Effect of weld zone and corner with cold bending effect on wrinkling of rectangular welded tube in rotary draw bending

Hydroformed parts have higher dimensional accuracy, structural strength, and dimensional repeatability. The pre-bending process is an important process for the successful hydroforming in the case where the perimeter of the blank is nearly the same as that of final product. At initial pre-bending stage, the variations of wall thickness and cross-section have effects on the accuracy of final products and quality. Because of a relatively excellent productive velocity, geometric size precision and reliance of product qualities, rotary draw bending is widely used. This study shows the bendability such as cross-section ovality, springback ratio and thickness variation in the various conditions of materials.

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Numerical Research on High-Strength Rectangular Section Steel Tube in Rotary-Draw Bending

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.620.417 ◽

2014 ◽

Vol 620 ◽

pp. 417-423 ◽

Cited By ~ 2

Author(s):

Zhong Wen Xing ◽

Zhi Wei Xu ◽

Hong Liang Yang ◽

Cheng Xi Lei

Keyword(s):

High Strength ◽

Element Model ◽

Steel Tube ◽

Rotary Draw Bending ◽

Rectangular Section ◽

Control Variate ◽

Fillet Radius ◽

Bending Process ◽

Bending Radius ◽

Draw Bending

A finite element model of high-strength rectangular section steel tube in rotary-draw bending is established to study the stress and strain in the bending process. Based on control variate method, this paper analyzes the influence laws of three geometric parameters on rotary-draw bending. The results show that bending radius is the most important factor, forming property increases significantly with the increase of bending radius, the trends of cracking and wrinkling are all decreased. The thickness of wall has influence on the strain of inwall, thinner tube may cause crack and wrinkle. Fillet radius has no effect on ektexine, the strain of inwall decreases slightly with the increase of fillet radius.

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Effect of Different Welded Structures on Mechanical Properties of TA2 Tube-to-Tubesheet Joints

Journal of Pressure Vessel Technology ◽

10.1115/1.4026566 ◽

2014 ◽

Vol 136 (4) ◽

Cited By ~ 1

Author(s):

Xinlong Wei ◽

Yang Qian ◽

Junhui Wang ◽

Jianxin Zhou ◽

Xiang Ling

Keyword(s):

Applied Load ◽

Low Cycle Fatigue ◽

Weld Zone ◽

Steel Tube ◽

Fatigue Tests ◽

Cycle Fatigue ◽

Welded Structures ◽

Pull Out ◽

Weld Toe ◽

Welded Tube

Four types of TA2 welded tube-to-tubesheet joints prepared by manual tungsten arc argon-shielded welding technique are studied in this paper. The pull-out tests and low cycle fatigue tests were performed to optimize welded structures of tube and tubesheet. The results show that fractures of welded TA2 tube and tubesheet samples occur at weld zone of TA2 steel tube for the pull-out tests and low cycle fatigue tests. The extension-tubesheet welded joints have the maximum pull-out forces and the best fatigue resistance, and the internal-bore welded joint with 45 deg bevel occupies second place. Fractures are both initiated from weld toe of the outside of tube for the pull-out tests and low cycle fatigue tests. Crack propagates along the direction of 45 deg for the pull-out test. However, crack propagates perpendicularly to the direction of the applied load for low cycle fatigue test, and then fractures immediately parallel to the direction of the applied load. Fatigue striations with a spacing of about 10 μm can be observed on the fatigue crack propagation zone. However, hemispheroidal dimples exist on instant rupture zone.

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