The Bending of Curved Pipes With Variable Wall Thickness

2003 ◽  
Vol 70 (2) ◽  
pp. 253-259 ◽  
Author(s):  
V. P. Cherniy
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Shell Theory ◽  
Neutral Line ◽  
Radius Of Curvature ◽  
Curved Pipes ◽  
Variable Wall Thickness ◽  
Previous Solution ◽  
Variable Wall ◽  
Thin Shell Theory

A general solution is presented for the in-plane bending of short-radius curved pipes (pipe bends) which have variable wall thickness. Using the elastic thin-shell theory, the actual radius of curvature of the pipe’s longitudinal fibers and displacement of the neutral line of the cross section under bending are taken into account. The pipe’s wall thickness is assumed to vary smoothly along the contour of the pipe’s cross section, and is a function of an angular coordinate. The solution uses the minimization of the total energy, and is compared to our previous solution for curved pipes with constant wall thickness.

scholarly journals Extrusion of magnesium alloy hollow profiles with axial variable wall thickness

2019 ◽  
Author(s):  
Maik Negendank ◽  
Vidal Sanabria ◽  
Sören Müller ◽  
W. Reimers
Keyword(s):  
Magnesium Alloy ◽  
Wall Thickness ◽  
Variable Wall Thickness ◽  
Variable Wall

Obtaining Body Parts with Variable Wall Thickness Along the Perimeter

2021 ◽  
pp. 473-479
Author(s):  
Yuliya Bessmertnaya ◽  
Alexander Malyshev ◽  
Vladimir Vikhorev ◽  
Pavel Romanov
Keyword(s):  
Wall Thickness ◽  
Body Parts ◽  
Variable Wall Thickness ◽  
Variable Wall

Effect of Precompression on Thickness of Pipe During Bending

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
A. V. Kale ◽  
H. T. Thorat
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Horizontal Plane ◽  
Circular Cross Section ◽  
Thickness Variation ◽  
Parallel Plates ◽  
Thickness Change ◽  
Maximum Deformation ◽  
Curved Pipes ◽  
Tension And Compression

Straight pipes with a circular cross section are processed into smooth bends by various pipe bending techniques. After bending, the initial circular cross section is deformed with thickness change. These changes from ideal are normally referred to as “ovality” and “thinning.” Their influence on the subsequent behavior of curved pipes is not yet fully understood. The aim of this paper is to present a factual method to reduce thinning of the wall thickness of pipe during bending. A new mechanism is developed for bending of pipes. This mechanism has a provision of precompression (radial squeeze) of the pipe along the directrix of maximum deformation during bending. This is achieved by clamping the pipe using two parallel plates from top and bottom. In fact, the pipe is wrapped using two rollers—one from inside and one from outside in the horizontal plane—and two plates parallel to the horizontal plane—one from the top and one from the bottom. Experimentation is carried out on this mechanism, and thicknesses are measured at the grid points along the length of the pipe. From the experimental values of thicknesses on the tension and compression sides, dimensionless variations in wall thickness of various groups of pipes are computed for different precompression values. In order to represent the thickness at any point, a mathematical equation is derived. Analytical values of thickness variations on tension and compression sides are computed using this equation. Experimental and analytical results are compared, and its methodical approach is presented in this paper. Results show that precompression reduces thickness variation of the pipe after bending.

Comparison of Three Methods of MOM, MLFMM and PO/MOM for Simulation of Variable Wall Thickness Radome

2011 ◽  
Vol 268-270 ◽  
pp. 946-949
Author(s):  
Lie Zhang ◽  
Juan Zhang ◽  
Peng Fei Du ◽  
Zuo Jun Li ◽  
Zhu Feng Yue
Keyword(s):  
Wall Thickness ◽  
Method Of Moments ◽  
Variable Thickness ◽  
Fast Multipole Method ◽  
Design Concept ◽  
Physical Optics ◽  
Medium Size ◽  
Method Of Moment ◽  
Variable Wall Thickness ◽  
Variable Wall

a Design Concept of Piecewise Variable Wall Thickness of Radome Is Proposed to Simulate the Radome which Has Variable Wall. the Paper Calculates the Far Field of a Medium-Size Radome in the Case of Piecewise Variable Thickness by Three Methods as Follows: Method of Moment (MOM), Multilevel Fast Multipole Method (MLFMM) and Physical Optics& the Method of Moments (PO/MOM) Respectively. after Comparing the Results, we Find that the PO/MOM Method Have the Superiority in Simulation of Radome’s Electromagnetic because it’s More Accuracy and Less Memory Consuming than the other Two Methods. Also it Proves the Feasibility of the Design Concept of Piecewise Variable Thickness for Radome.

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