scholarly journals Stress analysis of double-walled pipes undergone mechanical drawing process

2022 ◽  
Author(s):  
RuoGu Zhang ◽  
Yu Wang ◽  
Yinbo Zhu ◽  
JiDong Jin ◽  
HengAn Wu ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Mechanical Model ◽  
Drawing Process ◽  
Test Procedures ◽  
Industrial Manufacturing ◽  
Theoretical Support ◽  
State Evolution ◽  
Metal Pipes ◽  
Thin Walled ◽  
The Ideal

AbstractDouble-walled metal pipes are important components for heat exchange and liquid transportation. They can be manufactured by mechanical drawing of two concentric pipes. In this work, a mechanical model is developed to analyze the stress state evolution during the manufacturing process, and the criterion for forming the double-walled pipe was given under the ideal elastoplastic and thick-walled assumptions. The model also encompasses the results deduced under the thin-walled assumption. Numerical simulations confirmed that the accuracy of the analytical model was within 5%. The application on actual steel materials with various parameters varied, including the wall thickness and initial gap, was analyzed. This work can provide theoretical support to industrial manufacturing procedures and help to reduce costs by eliminating required test procedures.

scholarly journals Stress analysis of double-walled pipes undergone mechanical drawing process

2021 ◽  
Author(s):  
Ruogu Zhang ◽  
Yu Wang ◽  
Yinbo Zhu ◽  
JiDong Jin ◽  
HengAn Wu ◽  
...  
Keyword(s):  
Mechanical Model ◽  
Thick Wall ◽  
Thin Wall ◽  
Drawing Process ◽  
Test Procedures ◽  
Industrial Manufacturing ◽  
Theoretical Support ◽  
State Evolution ◽  
Metal Pipes ◽  
The Ideal

Abstract Double-walled metal pipes are important components for heat exchange and liquid transportation. They can be manufactured by mechanical drawing of two concentric pipes. In this work, a mechanical model is developed to analyze the stress state evolution during the manufacturing process, and the criterion for forming the double-walled pipe was given under the ideal elastoplastic and thick-wall assumptions. The model also encompasses the results deduced under the thin-wall assumption. Numerical simulations confirmed that the accuracy of the analytical model was within 5%. The application on actual steel materials with various parameters varied, including the wall thickness and initial gap, was analyzed. This work can provide theoretical support to industrial manufacturing procedures and help to reduce costs by eliminating required test procedures.

Desaturation of exhaled air in camels

1981 ◽  
Vol 211 (1184) ◽  
pp. 305-319 ◽  
Keyword(s):  
Drinking Water ◽  
Heat Exchange ◽  
Body Temperature ◽  
Water Vapour ◽  
Mechanical Model ◽  
Ambient Air ◽  
Body Core Temperature ◽  
Hygroscopic Properties ◽  
Exhaled Air ◽  
Body Core

We have found that camels can reduce the water loss due to evaporation from the respiratory tract in two ways: (1) by decreasing the temperature of the exhaled air and (2) by removal of water vapour from this air, resulting in the exhalation of air at less than 100% relative humidity (r. h.). Camels were kept under desert conditions and deprived of drinking water. In the daytime the exhaled air was at or near body core temperature, while in the cooler night exhaled air was at or near ambient air temperature. In the daytime the exhaled air was fully saturated, but at night its humidity might fall to approximately 75% r. h. The combination of cooling and desaturation can provide a saving of water of 60% relative to exhalation of saturated air at body temperature. The mechanism responsible for cooling of the exhaled air is a simple heat exchange between the respiratory air and the surfaces of the nasal passageways. On inhalation these surfaces are cooled by the air passing over them, and on exhalation heat from the exhaled air is given off to these cooler surfaces. The mechanism responsible for desaturation of the air appears to depend on the hygroscopic properties of the nasal surfaces when the camel is dehydrated. The surfaces give off water vapour during inhalation and take up water from the respiratory air during exhalation. We have used a simple mechanical model to demonstrate the effectiveness of this mechanism.

scholarly journals Tube Drawing Process with Diameter Expansion for Effectively Reducing Thickness

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1642
Author(s):  
Shohei Kajikawa ◽  
Hikaru Kawaguchi ◽  
Takashi Kuboki ◽  
Isamu Akasaka ◽  
Yuzo Terashita ◽  
...  
Keyword(s):  
Axial Load ◽  
Fem Analysis ◽  
Axial Direction ◽  
Drawing Process ◽  
Maximum Expansion ◽  
Tube Drawing ◽  
Thin Walled Tube ◽  
Forming Characteristics ◽  
Thin Walled ◽  
Drawing Method

The present paper describes a tube drawing method with diameter expansion, which is herein referred to as “expansion drawing”, for effectively producing thin-walled tube. In the proposed method, the tube end is flared by pushing a plug into the tube, and the tube is then expanded by drawing the plug in the axial direction while the flared end is chucked. The forming characteristics and effectiveness of the proposed method were investigated through a series of finite element method (FEM) analyses and experiments. As a result of FEM analysis, the expansion drawing effectively reduced the tube thickness with a smaller axial load when compared with the conventional method. According to the experimental results, the thin-walled tube was produced successfully by the expansion drawing. Maximum thickness reduction ratios for a carbon steel (STKM13C) and an aluminum alloy (AA1070) were 0.15 and 0.29 when the maximum expansion ratios were 0.23 and 0.31, respectively. The above results suggest that the proposed expansion drawing method is effective for producing thin-walled tubes.

Controlling Wrinkling and Flatness during the Processing of the Bend Section of a Pipe by Applying Vibration to the Mandrel

2015 ◽  
Vol 656-657 ◽  
pp. 600-603 ◽  
Author(s):  
Xia Zhu ◽  
Narumi Wada ◽  
Keiji Ogi ◽  
Hiroshi Kurosu ◽  
Manabu Takahashi ◽  
...  
Keyword(s):  
Nonlinear Finite Element ◽  
Outer Diameter ◽  
Bend Section ◽  
Finite Element Software ◽  
Bending Process ◽  
Bending Radius ◽  
Metal Pipes ◽  
Thin Walled ◽  
Pipe Processing ◽  
Distribution Of Stresses

Metal pipes have a long history as fluid conduits, and are commonly joined with components such as elbows to form bent transport paths. However, with the increasing demands for economy and energy saving, pipes with reduced joints and thinner walls are desired. The number of joints can be reduced by a drawing and bending process that forms a bend section at any position in the pipe. However, this approach incurs problems such as wrinkling and flattening, especially under conditions of large bending angle, decreased bending radius, and thin pipe walls. In this research, applying vibrations to the mandrel was trialed as an approach for controlling the wrinkle depth and flattening. First, processing experiments were performed on thin walled pipes (wall thickness = 0.5 mm; outer diameter = 14 mm). The change of flattening and the number and depths of wrinkles were investigated in the presence and absence of vibrations. Next, simulations were performed using the commercial nonlinear finite element software. Through these simulations, the flatness and appearance of wrinkles were analyzed by modeling the behavior and distribution of stresses and strains in the processing process. The application of vibration to the mandrel appears to be a promising approach for controlling the wrinkling and flattening problems during pipe processing.

scholarly journals MATHEMATICAL MODELING OF HEAT TRANSFER IN A HORIZONTAL HEAT EXCHANGE PIPE

2020 ◽  
Vol 2020 (1) ◽  
pp. 57-60
Author(s):  
Aleksey Bal'chugov ◽  
Mihail Vazhenin ◽  
Borislav Kustov
Keyword(s):  
Mathematical Modeling ◽  
Heat Transfer ◽  
Heat Exchange ◽  
Transfer Process ◽  
Heat Transfer Process ◽  
Atmospheric Air ◽  
Ideal Displacement ◽  
Displacement Model ◽  
The Ideal

It has been experimentally established that the ideal displacement model adequately describes the heat transfer process in a horizontal heat exchange pipe cooled by atmospheric air

New Type Geo-Mechanical Similar Material Experiments Research and Its Application

2006 ◽  
Vol 326-328 ◽  
pp. 1801-1804
Author(s):  
Shu Cai Li ◽  
Han Peng Wang ◽  
Qiang Yong Zhang ◽  
Yong Li
Keyword(s):  
Rock Mass ◽  
Model Test ◽  
Mechanical Model ◽  
Iron Ore ◽  
Material Research ◽  
Similar Material ◽  
Mechanics Model ◽  
New Type ◽  
Stable Performance ◽  
The Ideal

It is very important to choose a similar material which simulates rock mass correctly in geo-mechanics model test. In this paper, we introduce similar material research status and analyze the principle of selecting and compounding. According to the experiences of similar material research, we develop a new similar material (we call it iron barites sand cementation material, abbreviate IBSCM) through hundreds of compounding experiment. This similar material is made up of iron ore powder, barites powder, sand, rosin, alcohol and gypsum powder. Iron ore powder, barites powder and sand are main materials, the solution of rosin and alcohol is glue, and gypsum powder is regulator. Specimen mechanics tests show that different rock mass can be simulated by the model materials with different materials compounding. The new similar material is easy to buy and its price is cheap, and it has some advantages, such as high density, stable performance, easy dryness, and easy cutting. The new similar material can simulate a lot of rock mass, so it is an ideal similar material. At last, we apply this new type similar material to tunnel geo-mechanical model test and gain the ideal result.

Study on the Stress-Strain Distribution Rule of the Cylindrical Part Deep Drawing with Prefabricate-Holes

2011 ◽  
Vol 317-319 ◽  
pp. 231-235
Author(s):  
Li Guang Tan ◽  
Xiao Ting Xiao ◽  
Hua Dian Wen ◽  
Qiao Yu Chen
Keyword(s):  
Deep Drawing ◽  
Mechanical Model ◽  
Strain Distribution ◽  
Cylindrical Part ◽  
Drawing Process ◽  
Analysis Software ◽  
Stress Strain ◽  
Deep Drawing Process ◽  
Distribution Rule

With the flange deformation in the deep drawing process of prefabricate-holes part, makes the area around the prefabricate-hole as the research object, the mechanical model was established, using analysis software of Dynaform to simulate and analyze, explore the stress-strain distribution rule of the deep drawing process.

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