Influence of Grooved Plate Cross-Sectional Shape on Bending Phenomena in Laser-Quenching Forming Process

This research proposes a method to achieve laser quenching and laser forming simultaneously. This technique uses a diode laser to produce thin steel sheet-assuming parts, such as springs and hinges. Energy and time are saved by combining the advantages of laser quenching, which has high input heat efficiency, and laser forming, which, unlike press molding, does not require metal molds. In this study, laser-quenching molding was performed for an entire thin steel plate, and the influence on warping was investigated. Furthermore, the proposed method was evaluated under repeated quenchings for different cross-sections of a workpiece. The results indicated that the technique prevented bending deformation during the next laser scan and reduced warping by increasing the second moment of area of the entire workpiece.

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Automated 3D measurement of fiber cross section morphology in handsheets

Nordic Pulp & Paper Research Journal ◽

10.3183/npprj-2012-27-02-p264-269 ◽

2012 ◽

Vol 27 (2) ◽

pp. 264-269 ◽

Cited By ~ 9

Author(s):

Christian Lorbach ◽

Ulrich Hirn ◽

Johannes Kritzinger ◽

Wolfgang Bauer

Keyword(s):

Image Analysis ◽

Cross Section ◽

Cross Sections ◽

Image Plane ◽

3D Measurement ◽

Cross Sectional ◽

Fiber Cross Section ◽

Fiber Wall ◽

Sectional Shape ◽

Cross Section Geometry

Abstract We present a method for 3D measurement of fiber cross sectional morphology from handsheets. An automated procedure is used to acquire 3D datasets of fiber cross sectional images using an automated microtome and light microscopy. The fiber cross section geometry is extracted using digital image analysis. Simple sample preparation and highly automated image acquisition and image analysis are providing an efficient tool to analyze large samples. It is demonstrated that if fibers are tilted towards the image plane the images of fiber cross sections are always larger than the true fiber cross section geometry. In our analysis the tilting angles of the fibers to the image plane are measured. The resulting fiber cross sectional images are distorted to compensate the error due to fiber tilt, restoring the true fiber cross sectional shape. We use an approximated correction, the paper provides error estimates of the approximation. Measurement results for fiber wall thickness, fiber coarseness and fiber collapse are presented for one hardwood and one softwood pulp.

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On the effect of cross sectional shape on incipient motion and deposition of sediments in fixed bed channels

Journal of Hydrology and Hydromechanics ◽

10.2478/johh-2014-0003 ◽

2014 ◽

Vol 62 (1) ◽

pp. 75-81 ◽

Cited By ~ 10

Author(s):

Mir-Jafar-Sadegh Safari ◽

Mirali Mohammadi ◽

Golezar Gilanizadehdizaj

Keyword(s):

Cross Sections ◽

Research Work ◽

Fixed Bed ◽

Deposition Condition ◽

Incipient Motion ◽

Rigid Boundary ◽

Cross Sectional ◽

Motion Equations ◽

Sectional Shape ◽

Minimum Velocity

Abstract The condition of incipient motion and deposition are of the essential issues for the study of sediment transport. This phenomenon is of great importance to hydraulic engineers for designing sewers, drainage, as well as other rigid boundary channels. This is a study carried out with the objectives of describing the effect of cross-sectional shape on incipient motion and deposition of particles in rigid boundary channels. In this research work, the experimental data given by Loveless (1992) and Mohammadi (2005) are used. On the basis of the critical velocity approach, a new incipient motion equation for a V-shaped bottom channel and incipient deposition of sediment particles equations for rigid boundary channels having circular, rectangular, and U-shaped cross sections are obtained. New equations were compared to the other incipient motion equations. The result shows that the cross-sectional shape is an important factor for defining the minimum velocity for no-deposit particles. This study also distinguishes incipient motion of particles from incipient deposition for particles. The results may be useful for designing fixed bed channels with a limited deposition condition.

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Enamel Crystal Shape: History of an Idea

Advances in Dental Research ◽

10.1177/08959374870010022401 ◽

1987 ◽

Vol 1 (2) ◽

pp. 322-329 ◽

Cited By ~ 5

Author(s):

H. Warshawsky

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Cross Sections ◽

Three Dimensional ◽

Unit Cell ◽

Cross Sectional ◽

Transmission Electron ◽

History Of ◽

Sectional Shape ◽

Imaging Plane

The purpose of this paper is to review evidence which casts doubt on the interpretation universally applied to hexagonal images seen in sectioned enamel. The evidence is based on two possible models to explain the hexagonal profiles seen in mammalian enamel with transmission electron microscopy. The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons. The "rectangular ribbon" model proposes that hexagonal profiles are caused by three-dimensional segments that are parallelepipeds contained in the Epon section. Since shadow projections of such rectangular segments give angles that are inconsistent with the hexagonal unit cell, a model based on ribbons with rhomboidal cut ends and angles of 60 and 120° is proposed. The "rhomboidal ribbon" model projects shadows with angles that are predicted by the unit cell. It is suggested that segments of such crystallites in section project as opaque hexagons on the imaging plane in routine transmission electron microscopy. Morphological observations on crystallites in sections - together with predictions from the hexagonal, rectangular, and rhomboidal ribbon models - indicate that crystallites in rat incisor enamel are flat ribbons with rhomboidal cross-sectional shape. Hexagonal images in electron micrographs of thin-sectioned enamel can result from rhomboidal-ended, parallelepiped-shaped segments of these crystallites projected and viewed as two-dimensional shadows.

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A Method of Form Selection for Large Scale Structures

Volume 4: 14th International Conference on Design Theory and Methodology, Integrated Systems Design, and Engineering Design and Culture ◽

10.1115/detc2002/dtm-34011 ◽

2002 ◽

Author(s):

Damiano Pasini ◽

S. C. Burgess ◽

D. J. Smith

Keyword(s):

Cross Sections ◽

Large Scale ◽

Design Parameters ◽

Cross Sectional ◽

Geometrical Properties ◽

Large Scale Structures ◽

Shape Selection ◽

Efficiency Parameter ◽

Sectional Shape ◽

Selection Of

This paper presents a new method for modelling the efficiency of large-scale structural forms. Parametric equations, which include all design parameters and also the effect of buckling, are developed. Shape transformers, envelope efficiency parameter and scaling factor are introduced to describe the geometrical properties of cross-sections and to allow interaction between form and cross-sectional shape selection. Design charts provide insight and understanding and assist the selection of different structural concepts at the preliminary stage of design.

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Influence of the volute cross-sectional shape on mixed inflow turbine performances

Advances in Mechanical Engineering ◽

10.1177/1687814017708174 ◽

2017 ◽

Vol 9 (7) ◽

pp. 168781401770817 ◽

Cited By ~ 4

Author(s):

Mohamed Amine Meghnine ◽

Mohammad Kamal Hamidou ◽

Mohammed Hamel

Keyword(s):

Cross Sections ◽

Radial Direction ◽

Essential Element ◽

Sectional Area ◽

Cross Sectional ◽

Flow Angle ◽

Absolute Flow ◽

Subsonic Regime ◽

Simulation Results ◽

Sectional Shape

The volute is an essential element in the centrifugal machines. Improving its performance is an effective way to improve the total performance of the turbine. The purpose of this study is to replace the accelerating and guiding nozzle vanes by exploring different design possibilities on the cross-sectional area convergence of the volute, since a decreasing area is then associated with expansion in the subsonic regime. The work is extended to a mixed inflow turbine using the new volute cross sections under pulsating regimes for turbocharging. The numerical simulation results show larger accelerations [Formula: see text] and lesser losses in the case of sections with flatter area in the radial direction and without vaneless space between the volute and the rotor; but this combination has an effect on the exit absolute flow angle which is less uniform.

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Optimum design of cross-sectional sizes for thin steel plate columns considering buckling using the finite strip method and evolutionary computing

Transactions of the JSME (in Japanese) ◽

10.1299/transjsme.17-00212 ◽

2017 ◽

Vol 83 (854) ◽

pp. 17-00212-17-00212

Author(s):

Jiro SAKAMOTO ◽

Keisuke KOBAYASHI ◽

Satoshi KITAYAMA ◽

Nobutaka SHIMIZU

Keyword(s):

Optimum Design ◽

Steel Plate ◽

Evolutionary Computing ◽

Cross Sectional ◽

Finite Strip ◽

Strip Method ◽

Finite Strip Method ◽

Thin Steel ◽

Thin Steel Plate

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Wind-induced instability of structures

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1971.0040 ◽

1971 ◽

Vol 269 (1199) ◽

pp. 395-413 ◽

Cited By ~ 53

Keyword(s):

Wind Speed ◽

Cross Sections ◽

Natural Frequencies ◽

Structural Response ◽

Cross Sectional ◽

Periodic Surface ◽

Speed Range ◽

Aerodynamic Instability ◽

Sectional Shape ◽

Transverse Galloping

Forms of wind-induced instability of structures are described, and two of these, typical of long bodies with bluff cross-sections, are selected for more detailed consideration. The first is vortex-induced bending oscillation, a type of resonant response to the periodic surface pressure loading caused by the discrete wake vortex street formed from the shear layers separating from the bluff cross-section. Oscillation phenomena are described, including capture of the vortex frequency by the structural response frequency over a discrete wind speed range and amplification and phase shift of the loading over this range. The second form is transverse galloping, arising from aerodynamic instability of the bluff cross-sectional shape, so that small-amplitude oscillations generate forces which increase the amplitudes to large values. Oscillation phenomena are described, including the occurrence at very nearly natural frequencies, and the relatively large amplitudes (compared to vortex-induced oscillations) increasing with wind speed beyond a critical wind speed dependent on the level o fstructural damping. Effects of body and wind parameters on both forms of oscillation are considered, and methods of analysis and suppression for susceptible structures are described. Some probable future requirements and prospects are considered.

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Twist-to-bend ratio: an important selective factor for many rod-shaped biological structures

Scientific Reports ◽

10.1038/s41598-019-52878-z ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Steve Wolff-Vorbeck ◽

Max Langer ◽

Olga Speck ◽

Thomas Speck ◽

Patrick Dondl

Keyword(s):

Cross Sections ◽

Phase Field ◽

Material Properties ◽

Flexural Rigidity ◽

Torsional Rigidity ◽

Cross Sectional ◽

Deep Groove ◽

Biological Structures ◽

The Cross ◽

Sectional Shape

AbstractMechanical optimisation plays a key role in living beings either as an immediate response of individuals or as an evolutionary adaptation of populations to changing environmental conditions. Since biological structures are the result of multifunctional evolutionary constraints, the dimensionless twist-to-bend ratio is particularly meaningful because it provides information about the ratio of flexural rigidity to torsional rigidity determined by both material properties (bending and shear modulus) and morphometric parameters (axial and polar second moment of area). The determination of the mutual contributions of material properties and structural arrangements (geometry) or their ontogenetic alteration to the overall mechanical functionality of biological structures is difficult. Numerical methods in the form of gradient flows of phase field functionals offer a means of addressing this question and of analysing the influence of the cross-sectional shape of the main load-bearing structures on the mechanical functionality. Three phase field simulations were carried out showing good agreement with the cross-sections found in selected plants: (i) U-shaped cross-sections comparable with those of Musa sp. petioles, (ii) star-shaped cross-sections with deep grooves as can be found in the lianoid wood of Condylocarpon guianense stems, and (iii) flat elliptic cross-sections with one deep groove comparable with the cross-sections of the climbing ribbon-shaped stems of Bauhinia guianensis.

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Forming Process of Wire and Arc Additive Manufacture

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1035.198 ◽

2021 ◽

Vol 1035 ◽

pp. 198-205

Author(s):

Lei Zou ◽

Lei Li ◽

Jian Hua Cai ◽

Hai Ying Yang ◽

Jun Chen

Keyword(s):

Cross Sections ◽

Single Layer ◽

Weld Bead ◽

Additive Manufacture ◽

Feed Speed ◽

Forming Process ◽

Cross Sectional ◽

Weld Current ◽

Wire Feed Speed ◽

The Cross

The forming process of wire and arc additively manufacture (WAAM) was studied using the self-developed and designed WAAM system. The single-pass and single-layer weld bead samples were prepared with different process parameters, and the cross-sectional dimensions of the weld bead were measured. The influence rules of weld current, welding speed, wire feed speed and welding height on the weld bead size were obtained. In addition, the overlap experiment of the WAAM forming process was also carried out. The multiple and multilayer lap samples with different overlap rates were prepared, and the cross-sections of the lap samples were observed and analyzed. Finally, the overlap rate range of 35-45% with good forming effect was obtained.

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