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Load Carrying Capacity (load + carrying_capacity)
Selected AbstractsFracture analysis of strength undermatched Al-Alloy welds in edge cracked tensile panels using FITNET procedureFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 9 2008S. CICERO ABSTRACT This paper presents a methodology for the assessment of the remaining load carrying capacity of thin-walled components under tension containing highly strength undermatched welds and edge cracks. The analysis is based on the strength mismatch option of the fracture module, part of the newly developed European fitness-for-service (FFS) procedure FITNET. The mismatch option of the FITNET fracture module allows weld features such as weld tensile properties and weld geometry to be taken into account in the fracture analysis of cracked welded components. The methodology described was verified for centre cracked Al-alloy large tensile panels containing undermatched welds in Ref. [1] and hence the present work provides validation with experimental results of the single edge cracked (SEC) and double edge cracked (DEC) panels. The material used is an age-hardening aluminium alloy 6013 in T6 temper condition used in welded airframe components. The welds in the form of butt joints were produced using the CO2 laser beam welding process. The results show that by using the FITNET FFS methodology with an appropriate selection of the input parameters, safe acceptable predictions of the maximum load carrying capacity of the welded panels can be obtained. It should also be noted that one of the main difficulties that engineers encounter when applying mismatch analysis for first time is its apparent complexity. A step-by-step analysis is proposed here in order to provide guidance for this kind of assessments. [source] Capacity of selected ionic liquids as alternative EP/AW additiveLUBRICATION SCIENCE, Issue 6-7 2010Ameneh Schneider Abstract In this paper, it is shown that specific ionic liquids have great potential to be used as additives for tribological applications. The results promise a high load carrying capacity; especially for the cation 3-Octhylthiazolium and long term stability up to temperatures of 120°C is given. However, only extreme pressures/anti-wear properties are examined in detail with the selected test method. Friction modifier (FM) effectiveness cannot easily be demonstrated, because of the good performance of the selected base stock. Nevertheless, ionic liquids in general did not change the FM characteristic of the base oil in a negative way. A promising potential for ionic liquids to replace a majority of additives in tribological systems is given. Methods used are Schwing-Reib-Verschleiß test according to DIN ASTM D 5706, and Four Ball Tests according to DIN 51360. Mechanisms related to additives in lubricants are investigated by X-ray photoelectron spectroscopy. Copyright © 2010 John Wiley & Sons, Ltd. [source] Surface roughness effects on thermo-hydrodynamic lubrication of journal bearings lubricated with bubbly oilLUBRICATION SCIENCE, Issue 1 2006A. M. A. El-Butch In this paper, the combined effect of surface roughness and bubbles content on the hydrodynamic performance of journal bearings is studied. In the analysis, it is assumed that the bearing and shaft surfaces are covered with homogeneous isotropic roughness, the air bubbles are evenly distributed through the lubricant and the bubble size is very small. The modified Reynolds equation governing the pressure generation in the bearing gap for compressible fluid is solved simultaneously with the energy equation. Temperature and pressure distributions, coefficient of friction, bearing load capacity and attitude angle as affected by surface roughness, bubble content and some bearing parameters are presented. Results showed that the bearing load carrying capacity is higher at higher values of average roughness and higher bubble content as a direct consequence of the higher pressure values attained, and the average roughness and the bubbles content had no significant effect on the attitude angle. Copyright © 2006 John Wiley & Sons, Ltd. [source] Repeated impact behavior of glass/epoxy laminatesPOLYMER COMPOSITES, Issue 11 2009Bulent Murat Icten The response of glass,epoxy composites to repeated impact for various impact energies ranging from 5 to 15 J was investigated. Specimens with two different stacking sequences were studied; [0/90/0/90]S and [0/90/+45/,45]S. In addition to the room temperature, impact tests were also performed at ,40°C environmental test temperature for impact energy of 15 J. Contact force-deflection and energy-time curves at each test and the number of impacts to failure (Nf) were obtained for each experiment. Compression after impact (CAI) tests were also conducted to determine the residual load carrying capacity of the damaged specimens. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Low velocity impact response of GFRP laminates subjected to cycling moisturesPOLYMER COMPOSITES, Issue 5 2000Guoqiang Li The low velocity impact response of laminated composites in ambient hygrothermal environments has been extensively investigated. This response, however, is not well understood when subjected to moisture cycling at elevated temperatures. In this current study, two types of glass fiber reinforced plastic (GFRP) laminates, unidirectional and crossply, were conditioned in a conditioning chamber for a maximum of eight moisture cycles at conditioning temperatures from 50°C to 100°C. Low velocity impact tests were conducted on the conditioned specimens and control specimens via an instrumented drop-weight impact testing machine. The tension after impact (TAI) strength was investigated using an MTS machine. The equivalent damage size is obtained using an average stress criterion found in the literature. The effect of moisture cycling and conditioning temperatures on the low velocity impact response and residual load carrying capacity of GFRP laminates are evaluated via the test results. [source] Synthesis and characterization of some novel silicon esters and their application as lubricant base stock solutionAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2009Kanak Saxena Abstract A series of functional organosilanes and their esters were synthesized by the hydrosilylation reaction of SiH group-bearing organosilicon derivatives with maleic anhydride using Speier's catalyst and their esterification with long-chain alcohols in the presence of stannous oxide. These products have been characterized using elemental analysis, FT-IR, 1H, 13C and 29Si NMR. Viscosity, density, pour point, flash point and tribological properties of these compounds have also been evaluated. These esters have a pour point of <,60 °C, a flash point of ,200 °C (closed-cup) and excellent load carrying capacity. Copyright © 2009 John Wiley & Sons, Ltd. [source] Die Tragfähigkeit verleimter Brettschichtholzbinder in Abhängigkeit von der TemperatureinwirkungBAUTECHNIK, Issue 6 2006Horst Falkner Univ.-Prof. Bei einem Bauvorhaben wurde als Tragstruktur für die Glasfassade eine Holzleimstruktur eingesetzt. Da nicht auszuschließen war, daß die Temperatur der Fassadenhölzer unter Sonneneinwirkung eine Größe von 60 °C erreichen konnte, wurde der Einfluß der Temperatur auf die Tragfähigkeit der Leimverbindung untersucht. Hierzu wurden aus dem Bauvorhaben einige Proben entnommen und am iBMB (Institut für Baustoffe, Massivbau und Brandschutz) der TU Braunschweig unter Variation der Bauteiltemperatur nach DIN 52186 geprüft. Dabei ergab sich bis zu einer Temperatur von 30 °C keine Veränderung der Tragfähigkeit. Bei höherer Temperatureinwirkung von 80 °C betrug die Tragfähigkeit nur noch 30% derjenigen unter Normaltemperatur. Hier wurde der Bruch durch ein Versagen der Leimfuge eingeleitet. Load-carrying capacity of glued laminated wood girders under temperature influence. For a building project, a load carrying structure for the glass façade consisting of glued laminated wood was chosen. As it could not be excluded that the temperature of the wood under solar radiation might reach up to 60 °C, the temperature influence on the load carrying capacity of the glued laminated wood had to be investigated. Samples were taken from the wooden structure and tested at the iBMB (Institute for Building Materials, Concrete Construction and Fire Protection) under temperature variation according to DIN 52186. No reduction in the load carrying capacity was observed for temperatures up to 30 °C. For a higher temperature of 80 °C a reduction of the load carrying capacity of 70% was observed. The fracture was induced by the failure of a glued joint. [source] Knotengestaltung hybrider Fachwerkkonstruktionen , Entwicklung neuartiger Tragwerkskonzepte unter Verwendung von Ultrahochleistungsbeton (UHFB)BAUTECHNIK, Issue 5 2006Nguyen Viet Tue Prof. Dr.-Ing. habil. Fachwerkkonstruktionen zählen zu den leistungsfähigsten raumbildenden Strukturen der Baugeschichte. Rein normalkraftbeanspruchte Bauteile zeichnen sich vor allem durch minimalen Werkstoffaufwand aus. Die Einsatzgebiete von Fachwerken sind so vielgestaltig wie deren Ausführungsformen selbst. Gerade in den letzten Jahren gewinnen Fachwerkkonstruktionen z. B. beim Bau transparenter Hochhäuser oder für Stadien und Veranstaltungsarenen und vereinzelt auch wieder im Brückenbau, verstärkt an Bedeutung. Mit finanzieller Unterstützung der Bilfinger | Berger AG wurde an der Universität Leipzig ein stabförmiges Verbundbauteil aus einem stahlummantelten ultrahochfesten Beton entwickelt. Das neue Tragelement kennzeichnet sich durch seine hohe Tragfähigkeit unter Druckbeanspruchung sowie großer Duktilität. Dieser hybride Verbundstab stellt, einschließlich einer innovativen Knotenlösung, eine sinnvolle, wirtschaftliche und vor allem architektonisch ansprechende Alternative zu den herkömmlich konstruierten Fachwerken, dar. In diesem Beitrag wird über die Besonderheiten dieser Konstruktionsform sowie über die Entwicklung geeigneter Knoten berichtet. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Design of joints for hybrid truss structures. Truss constructions belong to the most efficient spatial structures in building history. Purely longitudinal stressed members are characterized by a minimum material expense. The application areas of truss members are as multiform as their embodiment. Recently, truss constructions increase importance due to their application within transparent tall buildings, stages, arenas, bridges etc. With the financial support of Bilfinger | Berger AG, at the University of Leipzig a bar-shaped composite member was developed using a steel-encased Ultra High Performance Concrete (UHPC). This new structural member is distinguished by its high load carrying capacity under compression stress as well as high ductility. Including an innovative joint solution, this hybrid composite bar is a reasonable, economic, and above all, an architectural appealing alternative to a conventionally designed truss structure. In the following contribution, some features of this member and the development of appropriate joints are described. [source] Torsionsversuche an textilbetonverstärkten StahlbetonbauteilenBETON- UND STAHLBETONBAU, Issue 12 2009Frank Schladitz M.Sc. Versuche Abstract Zur Untersuchung des Torsionstragverhaltens von textilbetonverstärkten Stahlbetonbauteilen wurden Torsionsversuche an Bauteilen mit runden und quadratischen Querschnitten durchgeführt. Anhand von Versuchsergebnissen wird gezeigt, dass durch die Textilbetonverstärkung die Tragfähigkeit und Gebrauchstauglichkeit deutlich verbessert werden kann. Die Ergebnisse der experimentellen Untersuchungen werden mit Hilfe von Stabwerksmodellen beschrieben. Torsion Test at Textile Reinforced Concrete Strengthened Components In order to examine the torsion bearing behaviour of textile reinforced concrete components torsion tests have been carried out at building units with round and square shaped cross sections. Test results display that using textile reinforced concrete can considerably improve the load carrying capacity and the serviceability. The results of the experimental research are being described by strut-and-tie models. [source] | |||||||||||||