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Rectangular Cross Section (rectangular + cross_section)
Selected AbstractsEin Bemessungsansatz für zweiachsig durch Querkräfte beanspruchte Stahlbetonbalken mit RechteckquerschnittBETON- UND STAHLBETONBAU, Issue 5 2005Peter Mark Dr.-Ing. Für Stahlbetonbalken mit Rechteckquerschnitt und üblichen zweischnittigen Bügeln wird ein Ansatz zur Bemessung gegen geneigt zu den Hauptachsen einwirkende Querkräfte abgeleitet und an Simulationsrechnungen und Experimenten verifiziert. Der Ansatz basiert auf dem der DIN 1045-1 zugrunde liegenden "Fachwerkmodell mit Rißreibung" und ergänzt zur Berücksichtigung einer Querkraftneigung die Gleichungen der Querkraftwiderstände nach DIN 1045-1 durch einfache Faktoren aus Geometrie- und Lastgrößen. Ein Beispiel zeigt, daß die Widerstände merklich abnehmen bzw. höhere Bügelbewehrungsmengen erforderlich sind, falls die Querkraft von einer hauptachsenparallelen Wirkungsrichtung abweicht. Design of Reinforced Concrete Beams with rectangular Cross Sections against biaxial Shear Forces An approach is presented to design reinforced concrete beams with rectangular cross sections and usual stirrups against shear forces that act inclined to the principal axes of the cross sections. It basis on the "truss model with crack friction" and adds supplementary terms to the equations of the shear resistances acc. to DIN 1045-1 to take account for shear force inclinations. Verifications to experimental as well as numerical data are given. An example shows that resistances evidently decrease , or higher amounts of stirrup reinforcement become necessary ,, if shear forces deviate from principal axes. [source] Numerical investigation on J -integral testing of heterogeneous fracture toughness testing specimens: Part I , weld metal cracksFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 8 2003Y.-J. KIM ABSTRACT Based on extensive two-dimensional (2D) finite element (FE) analyses, the present work provides the plastic , factor solutions for fracture toughness J -integral testing of heterogeneous specimens with weldments. Solutions cover practically interesting ranges of strength mismatch and relative weld width, and are given for three typical geometries for toughness testing: a middle cracked tension (M(T)) specimen, single edge cracked bend (SE(B)) specimen and (C(T)) specimen. For mismatched M(T) specimens, both plane strain and plane stress conditions are considered, whereas for SE(B) and C(T) specimens, only the plane strain condition is considered. For all cases, only deep cracks are considered, and an idealized butt weld configuration is considered, where the weld metal strip has a rectangular cross section. Based on the present solutions for the strength mismatch effect on plastic , factors, a window is provided, within which the homogeneous J estimation procedure can be used for weldment toughness testing. The effect of the weld groove configuration on the plastic , factor is briefly discussed, concluding the need for further systematic analysis to provide guidance to practical toughness testing. [source] Bifurcation and stability analysis of laminar flow in curved ductsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2010Werner Machane Abstract The development of viscous flow in a curved duct under variation of the axial pressure gradient q is studied. We confine ourselves to two-dimensional solutions of the Dean problem. Bifurcation diagrams are calculated for rectangular and elliptic cross sections of the duct. We detect a new branch of asymmetric solutions for the case of a rectangular cross section. Furthermore we compute paths of quadratic turning points and symmetry breaking bifurcation points under variation of the aspect ratio , (,=0.8,1.5). The computed diagrams extend the results presented by other authors. We succeed in finding two origins of the Hopf bifurcation. Making use of the Cayley transformation, we determine the stability of stationary laminar solutions in the case of a quadratic cross section. All the calculations were performed on a parallel computer with 32×32 processors. Copyright © 2009 John Wiley & Sons, Ltd. [source] Dynamic Compressive Failure of AlON Under Controlled Planar ConfinementJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2008Bhasker Paliwal An experimental technique is developed to impose a planar lateral confinement in a prismatic specimen (with a rectangular cross section); the setup enabled a controlled and homogeneous stress state with high lateral compressive stresses. A transparent polycrystalline aluminum oxynitride (AlON) specimen was used for the study. The statically precompressed specimen was then subjected to axial dynamic compressive loading using a modified compression Kolsky bar setup. Experimental design was performed using 3D computational modeling. Initial exploratory experiments were conducted on AlON at an average planar confinement of 400,410 MPa; the results suggested a higher compressive strength and a nonlinear stress evolution in AlON due to the confinement. A high-speed camera was used to observe the damage evolution in the specimen during the course of loading. The photographs and stress evolution are suggestive of an additional inelastic deformation mechanism, whose evolution is slower than the typical brittle-cracking type of damage apparent in the unconfined case. The TEM and high-resolution electron microscope analysis indicated dislocation plasticity in some fragments; dislocations in the slip bands were characterized to be dissociated ,110, dislocations on {111} planes. The width between two partial dislocations was about 15 nm, suggesting low stacking fault energy of AlON. Microscopic characterization also shows that the eventual fragmentation of AlON is by cleavage mainly along low-index {111} planes. [source] Nachweis der Gebrauchstauglichkeit von Bauteilen aus Stahlbeton nach DIN 1045 und nach EC 2BAUTECHNIK, Issue 10 2007Richard Friedrich Dr.-Ing. Der Beitrag behandelt die häufig vorkommenden biegebeanspruchten Bauteile mit rechteckförmigem Querschnitt aus normalfestem Normalbeton C 20 bis C 50 mit einseitiger Bewehrung aus Betonstahl BSt 500. Bei der Berechnung der Durchbiegung w wird das Betonkriechen und -schwinden berücksichtigt, bei der Berechnung der Rißbreite wk und der Spannungen ,c und ,s das Kriechen allein. Design of reinforced concrete members for serviceability after DIN 1045 and after EC 2. Considered are the frequently used members with rectangular cross section in normal strength normal concrete C 20 up to C 50 and one-sided reinforcement with steel BSt 500. For the calculation of the deflection w, both concrete creep and shrinkage are taken into consideration, for the calculation of the crack width wk and the stresses ,c and ,s the creep only. [source] Ein Bemessungsansatz für zweiachsig durch Querkräfte beanspruchte Stahlbetonbalken mit RechteckquerschnittBETON- UND STAHLBETONBAU, Issue 5 2005Peter Mark Dr.-Ing. Für Stahlbetonbalken mit Rechteckquerschnitt und üblichen zweischnittigen Bügeln wird ein Ansatz zur Bemessung gegen geneigt zu den Hauptachsen einwirkende Querkräfte abgeleitet und an Simulationsrechnungen und Experimenten verifiziert. Der Ansatz basiert auf dem der DIN 1045-1 zugrunde liegenden "Fachwerkmodell mit Rißreibung" und ergänzt zur Berücksichtigung einer Querkraftneigung die Gleichungen der Querkraftwiderstände nach DIN 1045-1 durch einfache Faktoren aus Geometrie- und Lastgrößen. Ein Beispiel zeigt, daß die Widerstände merklich abnehmen bzw. höhere Bügelbewehrungsmengen erforderlich sind, falls die Querkraft von einer hauptachsenparallelen Wirkungsrichtung abweicht. Design of Reinforced Concrete Beams with rectangular Cross Sections against biaxial Shear Forces An approach is presented to design reinforced concrete beams with rectangular cross sections and usual stirrups against shear forces that act inclined to the principal axes of the cross sections. It basis on the "truss model with crack friction" and adds supplementary terms to the equations of the shear resistances acc. to DIN 1045-1 to take account for shear force inclinations. Verifications to experimental as well as numerical data are given. An example shows that resistances evidently decrease , or higher amounts of stirrup reinforcement become necessary ,, if shear forces deviate from principal axes. [source] | |||||||||||||