scholarly journals Experimental Study of Features of Thin-Walled Pipes Sizing in the Line of a Pipe Rolling Plant with an Automatic Mill

2021 ◽  
Vol 346 ◽  
pp. 01032
Author(s):  
S.Yu. Belyaev ◽  
A.A. Fedulov ◽  
Yu.M. Chernyshev ◽  
V.I. Kuznetsov ◽  
M.Yu. Bulganina
Keyword(s):  
Theoretical Analysis ◽  
Wall Thickness ◽  
Experimental Studies ◽  
Predictive Values ◽  
Strength Group ◽  
Automatic Mill ◽  
Thin Walled Pipe ◽  
Rolling Plant ◽  
Thin Walled ◽  
Increased Strength

The aim of the study is to establish the actual level of working loads on the roll drive line of the sizing mill installed as part of the PRP-220 with an automatic mill, when switching to the production of steel pipes from increased strength group. The study is based on a complex experimental and theoretical analysis. After the processing of the results of experimental studies a comparison of the most loaded sizing route for a thin-walled pipe with a diameter of 244.5 mm and a wall thickness of 8.9 mm (D/S = 27.5) made of steel of strength group “D” was made with the route for a pipe with a diameter of 177.8 mm and a wall thickness of 9.2 mm (D/S = 19.3) from steel of strength group “E”. Graphs of the observed processes are presented, as well as calculated predictive values of sizing of thin-walled pipes for steel of strength group “E”, obtained on the basis of an experimental-theoretical analysis of the growth of flow stress. Recommendations have been given for improving the equipment of the PRP-220 sizing mill for the production of pipes with increased diameters from steels of increased strength groups.

Experimental Study on Residual Cross-Sectional Flattening of Thin-Walled Pipes Under Pure Plastic Bending

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Ziqian Zhang
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Residual Deformation ◽  
Outer Diameter ◽  
Cross Sectional ◽  
Plastic Bending ◽  
Thin Walled Pipe ◽  
Bending Radius ◽  
Thin Walled ◽  
The Cross

Abstract Cross-sectional ovalization (ovalization) usually occurs when thin-walled pipe is subjected to large plastic bending. This paper is concerned with residual deformation of thin-walled pipe's cross section in a radial direction when external bending moment is removed. In order to clarify the fundamental ovalization characteristics, find out what factors influence the residual flattening (value of ovalization), the ovalization behavior is investigated experimentally. The experiments are carried out on 21 stainless steel specimens with different geometric parameters under different bending radii by means of a four-point pure bending device. The residual cross-sectional flattenings are monitored continuously by scanning the cross section periodically along the circumferential direction. From the experimental results, it is observed that the cross-sectional shape of the thin-walled pipe is not perfect standard ellipse, and the appearance of the maximum residual flattening is usually found in the direction normal to the neutral surface. It is also revealed the relationships between the residual flattening and the bending radius, the wall thickness, and the pipe outer diameter, i.e., the residual flattening increases as the bending radius and the wall thickness reduce, but it increases as the outer diameter increases. These results are expected to find their potential application in thin-walled pipe bending operation.

Minimum Weight of Tapered Round Thin-Walled Columns

1952 ◽  
Vol 19 (3) ◽  
pp. 375-380
Author(s):  
Morris Feigen
Keyword(s):  
Wall Thickness ◽  
Minimum Weight ◽  
Weight Ratio ◽  
Optimum Shape ◽  
Bending Stress ◽  
Round Tube ◽  
Cylindrical Column ◽  
Truncated Cone ◽  
Thin Walled ◽  
Tapered Column

Abstract It is shown that the optimum wall thickness of a cylindrical round tube column is a function of load only and is independent of diameter. The optimum wall thickness of a tapered round thin-walled column is found to be constant along its length. The optimum shape of a tapered round thin-walled column is derived, being that column whose bending stress in the buckled state is constant along its length. The weight ratio of the optimum tapered column to an equal-strength optimum cylindrical column is found to be 0.8924. It is shown that a double truncated cone whose diameter ratio is in the range 0.35 ⩽ D1/D2 ⩽ 0.50 closely approaches the optimum column. If it is specified that no portion of the double truncated cone shall yield, then the weight advantage of the cone over the cylindrical column is rapidly lost as the stress in the cylindrical column approaches the yield stress. In the inelastic range the weight advantage of the tapered column will be less than in the elastic range.

The Use of Advanced Aluminum Alloys for Enhanced Productivity in Plastic Injection Molding

2000 ◽  
Author(s):  
Jim Nerone ◽  
Karthik Ramani
Keyword(s):  
Aluminum Alloys ◽  
Injection Molding ◽  
Wall Thickness ◽  
Simulation Software ◽  
Cooling Time ◽  
Coolant Temperature ◽  
Steel Mold ◽  
Cooling Channels ◽  
Injection Molding Simulation ◽  
Increased Strength

Abstract New aluminum alloys, QC-7® and QE-7®, have thermal conductivities four times greater than traditional tool steels, and have significantly increased strength and hardness compared to traditional aluminum materials. Molds were constructed of P-20 tool steel and QE-7® aluminum and were used to provide experimental data regarding thermal mold characteristic and confirm injection molding simulation predictions using C-Mold®. The relationships between cooling time reduction (using aluminum alloys) and polymer type, cooling channel depth, part wall thickness, and coolant temperature were explored both experimentally and using simulation software. It was shown that the potential reduction in cooling time varied from 5% to 25%. The most significant percentage improvements were observed in parts with part wall thickness of 0.05″ to 0.10″ and in molds with cooling channels at a depth ratio (D/d) of 2.0. The thermal pulses in the steel mold 0.10″ from the surface were approximately 63% larger than in aluminum mold.

scholarly journals Theoretical and experimental studies of a gas stamping device with a piston pressure multiplier

2019 ◽  
Vol 18 (1) ◽  
pp. 163-173
Author(s):  
A. Yu. Botashev ◽  
R. A. Bayramukov
Keyword(s):  
Theoretical Analysis ◽  
Experimental Studies ◽  
Fuel Mixture ◽  
Small Scale ◽  
Scale Production ◽  
Pressure Treatment ◽  
Energy Of Combustion ◽  
Stamping Process ◽  
Pressure Multiplier ◽  
The Matrix

In many industries, the share of small-scale production plants is significant. In these conditions, compared with traditional methods of pressure treatment, pulse pressure treatment methods, one of the varieties of which is gas stamping, are more efficient. However, the known devices of gas stamping provide mainly stamping of thin-walled parts. To expand the technological capabilities of gas stamping, the authors developed a gas stamping device with a piston pressure multiplier, in which heating and deformation of the stamping workpiece is carried out using the energy of combustion of fuel mixtures in the combustion chamber, in the working cylinder and in the cavity of the matrix. This article is devoted to the study of the workflow of this device. Theoretical analysis of the workflow was carried out, and, as a result, a pattern was determined for the variation of the pressure that performs the stamping process in the working cylinder. In particular, it was found that at the final stage of the stamping process, due to the energy of combustion of the fuel mixture, the pressure in the working cylinder increases 1.5...2 times, which allows a significant increase in the thickness of the parts to be stamped. An experimental gas stamping device with a piston pressure multiplier was developed, and experimental studies were carried out. The studies confirmed the main results of the theoretical analysis: the discrepancy between the theoretical and experimental values of the degree of pressure multiplication in the working cylinder does not exceed 11%.

scholarly journals A FEA Method for Mathematical Calculation and Prediction Analysis Cross-sectional Ovalization of Tubes under Rotary Straightening

2021 ◽  
Vol 2083 (4) ◽  
pp. 042057
Author(s):  
Ziqian Zhang ◽  
Ying Zhong
Keyword(s):  
Process Parameters ◽  
Element Model ◽  
Simulation Method ◽  
Stress And Strain ◽  
Cross Sectional ◽  
Bending Deformation ◽  
Deformation Stage ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Flattening Process

Abstract The section flattening phenomenon (namely Bazier effect) will occur in the large bending deformation stage of thin-walled pipe in the continuous straightening process. The maximum section flattening amount and the residual section flattening amount are important process parameters, which are the basis for calculating the subsequent process parameters of the flattening circle, and directly determine the roundness of the final pipe and the product quality. However, it is hard to be obtained by the theoretical or experimental methods. Therefore, based on the structure and process parameters of the leveler, a finite element model was built to simulate the section flattening process. Then, ANSYS/LS-DYNA software was used to dynamically simulate the bending flattening phenomenon of thin-walled pipe in the continuous straightening process, and the stress and strain nephographic of the flattening deformation zone was obtained. By recording the position curve of the key nodes in the preventing process, the section flattening amount of the thin-walled pipe in the large bending deformation stage in the continuous straightening process was determined. The simulation results show that the dynamic simulation method can effectively predict the section flattening of thin-walled pipe in the process of continuous straightening.

An Elementary Theory of the Bourdon Gage

1946 ◽  
Vol 13 (3) ◽  
pp. A207-A210
Author(s):  
Alfred Wolf
Keyword(s):  
Wall Thickness ◽  
Maximum Stress ◽  
Transverse Section ◽  
Elementary Theory ◽  
Thin Walled ◽  
Longitudinal Extension

Abstract A theory of the Bourdon gage is presented based upon two elements of strain, namely, the bending of the walls in a transverse section through the gage tubing, and a longitudinal extension parallel to the axis of the tubing. Practical formulas are derived for the calculation of the sensitivity and the torque of the Bourdon gage. An estimate is made of the maximum stress. The sensitivity of a very thin-walled gage is shown to be proportional to the inverse first power of the wall thickness. Results of a few measurements show agreement with the theory.

Repair of Leaks in Thin Wall High Pressure Pipelines Using Composite Reinforcing Technologies

2020 ◽  
Author(s):  
Chris Alexander ◽  
Salem Talbi ◽  
Richard Kania ◽  
Jon Rickert
Keyword(s):  
High Pressure ◽  
Operating Conditions ◽  
Thin Wall ◽  
Nitrogen Gas ◽  
Composite Repair ◽  
Pressure Cycling ◽  
Thin Walled Pipe ◽  
Corrosion Defects ◽  
Thin Walled ◽  
Pipe Materials

Abstract A study was conducted to evaluate two composite repair technologies used to reinforce severe corrosion and thru-wall leaking defects in thin-walled pipe materials; conditions where the welding of conventional Type B steel sleeves cannot be conducted. This program involved the reinforcement of simulated 85% corrosion defects in 6.625-inch × 0.157-inch, Grade X52 pipe materials subjected to cyclic pressure and burst testing. The test matrix also included repaired pipe samples with thru-wall defects that were pressurized using nitrogen gas and buried for 90 days. The program was comprehensive in that it evaluated the following elements involving a total of 81 reinforced corrosion defects. • Corrosion features with a depth of 85% of the pipe’s nominal wall thickness in thin-walled pipe material (i.e., 0.157 inches, or 4 mm). • Thru-wall defects having a diameter of 0.125 inches (3 mm). • Repairs made with leaking defects having 100 psig (690 kPa) internal pressure. • Strain gage measurement made in non-leaking 85% corrosion defects; it should be noted that the remaining “15%” ligament was 0.024 inches (0.6 mm); to the author’s knowledge, no high-pressure testing has ever been conducted on such a thin remaining wall. • Long-term 90-day test that included pressurization with nitrogen gas, followed by relatively aggressive pressure cycling up to 80% SMYS followed by burst testing. This is the first comprehensive study conducted by a major transmission pipeline operator evaluating the performance of competing composite technologies used to reinforce severe corrosion features with thru-wall defects. The reinforcement of leaks has not been accepted by regulatory bodies such as the Canadian Energy Regulator (CER), or the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA). A goal of the current study is to validate composite repair technologies as a precursor to regulatory approval. The results of this study indicate that viable composite repair technologies exist with capabilities to reinforce leaks in pipelines that experience operating conditions typical for gas transmission systems (i.e., minimal pressure cycling).

Sign in / Sign up

Export Citation Format

Share Document