Identification of cross-section loads for steel beam with simple cross-sectional shape based on measured strain and its application

2020 ◽  
Vol 34 (12) ◽  
pp. 5017-5028
Author(s):  
Qingyi Xiang ◽  
Pengmin Lu ◽  
Binhua Wang
Keyword(s):  
Cross Section ◽  
Steel Beam ◽  
Cross Sectional ◽  
Measured Strain ◽  
Sectional Shape

Automated 3D measurement of fiber cross section morphology in handsheets

2012 ◽  
Vol 27 (2) ◽  
pp. 264-269 ◽  
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.

scholarly journals An atomic resolution study of precipitates in an Al-Ge Alloy

1986 ◽  
Vol 44 ◽  
pp. 538-539
Author(s):  
U. Dahmen ◽  
C. Nelson ◽  
K.H. Westmacott
Keyword(s):  
Cross Section ◽  
Atomic Resolution ◽  
Face Centered Cubic ◽  
Orientation Relationships ◽  
Cross Sectional ◽  
The Past ◽  
Moiré Fringes ◽  
Typical Aspect ◽  
Face Centered ◽  
Sectional Shape

The difficulty of precipitating germanium in dilute aluminum-germanium alloys is due to a large difference in crystal structures (face-centered cubic and diamond cubic) accompanied by a substantial volume expansion of 36%. A great variety of precipitate morphologies and orientation relationships are observed. A frequently found morphology is that of <100> needles. By selected area diffraction and Moire fringes it has been established that <100> Al and <110> Ge are parallel along the needle axis. The typical aspect ratio of about 100 has made it difficult in the past to investigate the cross-sectional shape and internal structure of these needles, although some indications of internal twinning were found in plates. in the present work, the Berkeley Atomic Resolution Microscope was used to examine needles in cross section by imaging along the <110> Ge <100> Al needle axis.

scholarly journals Optimization of the cross-sectional shape of the belts of trihedral lattice supports

2019 ◽  
Vol 7 (4) ◽  
pp. 5-8
Author(s):  
Linar Sabitov ◽  
Ilnar Baderddinov ◽  
Anton Chepurnenko
Keyword(s):  
Objective Function ◽  
Nonlinear Optimization ◽  
Cross Section ◽  
Optimization Methods ◽  
Cross Sectional ◽  
Maximum Value ◽  
Axial Moment ◽  
The Cross ◽  
Nonlinear Optimization Methods ◽  
Sectional Shape

The article considers the problem of optimizing the geometric parameters of the cross section of the belts of a trihedral lattice support in the shape of a pentagon. The axial moment of inertia is taken as the objective function. Relations are found between the dimensions of the pentagonal cross section at which the objective function takes the maximum value. We introduce restrictions on the constancy of the consumption of material, as well as the condition of equal stability. The solution is performed using nonlinear optimization methods in the Matlab environment.

Numerical study for the improvement of bead spreading architecture with modified nozzle geometries in additive manufacturing of polymers

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Easir Arafat Papon ◽  
Anwarul Haque ◽  
Muhammad Ali Rob Sharif
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
3D Printing ◽  
Cross Section ◽  
Nozzle Exit ◽  
Cross Sectional ◽  
Content Type ◽  
The Cross ◽  
Viscous Polymer ◽  
Sectional Shape

Purpose This paper aims to develop a numerical model of bead spreading architecture of a viscous polymer in fused filament fabrication (FFF) process with different nozzle geometry. This paper also focuses on the manufacturing feasibility of the nozzles and 3D printing of the molten beads using the developed nozzles. Design/methodology/approach The flow of a highly viscous polymer from a nozzle, the melt expansion in free space and the deposition of the melt on a moving platform are captured using the FLUENT volume of fluid (VOF) method based computational fluid dynamics code. The free surface motion of the material is captured in VOF, which is governed by the hydrodynamics of the two-phase flow. The phases involved in the numerical model are liquid polymer and air. A laminar, non-Newtonian and non-isothermal flow is assumed. Under such assumptions, the spreading characteristic of the polymer is simulated with different nozzle-exit geometries. The governing equations are solved on a regular stationary grid following a transient algorithm, where the boundary between the polymer and the air is tracked by piecewise linear interface construction (PLIC) to reconstruct the free surface. The prototype nozzles were also manufactured, and the deposition of the molten beads on a flatbed was performed using a commercial 3D printer. The deposited bead cross-sections were examined through optical microscopic examination, and the cross-sectional profiles were compared with those obtained in the numerical simulations. Findings The numerical model successfully predicted the spreading characteristics and the cross-sectional shape of the extruded bead. The cross-sectional shape of the bead varied from elliptical (with circular nozzle) to trapezoidal (with square and star nozzles) where the top and bottom surfaces are significantly flattened (which is desirable to reduce the void spaces in the cross-section). The numerical model yielded a good approximation of the bead cross-section, capturing most of the geometric features of the bead with a reasonable qualitative agreement compared to the experiment. The quantitative comparison of the cross-sectional profiles against experimental observation also indicated a favorable agreement. The significant improvement observed in the bead cross-section with the square and star nozzles is the flattening of the surfaces. Originality/value The developed numerical algorithm attempts to address the fundamental challenge of voids and bonding in the FFF process. It presents a new approach to increase the inter-bead bonding and reduce the inter-bead voids in 3D printing of polymers by modifying the bead cross-sectional shape through the modification of nozzle exit-geometry. The change in bead cross-sectional shape from elliptical (circular) to trapezoidal (square and star) cross-section is supposed to increase the contact surface area and inter-bead bonding while in contact with adjacent beads.

Simulasi Perancangan Drainase Muka Tanah pada Bandar Udara Achmad Yani Semarang Sebagai Salah Satu Usaha Pencegahan Banjir

WARTA ARDHIA ◽  
2013 ◽  
Vol 39 (4) ◽  
pp. 305-316
Author(s):  
Ataline Muliasari ◽  
Lupi Wahyuningsih
Keyword(s):  
Surface Water ◽  
Cross Section ◽  
Land Surface ◽  
Drainage Channel ◽  
Water Drainage ◽  
Hydraulic Radius ◽  
Channel Depth ◽  
Cross Sectional ◽  
Surface Drainage ◽  
Sectional Shape

Drainage is defined as surface water drainage, either by gravity or by pump which aims to prevent inundation, maintain and lower the water level im order to avoid the amount of water. Ahmad Yani Airport has a poor drainage systems. Furthermore, land subsidence in Semarang area potential for experiencing flooding when the rainy season with a fairly high rainfall. Based on the results of processing the data showed that it is needed the land surface drainage channel with a cross-sectional shape of a trapezium. When the width of the base of the cross section is 3 meters , then the required channel depth is 3.9 meters with a hydraulic radius is 0.82-meter, and hydraulic depth is 3.05 meters. Drainase didefinisikan sebagai pembuangan air permukaan, baik secara gravitasi maupun dengan pompa yang bertujuan untuk mencegah terjadinya genangan, menjaga dan menurunkan permukaan air sehingga genangan air dapat dihindarkan. Bandar Udara Ahmad Yani dengan kondisi sistem drainase yang kurang baik dan penurunan permukaan tanah di wilayah Semarang, maka bila musim penghujan tiba dengan curah hujan yang cukup tinggi selalu berpotensi untuk mengalami banjir. Berdasarkan hasil pengolahan data juga didapatkan hasil bahwa untuk menyesuaikan antara curah hujan di wilayah Semarang dengan luas area Bandar udara Achmad Yani diperlukan saluran drainase muka tanah berupa saluran dengan bentuk penampang trapezium. Bila lebar dasar dari penampang trapezim tersebut adalah 3 meter, maka diperlukan saluran sedalam 3,9 meter dengan Jari-jari hydraulic 0,82 meter, dan kedalaman hydraulic 3,05 meter.

scholarly journals Analytical Model of a Multi-Step Straightening Process for Linear Guideways Considering Neutral Axis Deviation

Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 316 ◽  
Author(s):  
Yongquan Zhang ◽  
Hong Lu ◽  
He Ling ◽  
Yang Lian ◽  
Mingtian Ma
Keyword(s):  
Analytical Model ◽  
Cross Section ◽  
Predictive Accuracy ◽  
Neutral Axis ◽  
Longitudinal Stress ◽  
Linear Superposition ◽  
Element Analysis ◽  
Cross Sectional ◽  
The Cross ◽  
Sectional Shape

The cross-sectional shape of a linear guideway has been processed before the straightening process. The cross-section features influence not only the position of the neutral axis, but also the applied and residual stresses along the longitudinal direction, especially in a multi-step straightening process. This paper aims to present an analytical model based on elasto-plastic theory and three-point reverse bending theory to predict straightening stroke and longitudinal stress distribution during the multi-step straightening process of linear guideways. The deviation of the neutral axis is first analyzed considering the asymmetrical features of the cross-section. Owing to the cyclic loading during the multi-step straightening process, the longitudinal stress curves are then calculated using the linear superposition of stresses. Based on the cross-section features and the superposition of stresses, the bending moment is corrected to improve the predictive accuracy of the multi-step straightening process. Finite element analysis, as well as straightening experiments, have been performed to verify the applicability of the analytical model. The proposed approach can be implemented in the multi-step straightening process of linear guideways with similar cross-sectional shape to improve the straightening accuracy.

Erythrocyte Sedimentation Rates in Inclined Vessels

1973 ◽  
Vol 51 (9) ◽  
pp. 685-690 ◽  
Author(s):  
R. N. O'Brien ◽  
M. B. Hocking ◽  
P. McOrmond ◽  
K. R. Thornton
Keyword(s):  
Cross Section ◽  
Sedimentation Rates ◽  
Settling Rate ◽  
Cross Sectional ◽  
Erythrocyte Sedimentation ◽  
The Cross ◽  
Sectional Shape ◽  
Erythrocyte Sedimentation Rates ◽  
Test Rack ◽  
Settling Rates

The rates of erythrocyte settling have been investigated in round and square cross-section tubes, vertically; and at nine different angles; and with the square tubes flat and on edge, to a minimum of 15° from the horizontal. Apparent settling rates increased as the angle from the horizontal decreased. Real settling rates (vertical settling rates) increased sharply on decreasing the angle from the horizontal, to a maximum at about 60°, and then decreased less abruptly for the shallower angles. The cross-sectional shape of the tube did not significantly affect the settling rates of erythrocytes. Settling in inclined tubes proceeds fast enough to permit clinical erythrocyte settling rate (E.S.R.) tests to be carried out in 10 min in place of the usual 60 min. If the standard E.S.R. test rack deviates as little as 5° from the vertical it can cause the observed settling rates to double relative to readings obtained on a vertical rack.

Simulation Research on Bonded Microchannel Deformation of Polymer Microfluidic Chip

2012 ◽  
Vol 246-247 ◽  
pp. 1204-1208
Author(s):  
Lei Huang ◽  
Zhang Wang ◽  
Chun Peng Chu ◽  
Bing Yan Jiang
Keyword(s):  
Cross Section ◽  
Dimensional Accuracy ◽  
Microfluidic Chips ◽  
Cross Sectional ◽  
Simulation Research ◽  
Software Simulation ◽  
Finite Element Software ◽  
Varied Temperature ◽  
Bonding Method ◽  
Sectional Shape

A new bonding method of microfluidic chips, bonding in-mold, was presented. Finite element software simulation was used to study the deformation of microchannels in poly methyl methacrylate (PMMA) bonded chips. Varied temperature and compression thickness have been taken into account. Results showed that bonded microchannel cannot maintain the cross-sectional shape and dimensional accuracy. The area of cross-section was smaller. Its height changes since the substrate’s raised up and the cover plate’s bulged down. But the width dimension of microchannel was essentially unchanged. The deformation caused by thermal expansion is small. Experimental data show that compressed thickness has a greater impact than temperature.

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