Numerical Simulation of Tube-Bending Process with Internal Pressure for Titanium Alloy Tube

2005 ◽  
Vol 475-479 ◽  
pp. 3279-3282
Author(s):  
Xia Huang ◽  
Yuan Song Zeng ◽  
Zhi Qiang Li ◽  
Xin Hua Zhang
Keyword(s):  
Titanium Alloy ◽  
Internal Pressure ◽  
Forming Process ◽  
Cold Bending ◽  
Bending Process ◽  
Thickness Prediction ◽  
Bending Radius ◽  
Experimental Values ◽  
Titanium Alloy Tube ◽  
Good Agreement

In this paper, a new cold bending process is presented to form the titanium alloy tubular part with small relative bend radius, that is, its centerline bending radius is less than 2 times the outside diameter of the tube. FEM is applied to simulate the forming process, and at the same time the results, such as the distribution of the stress and the wall thickness, prediction of defects area, the effects of the internal pressure and friction condition on the tube deformation, are also analyzed. Finally, experimental research was preformed. It is found that the numerical results are in good agreement with the experimental values.

Research on the Die Fittingness and Springback of Large Diameter Thin-Walled CT20 Titanium Alloy Tube NC Bending

2012 ◽  
Vol 472-475 ◽  
pp. 997-1002 ◽  
Author(s):  
Jian Guang Wang ◽  
Mei Zhan ◽  
Tao Huang ◽  
He Yang
Keyword(s):  
Titanium Alloy ◽  
Compressive Stress ◽  
Large Diameter ◽  
Alloy Tube ◽  
Bending Process ◽  
Bending Radius ◽  
Thin Walled ◽  
Titanium Alloy Tube ◽  
Assembly Precision ◽  
Nc Bending

The significant die unfittingness and springback, occuring during the numerically controlled (NC) bending process of large diameter thin-walled CT20 titanium alloy tube, has an obvious influence on the shape and the geometrical precision of the bent tube, furthermore on the assembly precision and the sealing capability. The changing rules of die fittingness and springback of large diameter thin-walled CT20 titanium alloy tube under different bending parameters were investigated and the mechanism was analysed using finite element method (FEM) in this paper. The result shows that the springback of large diameter thin-walled CT20 titanium alloy tube is more significant than that of aluminum alloy and stainless steel tubes with the same specification. The die fittingness has a connection with the tangent compressive stress on the intrados of the tube before springback, the larger the tangent compressive stress, the worse is the die fittingness.The results may provide a significant guide to the control of bending radius and bending angle for large diameter thin-walled titanium alloy tube NC bending.

Comparison of Bending of Automotive Steels in Roll Forming and in a V-Die

2012 ◽  
Vol 504-506 ◽  
pp. 797-802 ◽  
Author(s):  
Matthias Weiss ◽  
Jascha Marnette ◽  
Preston Wolfram ◽  
Jon Larrañaga ◽  
Peter D. Hodgson
Keyword(s):  
Analytical Equation ◽  
Roll Forming ◽  
Cold Roll Forming ◽  
Forming Process ◽  
Cold Roll ◽  
Bending Process ◽  
Roll Forming Process ◽  
Springback Angle ◽  
Die Forming ◽  
Good Agreement

Bending in a V-die has been used to indicate the outcome of bending in cold roll forming, although little direct correlation has been performed. In this work direct comparison of the springback in both processes was performed using six samples of automotive steels in a conventional roll forming line where the transverse springback is measured. A bend of similar radius was formed in a V-die and the springback determined. In general, the springback in V-die forming was greater than in roll forming, in some cases by a factor of 2. The theoretical springback angle was determined for all steels using a simple and approximate analytical equation and compared to the experimental roll forming and bending results. While for the roll forming process good agreement was achieved the theoretical values significantly underestimated springback in the V-bending process.

Relationships between Spring-Back and Microstructure of Ti-15V-3Cr-3Sn-3Al Titanium Alloy Sheet during Bending Process

2013 ◽  
Vol 747-748 ◽  
pp. 839-843
Author(s):  
Lin Lin Li ◽  
Guo Qing Wu ◽  
Chang Xu Liu ◽  
Ai Xue Sha
Keyword(s):  
Titanium Alloy ◽  
Linear Growth ◽  
Alloy Sheet ◽  
Micro Hardness ◽  
Spring Back ◽  
Bending Deformation ◽  
Bending Process ◽  
Bending Radius ◽  
Back Angle ◽  
Deformation Area

Evolutions of microstructure, micro-hardness in the central deformation area and spring-back, were studied in different bending conditions of Ti-15V-3Cr-3Sn-3Al titanium alloy sheet. The results show that, with the increase of bending deformation, i.e. increase of bending angle or decrease of bending radius, the grain area, the grain feret diameter ratio and micro-hardness in the central deformation area all show nearly linear growth trends. The spring-back angle has no clearly correlation with the degree of bending deformation. While the spring-back rate correlates positively with the length of deformation-affected zone, which can reflect the characteristics of bending deformation more intuitively than that of spring-back angle.

Research on the Springback of Square TA18 Titanium Alloy Tube on the Numerical Simulation

2019 ◽  
Vol 944 ◽  
pp. 753-760 ◽  
Author(s):  
Cong Liu ◽  
Xiao Dong Yan ◽  
Yin Yang ◽  
Wei Ye
Keyword(s):  
Numerical Simulation ◽  
Titanium Alloy ◽  
Process Parameters ◽  
Three Dimensional ◽  
Outer Wall ◽  
Element Model ◽  
Bending Angle ◽  
Alloy Tube ◽  
Bending Radius ◽  
Titanium Alloy Tube

This paper focuses on how bending and springback process of the titanium tubes with different bending radius and bending angle affect the springback rate after unloading and analyses tube distributions and variations of stress and strain by establishing a three-dimensional elastic-plastic finite element model of square TA18 titanium alloy tube based on ABAQUS/explicit and ABAQUS/standard. It is shown that under the same process parameters, the sprignback rate obtained by numerical simulation is in good agreement with that measured in the experiments. The springback rate after unloading increases with the increase of the bending radius linearly, and it increases nonlinearly with the decrease of bending angle. The distribution of the tube-roundness and the relationship between its roundness and springback rate under different process parameters could be obtained by comparing the variation of the absolute value of its outer wall unit at the maximum principal strain before and after unloading.

Kinematics-Based Determination of the Rolling Region in Roll Bending for Smoothly Curved Plates

2000 ◽  
Vol 123 (2) ◽  
pp. 284-290 ◽  
Author(s):  
Jong Gye Shin ◽  
Joon Tae Park ◽  
Hyunjune Yim
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Systematic Approach ◽  
Linear Regression Analysis ◽  
Forming Process ◽  
Roll Bending ◽  
Bending Process ◽  
Curvature Distribution ◽  
Good Agreement

This paper proposes and develops a kinematics-based, systematic approach to determine the region of a plate to be rolled, in order to fabricate smoothly curved plates. The approach includes a kinematic analysis to calculate the plate’s curvature distribution, and, in addition, a linear regression analysis to determine the initial and final locations of the roller during the roll bending process. Three artificial cases and two real cases have been studied, and the results are in good agreement with field practices. This approach will play an important role in the automation and optimization of the plate forming process.

scholarly journals The Effect of Spiral Cold-Bending Manufacturing Process on Pipeline Mechanical Behavior

2016 ◽  
Author(s):  
Giannoula Chatzopoulou ◽  
Gregory C. Sarvanis ◽  
Chrysanthi I. Papadaki ◽  
Spyros A. Karamanos
Keyword(s):  
Internal Pressure ◽  
Manufacturing Process ◽  
Numerical Models ◽  
Large Diameter ◽  
External Pressure ◽  
Forming Process ◽  
Cold Forming ◽  
Cold Bending ◽  
Offshore Pipeline ◽  
Bending Capacity

Large-diameter spiral-welded pipes are employed in demanding hydrocarbon pipeline applications, which require an efficient strain-based design framework. In the course of a large European project, numerical simulations on spiral-welded pipes are conducted to examine their bending deformation capacity in the presence of internal pressure referring to geohazard actions, as well as their capacity under external pressure for offshore applications in moderate deep water. Numerical models that simulate the manufacturing process (decoiling and spiral cold bending) are employed. Subsequently, the residual stresses due to cold bending are used to examine the capacity of pipe under external pressure and internally-pressurized bending. A parametric analysis is conducted to examine the effect of spiral cold forming process on the structural behavior of spiral welded pipes and the effect of internal pressure on bending capacity. The results from the present study support the argument that spiral-welded pipes can be used in demanding onshore and offshore pipeline applications.

Forming of Stringer Sheets with Solid Tools

2016 ◽  
Vol 1140 ◽  
pp. 3-10 ◽  
Author(s):  
Stefan Köhler ◽  
Peter Groche ◽  
Alexander Baron ◽  
Maximilian Schuchard
Keyword(s):  
Failure Modes ◽  
Sheet Thickness ◽  
Experimental Investigations ◽  
Sheet Metal Parts ◽  
Flat Sheet ◽  
Bending Process ◽  
Analytical Estimation ◽  
Bending Radius ◽  
The Common ◽  
Good Agreement

Stringer sheets are bifurcated parts that possess, compared to flat sheet metal parts, a higher stiffness due to their higher geometrical moment of inertia. Currently, the common way of forming spatially curved stringer sheets is hydroforming. This article shows the feasibility of forming stringer sheets by using solid tools with short process times, which is more relevant for the industrial application. A die-bending process with a slot in the punch for the stringer is investigated. Since buckling of the stringer is one of the occurring failure modes, depending on the stringer height, an analytical estimation of the critical stringer height is carried out while considering the bending angle, bending radius and sheet thickness. The subsequent numerical and experimental investigations show a good agreement with the analytical estimation. Finally, a stiffness test is carried out with stringer sheets of different stringer heights. The result of this test underlines the motivation of forming buckling-free stringer sheets with stringers as high as possible. The normalized stiffness increases with rising stringer height until buckling occurs. At this point the stiffness values begin to fall with growing stringer height.

Experimental and Analytical Study of Cold Bending Process for Pipelines

2003 ◽  
Vol 125 (2) ◽  
pp. 153-157 ◽  
Author(s):  
Naoki Fukuda ◽  
Hiroshi Yatabe ◽  
Shinobu Kawaguchi ◽  
Takahito Watanabe ◽  
Tomoki Masuda
Keyword(s):  
Analytical Study ◽  
Longitudinal Direction ◽  
Tensile Tests ◽  
Full Scale ◽  
Obvious Effect ◽  
Cold Bending ◽  
Bending Process ◽  
Strain Relationship ◽  
Cold Bends ◽  
Good Agreement

The behavior during the cold bending of pipelines was experimentally and analytically investigated. Full-scale cold bending experiments were performed on API X60 and X80 grade line pipes. Finite element (FE) analyses simulated the cold bending process by considering the contact interactions between a pipe and the components of the bending machine. The results of the simulation were in good agreement with the full-scale experiments. The stress-strain relationship and yield to tensile ratio (Y/T) had no obvious effect on the strain distribution after cold bending. The tensile tests quantitatively evaluated the decrease in the yield stress along the longitudinal direction on the cold bends due to the Bauschinger effect.

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