
Neuartige automatisierte Stangenprüfung mit Ultraschall-Gruppenstrahlern
Authors: Schenk Gottfried , Brackrock Daniel , Dohse Elmar , Ploigt Roy , Deutsch Wolfram 
Published: December 2013

Kurzfassung
Wie erkennt man Risse oder Einschlüsse in Stabstahl, bevor daraus beispielsweise eine Automobil-Antriebswelle entsteht? Halbzeug­produkte werden vor der Weiterverarbeitung zerstörungsfrei auf Fehlerfreiheit geprüft, denn nicht erkannte Schäden können teure Rückrufaktionen zur Folge haben. Dieser Beitrag stellt ein Verfahren vor, mit dem die bisherige konventionelle Ultraschallprüfung durch die Gruppenstrahlertechnik ersetzt wird und die Prüfqualität bei gleichzeitiger Beschleunigung des Prüfvorgangs signifikant erhöht werden kann.
Structural Design Optimization of Vehicle Components Using Cuckoo Search Algorithm
Authors: Durgun İsmail , Yildiz Ali R. 
Published: December 2013

Abstract
In order to meet today's vehicle design requirements and to improve the cost and fuel efficiency, there is an increasing interest to design light-weight and cost-effective vehicle components. In this research, a new optimization algorithm, called the Cuckoo Search Algorithm (CS) algorithm, is introduced for solving structural design optimization problems. This research is the first application of the CS to the shape design optimization problems in the literature. The CS algorithm is applied to the structural design optimization of a vehicle component to illustrate how the present approach can be applied for solving structural design problems. Results show the ability of the CS to find better optimal structural design.
Regression Based Neural Network Modeling for Forecasting of the Metal Volume Removal Rate in Turning Operations
Authors: Kahraman Funda , Esme Ugur , Kulekci Mustafa Kemal , Kazancoglu Yigit 
Published: December 2013

Abstract
The present paper focuses on two techniques, namely regression and neural network, for predicting tool wear. Predicted values of tool wear by both techniques were compared with experimental values. Also, the effects of the main machining variables on tool wear have been determined. The metal volume removed (MVR) was taken as response (output) variable and cutting speed, feed rate, depth of cut and hardness were taken as input parameters, respectively. The relationship between tool wear and machining parameters was found out by direct measurement of the tool wear by MVR. The results showed the ability of regression and neural network models to predict the tool wear, accurately.
The Bulky Paper Properties Influence on the Adhesive Bond Strength
Authors: Preprotić Suzana Pasanec , Budimir Ivan , Lajić Branka 
Published: December 2013

Abstract
Adhesive bond strength depends on adherend, adhesive and interphase zone. Adhesive joint includes bonded areas or binding edges across bonded layer. Research of adhesive bond strength focuses on understanding the properties of bulky paper associated with formation of the interphase and adhesive joint failure mode. The key contributors of good adhesive bond strength are paper rough surface necessary for mechanical interlocking, adequate adhesive flow and adaptationfor intimate interaction and acceptable adhesive setting time. Change of parameters has strong influence on final adhesive joint formation. Adhesive bond strength assessment involves adhesive joint strength determination. Pull test method is used for adhesive joint failure mode characterization. Furthermore, adhesive joint strength results directly explain bulky paper bind ability by perfect binding technique. FOGRA recommendation rating directly confirms paperback binding quality with bulky paper application. Understanding of bulky paper bind ability involves comprehensive physiochemical knowledge of material (paper, adhesive). In addition, this binding technique is more unique because of its interest for adhesive joint formation.
Effect of Nanoclay Amount and Compatibilizer Presence on Thermal, Morphological and Mechanical Behaviour of Nanoclay Reinforced Composite Polypropylene Cast Film
Authors: Gocek Ikilem , Adanur Sabit 
Published: December 2013

Abstract
Pure PP film without compatibilizer and nanoclay, nanoclay reinforced PP film without compatibilizer and nanoclay reinforced PP films with compatibilizer were produced to study the effect of nanoclay amount and compatibilizer presence on thermal, morphological and mechanical properties of films. Reinforced films were produced with 1% and 3% nanoclay contents with 3 different compatibilizer amounts to examine if nanoclay addition changes properties of the films in the same manner with different compatibilizer amounts. Melting points of the films slightly increase as the nanoclay content increases. Decomposition temperatures increase, as the nanoclay content increases. As the nanoclay content increases, tensile, burst and tear strengths for the reinforced films decrease. It can be observed that the increase in nanoclay content lowers strain and extension values for reinforced films due to nanoclay dispersion.
Characterization of Au-Ga Alloys with Low Gold Content
Authors: Gomidželović Lidija , Živković Dragana , Talijan Nadežda , Ćosović Vladan , Balanović Ljubiša 
Published: December 2013

Abstract
The results of an experimental investigation of structural, mechanical and electrical characteristics of the alloys in Au-Ga system are presented in this paper. Selected alloys AuxGay (x = 0.1 — 0.3) were examined using light microscopy and SEM-EDX analysis as well as hardness, microhardness and electroconductivity measurements.
Determination of the Minimal Operating Temperature
Authors: Levi Avram 
Published: December 2013

Abstract
According to a new theory poycrystal elements are a comlex self-organized system which gives the possibility to modulate the processes of strengthening by changing temperature within a wide range. An unconventional method for non-destructive determination of the minimal operating temperature (ductile to brittle transition temperature of structural steel TDBTT), based on the results of measuring the speeds of longitudinal and transversal ultrasonic waves and the achieved values of Poisson's ratio, has been developed.
Effect of Heat Treatment Conditions on Microstructure and Mechanical Properties of Long Term Serviced Fe25Cr-35Ni Alloy
Authors: Hemmatad Kannika , Visuttipitukul Patama , Wangyao Panyawat , Lothongkum Gobboon 
Published: December 2013

Abstract
HP alloy Fe-25Cr-35Ni is widely used in petrochemical industry, because of its good corrosion and oxidation resistance at high temperature. As-cast microstructure of HP alloy consists of eutectic carbide in discontinuous network. After service in carburizing atmosphere at high temperature, the microstructure of serviced HP alloy, which consisted of carbide network that was thicker and coarser than as-cast specimens as well as irregular shape carbide, lost its tensile strength and fracture elongation properties. However, the hardness increased. The serviced HP alloys were heat treated in 12 conditions, which could be classified in four main categories. The first one was solutionized at three different temperatures — 1,373, 1,423 and 1,473 K. The second was solutionized at 1,373 K and aged at 1,073, 1,173 and 1,273 K. The third was solutionized at 1,423 K and aged at 1,073, 1,173 and 1,273 K. The last one was solutionized at 1,473 K and aged at 1,073, 1,173 and 1,273 K. The process time for solution was 21.6 ks and aging is 86.4 ks for all conditions. The result showed that the amount of Cr rich carbide vastly decreased after heat treatment in all conditions. The Vicker hardness values (HV) of all heat treated specimen decreased comparing to that of serviced alloy. In conclusion, heat treatment provided new microstructures with lower amount of carbide networks of serviced alloy which resulted in improvement of tensile strength and fracture elongation properties.
Determination of Elastic Plastic Fracture Toughness Parameters for a Compact Tension Specimen Using the Finite Element Method
Authors: Özdemir Uğur , Yeni Çinar 
Published: December 2013

Abstract
In this study, elastic-plastic fracture toughness of an aluminum alloy is investigated. J-integral was calculated using the finite element software and formulation. Crack tip opening displacement (CTOD) is determined by using the plastic hinge model (δph) and direct measurement (δ5). J-Δ a and CTOD-Δ a resistance curves are constructed and compared with those obtained from formulation and those generated from test data, respectively. Good agreement has been obtained between the test results, the formulation and the results of the finite element analysis. The relationship between δph and δ5 is nonlinear and as CTOD increases δ5 becomes larger than δph. The relationship between J-integral and CTOD is found to be linear for both δph and δ5. It has been seen that the proportionality constant dn considerably depends on the method of calculation of CTOD.
Structural Damage Detection Using Modal Parameters and Particle Swarm Optimization
Authors: Gökdağ Hakan , Yildiz Ali R. 
Published: December 2013

Abstract
Vibration based on structural damage detection (DD) is an important subject in many fields of engineering. Detection of possible damage locations before destructive stiffness losses in the engineering structures occur, is a main goal of DD. This paper describes the damage detection in structural elements by means of Particle Swarm Optimization algorithm (PSO). In this regard, the finite element model of a Timoshenko beam is considered, and damage is assumed as a stiffness loss in some elements. Damage locations and extents are identified minimizing some well-known modal parameter based objective functions. It is concluded that modal flexibility is the best among the considered damage indexes. Also, the results show that PSO is an effective optimization approach in structural damage detection.
Examination of Microstructure and Wear Behaviour of a Roller Material Produced by Centrifugal Casting
Authors: Birbaşar Onur , Atapek Ş. Hakan , Türedi Enbiya , Zeren Muzaffer 
Published: December 2013

Abstract
In this study, the microstructure of a roller material produced by centrifugal casting was characterized and its worn surface was examined after wear test. In the first stage of the study, centrifugal casting was used to produce cast iron based roller material. The cross-section of cast matrix was examined using light and scanning electron microscopy after metallographic preparations. In the second stage, ‘ball-on-disc’ type tribometer was used to investigate the wear behaviour of the cast part under dry sliding condition. In order to observe the effect of loading force, the samples were subjected to 10 N, 30 N and 50 N load and the total sliding distance was selected as 500 m. After wear tests, all the worn surfaces were examined using both light and scanning electron microscopy. It is concluded that (i) the roller had pearlitic cast iron matrix having nodular graphite and eutectic carbide, (ii) worn surfaces exhibited typical abrasive and partial adhesive wear tracks, (iii) as the loading force increased the friction coefficient in addition to weight loss of cast iron matrix increased.
Application of Genetic Algorithm (GA) for Optimum Design of Module, Shaft Diameter and Bearing for Bevel Gearbox
Authors: Mendi Faruk , Baskal Tamer , Külekci Mustafa Kemal 
Published: December 2013

Abstract
In this study selection of optimum module, shaft diameter and rolling bearing for conical gear has been done using genetic algorithm (GA). GA, is a novel stochastic method of optimization. GAs are based on the principles of natural selection and evolutionary theory. Objective function was optimized for the design variables between determined boundary values. The GA was constrained by taking into account the power, moment, velocity, wall thickness and bearing distances. Tooth strength and surface crush were considered to be design constraints for module optimization. The other algorithm constraints are maximum bending and torsion moments for shaft optimization, and working life for bearing optimization.
Experimentelle und rechnerische Qualifikation der Vibrationsfestigkeit von elektrotechnischen Großbaugruppen im Lastfall Erdbeben*
Authors: Rödling Steffen , Brettner Bernd 
Published: December 2013

Kurzfassung
Einrichtungen zur Übertragung und Erzeugung von elektrischer Energie werden in allen Regionen der Welt errichtet. Auch in solchen, in denen Erdbeben nicht ausgeschlossen werden können oder sogar erwartet werden müssen. Um die Sicherheit der Anlagen zu gewährleisten, ist hier der Nachweis der Standfestigkeit, Integrität und Funktion der Geräte und Komponenten unter erdbebenspezifischen Belastungen erforderlich. Der in der vorliegenden Veröffentlichung beschriebene experimentelle Nachweis an einem Laststufenschalter für Transformatoren wurde bei der IABG mbH, Ottobrunn, durch rechnerische Methoden begleitet und ergänzt. Auf diese Weise wurde ein mit statischen und dynamischen Versuchen abgeglichenes Rechenmodell erstellt, welches bei zukünftigen Qualifizierungen veränderter Baustände herangezogen werden kann. Durch Model-Update werden die so verifizierten Modelle und Methoden angepasst und zur Qualifikation veränderter Typen verwendet.
Optimierter Lebensdauer-Berechnungsprozess von Eisengussbauteilen unter Berücksich-tigung des lokalen Gefüges*
Authors: Hack Michael , Jung Dominik , Egner-Walter Achim 
Published: December 2013

Kurzfassung
Der Herstellungsprozess hat in vielen Fällen einen großen Einfluss auf die Betriebsfestigkeit von Bauteilen. Wird dieser vernachlässigt, führt dies im Allgemeinen zu unnötig konservativer Bauteilauslegung und hohen Bauteilgewichten. So wird in der Betriebsfestigkeitsberechnung für Gusseisenkomponenten heute – mangels quantitativer Informationen – meist von homogenen Materialeigenschaften ausgegangen. In diesem Beitrag wird ein durchgehender Berechnungsprozess entlang der Programmpakete Magmasoft – Abaqus – Virtual. Lab Durability vorgestellt, der die erstarrungsbedingt örtlich variierenden Gefügeeigenschaften im Bauteil berücksichtigt. Der Prozess wird exemplarisch an einem Sphäroguss-Bauteil demonstriert.
Surface Properties and Fatigue Life of Stress Peened Leaves
Authors: Savaidis Alexander 
Published: December 2013

Abstract
Experimental results referring to the influence of stress peening treatment on the metallurgical, surface and mechanical properties, especially the fatigue life of parabolic leaf springs made of two high-strength steels, 52CrMoV4 and 51CrV4, are presented. The tested leaves were manufactured under serial conditions. The microstructure, surface roughness, hardness and residual stress profiles as well as Wöhler curves are determined and assessed both in a qualitative and quantitative manner. Compressive residual stresses, increased hardness values and pronounced roughness are determined on the specimens’ stress-peened surface. The experimentally determined Wöhler curves explore the mutual influence of material, surface properties and surface roughness on fatigue behaviour and lifetime. Equivalencies of both raw materials refered to the mechanical properties achieved after the heat treatment and stress peening process are observed.
Bewertung mikrostruktureller Barrieren während der Ermüdungsschädigung von Duplexstählen bei sehr hohen Zyklenzahlen*
Authors: Krupp Ulrich , Giertler Alexander , Marinelli Maria Cecilia , Dönges Benjamin , Knobbe Helge , Christ Hans-Jürgen 
Published: December 2013

Kurzfassung
Wechselverformungsexperimente unter Anwendung verschiedener Prüftechniken, wie Servohydraulik, Resonanzprüfmaschinen, Umlaufbiegung und Ultraschall, sowie eine systematische mikrostrukturelle Auswertung der Oberfläche nach vorgegebenen Lastwechselintervallen mithilfe der analytischen Rasterelektronenmikroskopie weisen darauf hin, dass Korn- und Phasengrenzen maßgeblich das Ermüdungsverhalten von Duplexstählen beeinflussen. Je nach räumlicher Orientierung der Gleitsysteme benachbarter Körner und Phasenbestandteile kann die lokale Bildung von Scherbändern erklärt werden, die auch über Grenzflächen hinaus wachsen und schließlich zu Rissinitiierung, Ermüdungsrissausbreitung und Bruch führen.
Einflüsse der Mikrostruktur auf die Ermüdungsschädigung der Aluminiumlegierung EN AC-Al Si7Mg0,3*
Authors: Giertler Alexander , Siegfanz Stephanie , Libally Thomas , Michels Wilhelm , Krupp Ulrich 
Published: December 2013

Kurzfassung
In dieser Arbeit sind erste Ergebnisse einer Untersuchung des Einflusses der Mikrostruktur auf die Ermüdungsschädigung der Aluminiumgusslegierung EN AC-Al Si7Mg0,3 zusammengestellt. Hierzu erfolgte zunächst die Herstellung korngefeinter und veredelter Probestäbe durch Abgießen in eine Stahlkokille. Mit gezielten Wärmebehandlungen konnte die Festigkeit des α-Mischkristalls, bei gleicher Größe und Form der eutektischen Phase variiert werden. In den anschließenden Ermüdungsversuchen konnte bei Proben, die bei einer höheren Lösungsglühtemperatur geglüht wurden, eine gesteigerte Lebensdauer festgestellt werden.