Analysis of Wire Drawing and Extrusion Through Conical Dies of Large Cone Angle

1964 ◽  
Vol 86 (4) ◽  
pp. 305-314 ◽  
Author(s):  
Betzalel Avitzur
Keyword(s):  
Cone Angle ◽  
Wire Drawing ◽  
Wire Radius ◽  
Yield Limit ◽  
Process Variables ◽  
Absolute Value ◽  
Direct Extension ◽  
Yield Value ◽  
Half Angle ◽  
Large Cone Angle

This work is a direct extension of reference [3]. There the problem was treated with the assumption that the cone angle was small. Here this limitation exists no more. The operations of wire drawing and extrusion through conical dies are treated on the assumption that “Mises” material is formed. An upper-bound solution is obtained for the drawing stress in wire drawing and for the pushing stress in extrusion. The effect of each of the process variables on these forces is presented graphically. The process variables are: the cone half-angle (α), initial (Ri) and final (Rf) wire radius, material yield limit (σ0) under uniaxial load, back pull (σxb) and front pull (σxf), coefficient of friction (μ) or shear factor (m), die land (L), exit velocity (vf), and entrance velocity (vi). On the assumption that the maximum front tension cannot exceed the yield limit of the material under uniaxial tension, a solution is obtained for maximum possible reduction in wire drawing. An analogous assumption, i.e., that the absolute value of the pushing stress also cannot exceed the yield value, gives a criterion for maximum possible reduction in extrusion.

Analysis of Wire Drawing and Extrusion Through Conical Dies of Small Cone Angle

1963 ◽  
Vol 85 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Betzalel Avitzur
Keyword(s):  
Cone Angle ◽  
Wire Drawing ◽  
Power Balance ◽  
Wire Radius ◽  
Process Variables ◽  
Power Losses ◽  
Uniaxial Load ◽  
The Wire ◽  
Analytical Expressions ◽  
Entrance Velocity

Analytical expressions are derived for the required front pull for wire drawing, as well as the back push for extrusion. The effect of each of the process variables on these forces is presented graphically. The process variables are: the cone’s semiangle (α) initial (Ri) and final (Rf) wire radius, material yield limit (σ0) at uniaxial load, back pull (σxb) and front pull (σxf), coefficient of friction (μ) or shear factor (m), die land (L), exit velocity (vf), and entrance velocity (vi). The power balance is set for these powers: (1) Internal power of deformation of the wire, (2) power involved with the back force on the wire, (3) power involved with the front force on the wire, (4) power losses due to friction between the wire and the die.

scholarly journals Optimization of inulin production process parameters using response surface methodology

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Wasim Akram ◽  
Navneet Garud
Keyword(s):  
Response Surface ◽  
Spray Drying ◽  
Product Yield ◽  
Drying Methods ◽  
Process Variables ◽  
Drying Process ◽  
Uniform Size ◽  
Drying Temperature ◽  
Yield Value ◽  
Internal Configuration

Abstract Background Chicory is one of the major source of inulin. In our study, Box–Behnken model/response surface analysis (RSM) was used for the optimization of spray drying process variables to get the maximum inulin yield from chicory (Cichorium intybus L.). For this investigation, the investigational plan utilized three process variables drying temperature (115–125 °C), creep speed (20–24 rpm), and pressure (0.02–0.04 MPa). Result The optimal variables established by applying the Box–Behnken model were as follows: drying temperature 119.20 °C, creep speed 21.64 rpm, and pressure 0.03 MPa. The obtained powdered inulin by spray drying was investigated for the yield value, identification, size, and surface morphology of the particle. The inulin obtained from the spray drying process consists of a fine molecule-sized white powder. Instead, the drying methods shows a significant effect on the morphology and internal configuration of the powdered inulin, as the inulin obtained from spray drying was of a widespread and uniform size and shape, with a rough surface on increase in temperature and smoother surface while increasing the creep speed. The findings indicate that the spray drying with optimum parameters resulted in maximum product yield. Conclusion The outcomes of the study concluded that the product yield through spray drying technique under optimized condition is optimal as compared to other drying technique. Hence, this technique may be applied at commercial scale for the production of inulin.

scholarly journals Evaluation of Algebraic Iterative Image Reconstruction Methods for Tetrahedron Beam Computed Tomography Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-14
Author(s):  
Joshua Kim ◽  
Huaiqun Guan ◽  
David Gersten ◽  
Tiezhi Zhang
Keyword(s):  
Computed Tomography ◽  
Iterative Reconstruction ◽  
Cone Angle ◽  
Iterative Algorithms ◽  
Projection Data ◽  
Reconstruction Algorithms ◽  
Reconstruction Methods ◽  
Large Cone Angle ◽  
Using Data ◽  
Dual Detector

Tetrahedron beam computed tomography (TBCT) performs volumetric imaging using a stack of fan beams generated by a multiple pixel X-ray source. While the TBCT system was designed to overcome the scatter and detector issues faced by cone beam computed tomography (CBCT), it still suffers the same large cone angle artifacts as CBCT due to the use of approximate reconstruction algorithms. It has been shown that iterative reconstruction algorithms are better able to model irregular system geometries and that algebraic iterative algorithms in particular have been able to reduce cone artifacts appearing at large cone angles. In this paper, the SART algorithm is modified for the use with the different TBCT geometries and is tested using both simulated projection data and data acquired using the TBCT benchtop system. The modified SART reconstruction algorithms were able to mitigate the effects of using data generated at large cone angles and were also able to reconstruct CT images without the introduction of artifacts due to either the longitudinal or transverse truncation in the data sets. Algebraic iterative reconstruction can be especially useful for dual-source dual-detector TBCT, wherein the cone angle is the largest in the center of the field of view.

scholarly journals FABRICATION OF LARGE CONE ANGLE OPTICAL FIBER PROBE BY DYNAMIC CHEMICAL ETCHING METHOD

2001 ◽  
Vol 50 (12) ◽  
pp. 2382
Author(s):  
SUN JIA-LIN ◽  
TIAN GUANG-YAN ◽  
LI QIN ◽  
ZHAO JUN ◽  
GUO JI-HUA ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Chemical Etching ◽  
Cone Angle ◽  
Fiber Probe ◽  
Optical Fiber Probe ◽  
Etching Method ◽  
Large Cone Angle
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