Calculation Model of Punch Force during Tube Extrusion

2011 ◽  
Vol 704-705 ◽  
pp. 273-276
Author(s):  
Zhong Tang Wang ◽  
Guang Xia Qi ◽  
Fang Wang ◽  
Shi Hong Zhang
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Calculation Model ◽  
Extrusion Force ◽  
Calculation Formula ◽  
Slab Method ◽  
Punch Force ◽  
Tube Extrusion ◽  
Relative Errors ◽  
Theoretical Results

] Theoretical calculation formula of punch force during tube extrusion has been proposed by means of slab method. On the basis of theoretical and experimental study, it is found that theoretical results of extrusion force given by the calculating formula approached to that of the experiment, and the relative errors are less than 20％. It is also found that the extrusion force is closely related to deformation temperature, lubricant and the ratio of extrusion. The calculating formula of extrusion force is given by considering the factors which are the conical angle of die, and the friction coefficient between the deformation zone and the extrusion container, and the friction coefficient between the undeformed zone and the mandrel. Key Words: Tube, Extrusion, Force, Physical model

An Investigation of Die Wear Behavior During Aluminum Alloy 7075 Tube Extrusion

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Cunsheng Zhang ◽  
Guoqun Zhao ◽  
Tingting Li ◽  
Yanjin Guan ◽  
Hao Chen ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Wear Behavior ◽  
Extrusion Force ◽  
Wear Depth ◽  
Process Variables ◽  
Die Wear ◽  
Tube Extrusion ◽  
Ram Speed ◽  
Aluminum Alloy 7075

During hot extrusion process, die wear shortens markedly the service life of extrusion dies under the high-pressure, high-temperature conditions. In this paper, based on modified Archard's wear model, a user-defined subroutine for calculating die wear depth was developed and implanted into DEFORM-3D. On the basis of the numerical model, the die wear behavior during aluminum alloy 7075 tube extrusion has been investigated. The numerical results show that process variables have multiple effects on die wear behavior. With the increasing ram speed, wear depth of die bearing rises and then tends to decline gradually. From the ram speed of 15 mm/s, die wear depth begins to increase again. Wear depth rises suddenly with the increase of friction coefficient, then gradually reduces. When friction coefficient is greater than 0.8, wear depth tends to be a constant. A maximum wear depth occurs at 430 °C of billet temperature, and a minimum wear depth occurs at certain die temperature in the range of 400–425 °C. In addition, the required extrusion force has strong dependence on process variables. The extrusion force rises clearly with the increase of ram speed and friction coefficient and with the decrease of initial temperatures of billet and die.

Experimental Study on the Failure Criterion for Brittle Materials in Compression

2011 ◽  
Vol 320 ◽  
pp. 259-262
Author(s):  
Xu Ran ◽  
Zhe Ming Zhu ◽  
Hao Tang
Keyword(s):  
Thin Film ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fracture Mechanics ◽  
Failure Criterion ◽  
Brittle Materials ◽  
Experimental Results ◽  
Experiment Study ◽  
Confining Stress ◽  
Theoretical Results

The mechanical behavior of multi-cracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, based on the previous theoretical results of the failure criterion for brittle materials under compression, experiment study is implemented. The specimens are square plates and are made of cement, sand and water, and the cracks are made by using a very thin film (0.1 mm). The relations of material compressive strength versus crack spacing and the lateral confining stress are obtained from experimental results. The experimental results agree well with the failure criterion for brittle materials under compression, which indicates that the criterion is effective and applicable.

scholarly journals Experimental study of the contact line friction coefficient

2020 ◽  
Vol 1677 ◽  
pp. 012156
Author(s):  
N Sibiryakov ◽  
W Zheng ◽  
O Kabov ◽  
B Bai
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Contact Line ◽  
Contact Line Friction

Sustained Casing Pressure Calculation of A Annulus Induced by Downhole Operation Load

2012 ◽  
Vol 430-432 ◽  
pp. 2067-2070
Author(s):  
Zhang Zhi ◽  
Tai Ping Xiao ◽  
Zheng Mao Chen ◽  
Tai He Shi
Keyword(s):  
Internal Pressure ◽  
Safety Evaluation ◽  
Calculation Model ◽  
Extrusion Force ◽  
External Diameter ◽  
Gas Well ◽  
Seal Failure ◽  
Theoretical Support ◽  
Sustained Casing Pressure ◽  
Casing Pressure

Currently the annulus pressure of gas well becomes more common, so the safe production of several wells has been seriously affected. The annulus pressure mechanism is relatively complex, and it can be approximately classified into annulus pressure induced by temperature effect, by ballooning effect and by leakage or seal failure etc. The article mainly focuses on the annulus pressure mechanism induced by ballooning effect and the corresponding calculation model. For the tubing column with two ends fixed and closed, when tubing internal pressure is larger than the external extrusion force, the external diameter of the tubing column balloons (i.e. ballooning effect). It reduces the annular volume between the tubing and the casing, and consequentially induces annulus pressure. Based on the fundamental theory of elastic-plastic mechanics, the tubing column is simplified into the thin walled cylinder so as to deduce the relation models between the internal pressure and its swell capacity and A annulus pressure value, which provide theoretical support for safety evaluation on annulus pressure and the next treatment program.

Experimental Study of a Variable Pressure Damper on Automotive Valve Motion

1996 ◽  
Author(s):  
Jin-Jang Liou ◽  
Grodrue Huang ◽  
Wensyang Hsu
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Friction Force ◽  
High Speed ◽  
Experimental Results ◽  
Variable Pressure ◽  
Friction Forces ◽  
Valve Spring ◽  
Valve Motion

Abstract A variable pressure damper (VPD) is used here to adjusted the friction force on the valve spring to investigate the relation between the friction force and the valve bouncing phenomenon. The friction force on the valve spring is found experimentally, and the corresponding friction coefficient is also determined. Dynamic valve displacements at different speeds with different friction forces are calibrated. Bouncing and floating of the valve are observed when the camshaft reaches high speed. From the measured valve displacement, the VPD is shown to have significant improvement in reducing valve bouncing distance and eliminating floating. However, experimental results indicate that the valve bouncing can not be eliminated completely when the camshaft speed is at 2985 rpm.

Calculation of Punch Force and Maximum Pressure for Tube Extrusion

2000 ◽  
Author(s):  
S.-H. Zhang ◽  
Y.-L. Shang
Keyword(s):  
Upper Bound ◽  
Physical Modeling ◽  
Steel Tube ◽  
Experimental Results ◽  
Maximum Pressure ◽  
Punch Force ◽  
Tube Extrusion ◽  
Tooling System ◽  
Very High ◽  
Good Agreement

Abstract Punch force and maximum pressure for tube extrusion can be predicted with an upper bound theory-based program POLSK. Experiments of steel tube extrusion and wax physical modeling were performed. The punch force and the maximum pressure values were obtained. Comparisons were made among the experimental results, physical modeling results and upper bound predictions. It was found that a medium extrusion coefficient causes the lowest pressure on the tooling system, very low and very high extrusion coefficients can both cause very high pressure. It is proved that the upper bound predictions are in good agreement with the experimental results and the upper bound program is suitable for use of steel tube extrusion design.

Experimental study on friction performance of damaged interface in steel-concrete composite beam connected by high-strength bolt

2020 ◽  
pp. 136943322094720
Author(s):  
Ying Xing ◽  
Ya-ning Xu ◽  
Qi Guo ◽  
Jin-feng Jiao ◽  
Qing-wei Chen
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Composite Beam ◽  
Structural Characteristics ◽  
Concrete Strength ◽  
Steel Structures ◽  
High Strength ◽  
Steel Strength ◽  
Bare Steel ◽  
Friction Performance

Although traditional steel-concrete composite beam has excellent structural characteristics, it cannot meet the requirement of quick disassembly and repair in the bridge. This article presents an experimental study on friction performance of damaged steel-concrete interface in recoverable composite beam connected by high-strength frictional bolts. A total of 21 specific split tests were carried out using different concrete strength, steel strength, and surface treatment of steel. The experimental results showed that the demountable high-strength frictional bolt used in composite beam has similar performance as in the bare steel structures. The initial friction coefficient and slip stiffness were measured to be 0.34–0.47 and 52.3–116.1 kN/mm, respectively. Friction performance of damaged interface was obtained, proving that friction coefficient and slip stiffness will not decrease after the first slip damage. It is also confirmed that shot blasted steel and concrete with higher strength were more suitable in the demountable composite beam.

An Experimental Study of Torsional Vibration Absorbers

2001 ◽  
Author(s):  
Alan G. Haddow ◽  
Steven W. Shaw
Keyword(s):  
Experimental Study ◽  
Dynamic Behavior ◽  
Systematic Study ◽  
Torsional Vibration ◽  
Theoretical Background ◽  
Controlled Environment ◽  
Vibration Absorbers ◽  
Test Apparatus ◽  
First Time ◽  
Theoretical Results

Abstract This paper presents results from tests completed on a rotor system fitted with pendulum-type torsional vibration absorbers. A review of the associated theoretical background is also given and the experimental and theoretical results are compared and contrasted. An overview of the test apparatus is provided and its unique features are discussed. To the best knowledge of the authors, this is the first time that a systematic study of the dynamic behavior of torsional vibration absorbers has been undertaken in a controlled environment.

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