scholarly journals Effect of Pocket Height on Aluminum flow through zero-bearing extrusion dies to produce single solid profile using FEM Simulation: تأثير ارتفاع المغذي على تدفق الألمنيوم عبر قوالب البثق ذات سطح الضبط الصفري لإنتاج مقطع مصمت مفرد بطريقة العناصر المنتهية

2020 ◽  
Vol 4 (4) ◽  
Author(s):  
Mohammad Majed Altaleb, Almohannad Makki
Keyword(s):  
Fem Simulation ◽  
Practical Experience ◽  
Aluminum Extrusion ◽  
Forming Process ◽  
Rectangular Section ◽  
Cross Sectional ◽  
Extrusion Dies ◽  
Flow Through ◽  
Feeder Design ◽  
Relative Flow

Extrusion is known as an industrial forming process for producing long sections with a fixed cross-sectional area and is often used to extrude colored metals, especially aluminum. The aluminum rods (Billets) are heated and pressed through a die to obtain the required profile. The research aims to study the effect of Pocket height when using zero bearing dies by modeling using the INSPIRE EXTRUDE METAL program package for a single rectangular section of 65 mm in length and 1.5 mm in width, and then to conduct experimental verification of the results by designing, manufacturing and testing a real mold in an aluminum extrusion factory that matches one of the molds Studied. As we studied a group of molds that have a Pocket so that the height of the pocket in them changes from zero (a reference flat die) to a height of 20 mm. The feeder design takes into account the homogenization of the flow across the studied section, which narrows in the center and widens at the edges. The measurement of the relative flow velocity at the front of the section was used as an indicator to analyze the results of the analytical experiment. The study showed that a certain height of the feeder of 10 mm must be maintained for the studied section. The FEM results and the practical experience were identical. This shows the importance of the FEM and its effectiveness in shortening the experimental work and that it can, to a large extent, save time and effort to manufacture, test and correct dies.

Experimental and Numerical Analysis of Titanium Microtube Elliptical Flaring

2010 ◽  
Author(s):  
Weichao Wu ◽  
Ying Huang ◽  
Rajiv Malhotra ◽  
Yongjun Wang ◽  
Jian Cao
Keyword(s):  
Analytical Model ◽  
Cross Section ◽  
Fem Simulation ◽  
Circular Cross Section ◽  
Forming Process ◽  
Cross Sectional ◽  
Elliptical Cross ◽  
Tube Flaring ◽  
Sectional Shape ◽  
The Relationship

Traditional tube flaring processes focuses on expanding one end of the tube without changing its cross-sectional shape. This paper presents a new two-step tube flaring process for expanding one end of a titanium alloy microtube while simultaneously changing its cross-sectional shape from circular to elliptical. Experiments were performed to investigate and verify this process. Furthermore, an analytical model was developed to analyze the forming process and investigate the relationship between punch feed and maximum plastic strain during the flaring process. The analysis shows that the two-step flaring process used is effective in expanding the circular cross section to an elliptical cross section without failure. It is also shown that the developed analytical model can predict the fracture of the tube end during the flaring process approximately. Finally, a FEM simulation was performed to further investigate the two-step flaring process.

Modelling of Neutral Line Parameter for Sheet Metal Stamping and Roll Forming Processes

2020 ◽  
Vol 311 ◽  
pp. 41-47
Author(s):  
Bao Shan Wang ◽  
Jing Chen ◽  
Cheng Hsien Yu ◽  
Jinn Jong Sheu
Keyword(s):  
Sheet Metal ◽  
Neutral Line ◽  
Fem Simulation ◽  
Sheet Thickness ◽  
Roll Forming ◽  
Line Position ◽  
Forming Process ◽  
Cross Sectional ◽  
Line Parameter ◽  
The Mean

The blank development of sheet metal for the stamping and the roll forming processes is crucial for the dimensional accuracy of the products. The neutral line parameter is the indicator to present the thinning phenomenon at the bending corners of the products. The basic assumption of the neutral line position is the surface that the sheet metal remains un-deformed after the stamping or the roll forming process. The conventional determination method of the neutral line position is based on the zero strain position through the thickness direction of the blank. In this paper, a different neutral line factor calculation method based on the mean profile length was proposed to find the neutral line factor, which is directly related to the profile length and more precise for the bland development calculation. A cross sectional profile was obtained after the forming process and the mean profile length of the upper and the lower surface was obtained. The ratios of the bending radius to the sheet thickness were calculated using the FEM simulation. A neutral line equation was proposed considering the material mechanical properties and the bending tool parameters. The initial blank width was compared to the forming result of the CAE simulation to validate the neutral line model. This model is able to take into consideration of the thinning effect at the entire bending zone of the metal forming without the assumption of the uniform thinning and is more accuracy for the blank width calculation.

scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Two Phase ◽  
Cross Sectional ◽  
Flow Through ◽  
Pvc Pipe ◽  
Phase Water

What Industry Wants: An Empirical Analysis of Health Informatics Job Postings

2021 ◽  
Vol 12 (02) ◽  
pp. 285-292
Author(s):  
Tara M. McLane ◽  
Robert Hoyt ◽  
Chad Hodge ◽  
Elizabeth Weinfurter ◽  
Erin E. Reardon ◽  
...  
Keyword(s):  
Empirical Analysis ◽  
Health Informatics ◽  
Formal Education ◽  
Practical Experience ◽  
The United States ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Education Levels ◽  
Clinical Background ◽  
Job Postings

Abstract Objectives To describe the education, experience, skills, and knowledge required for health informatics jobs in the United States. Methods Health informatics job postings (n = 206) from Indeed.com on April 14, 2020 were analyzed in an empirical analysis, with the abstraction of attributes relating to requirements for average years and types of experience, minimum and desired education, licensure, certification, and informatics skills. Results A large percentage (76.2%) of posts were for clinical informaticians, with 62.1% of posts requiring a minimum of a bachelor's education. Registered nurse (RN) licensure was required for 40.8% of posts, and only 7.3% required formal education in health informatics. The average experience overall was 1.6 years (standard deviation = 2.2), with bachelor's and master's education levels increasing mean experience to 3.5 and 5.8 years, respectively. Electronic health record support, training, and other clinical systems were the most sought-after skills. Conclusion This cross-sectional study revealed the importance of a clinical background as an entree into health informatics positions, with RN licensure and clinical experience as common requirements. The finding that informatics-specific graduate education was rarely required may indicate that there is a lack of alignment between academia and industry, with practical experience preferred over specific curricular components. Clarity and shared understanding of terms across academia and industry are needed for defining and advancing the preparation for and practice of health informatics.

Thermally developing forced convection flow through porous concentric pipes annular duct

2021 ◽  
pp. 095440622110022
Author(s):  
Farhan Ahmed
Keyword(s):  
Flow Region ◽  
Axial Direction ◽  
Darcy Number ◽  
Convection Flow ◽  
Axial Distance ◽  
Cross Sectional ◽  
Developing Flow ◽  
Annular Sector ◽  
Flow Through ◽  
The Cross

This article shows the thermally developing flow through concentric pipes annular sector duct by describing the Darcy Brinkman flow field. The cross sectional convection-diffusion terms are transformed in power law discretized form by integrating over the differential volume, whereas backward difference scheme is used in the axial direction of heat flow. With the help of semi implicit method for pressure linked equations-revised ( SIMPLE-R), we get the solution of the governing problem. The graphs of velocity profiles against R and average Nusselt number against axial distance are plotted for different values of Darcy number and geometrical configuration parameters. It has been pointed out that velocity and thermal entrance length decrease, when we decrease the value of Darcy number. By decreasing the cross section of the concentric pipes annular sector duct in the transverse direction, thermally fully developed flow region develops earlier.

Increased Productivity in Hot Aluminum Extrusion by Using Extrusion Dies with Inner Cooling Channels Manufactured by Rapid Tooling

2014 ◽  
Vol 611-612 ◽  
pp. 981-988 ◽  
Author(s):  
Ramona Hölker ◽  
Matthias Haase ◽  
Nooman Ben Khalifa ◽  
A. Erman Tekkaya
Keyword(s):  
Surface Defects ◽  
Experimental Investigations ◽  
Extrusion Force ◽  
Aluminum Extrusion ◽  
Thermally Induced ◽  
Manufacturing Method ◽  
Cooling Channels ◽  
Extrusion Dies ◽  
Exit Temperature ◽  
Tooling Technology

The influence of local inner die cooling on the heat balance in hot aluminum extrusion was investigated. For the manufacturing of the die with cooling channels close to the forming zone, the layer-laminated manufacturing method was applied. The new tooling technology was applied in order to decrease the profiles exit temperature and to avoid thermally induced surface defects with the aim to raise the productivity in hot aluminum extrusion processes. Numerical and experimental investigations revealed that, while maintaining the exit temperature of the extrudate, a distinct increase of the production speed up to 300% can be realized, while the extrusion force increases only slightly. An effect on the profiles microstructure was also detected. By applying die cooling, grain coarsening can be significantly limited or even be avoided.

Identification of the Location of Conductive Filaments Formed in Pt/NiO/Pt Resistive Switching Cells and Investigation on Their Properties

2012 ◽  
Vol 1430 ◽  
Author(s):  
Tatsuya Iwata ◽  
Yusuke Nishi ◽  
Tsunenobu Kimoto
Keyword(s):  
Resistive Switching ◽  
Chemical Properties ◽  
Cell Resistance ◽  
Forming Process ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Size And Shape

ABSTRACTExact locations of conductive filaments formed in NiO-based resistive switching (RS) cells were detected by C-AFM, and their electrical as well as chemical properties were investigated. After a forming process, a part of top electrodes of Pt/NiO/Pt RS cells is deformed. NiO layers are also deformed, and conductive spots, i.e. filaments have been found preferentially along the edges of deformations. Detailed C-AFM investigation has revealed that variation of cell resistances originates from differences in size and shape of filaments, not their resistivity. Furthermore, cross-sectional TEM analysis has demonstrated that filaments determining cell resistance consist of reduced NiO with an inclusion of Pt.

Microstructure Integrated Modeling of Multiscan Laser Forming

2002 ◽  
Vol 124 (2) ◽  
pp. 379-388 ◽  
Author(s):  
Jin Cheng ◽  
Y. Lawrence Yao
Keyword(s):  
Flow Stress ◽  
Numerical Models ◽  
Flow Behavior ◽  
Fem Simulation ◽  
Constitutive Models ◽  
Low Carbon Steel ◽  
Laser Forming ◽  
Low Carbon ◽  
Forming Process ◽  
Heating And Cooling

Laser forming of steel is a hot forming process with high heating and cooling rate, during which strain hardening, dynamic recrystallization, and phase transformation take place. Numerical models considering strain rate and temperature effects only usually give unsatisfactory results when applied to multiscan laser forming operations. This is mainly due to the inadequate constitutive models employed to describe the hot flow behavior. In this work, this limitation is overcome by considering the effects of microstructure change on the flow stress in laser forming processes of low carbon steel. The incorporation of such flow stress models with thermal mechanical FEM simulation increases numerical model accuracy in predicting geometry change and mechanical properties.

FEM Simulation Analysis of Cross Wedge Rolling Process

2011 ◽  
Vol 381 ◽  
pp. 72-75
Author(s):  
Bin Li
Keyword(s):  
Simulation Analysis ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Rolling Process ◽  
Stress Distributions ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Pressure Distributions ◽  
Metal Forming Process ◽  
Rolling Load

This paper investigates the interfacial slip between the forming tool and workpiece in a relatively new metal forming process, cross-wedge rolling. Based on the finite elements method, three-dimensional mechanical model of cross wedge rolling process has been developed. Examples of numerical simulation for strain, stress distributions and rolling load components have been included. The main advantages of the finite element method are: the capability of obtaining detailed solutions of the mechanics in a deforming body, namely, stresses, shapes, strains or contact pressure distributions; and the computer codes, can be used for a large variety of problems by simply changing the input data.

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