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

2014 ◽  
Vol 620 ◽  
pp. 417-423 ◽  
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.

Numerical and Experimental Research on Warm Tension-Rotation Bending of Extruded AZ31 Profile

2011 ◽  
Author(s):  
Shi-hong Zhang ◽  
Han Xiao ◽  
Jin-song Liu ◽  
Ming Cheng
Keyword(s):  
Main Parameter ◽  
Geometric Dimension ◽  
Element Model ◽  
Bending Test ◽  
Test Machine ◽  
Rotary Draw Bending ◽  
Bending Process ◽  
Forming Temperature ◽  
Dimensional Variation ◽  
Draw Bending

Magnesium alloy profiles have attracted more and more attention in automobile and aerospace industries. The rotary draw bending process is suitable to form profiles. A bending test machine is developed to conduct AZ31 profile bending experiment. A 3D elastic-plastic thermo-mechanical coupled finite element model is established and validated by experiment. The effects of process parameters on the geometric dimension of the profile were analyzed by using experimental and numerical methods. The results indicate that the pretension amount is the main parameter which influences the geometric dimension of the bent profile, then the forming temperature, following the bending angle. The dimensional variation of the middle-rib is relatively little, and the dimensional variations of the inside and the outside of the bent profile are large.

Side Wrinkling Characteristics in Rotary-Draw Bending Process of Thin-Walled Rectangular 3A21 Tube

2011 ◽  
Vol 697-698 ◽  
pp. 356-360
Author(s):  
Gang Yao Zhao ◽  
Yu Li Liu ◽  
Shan Tian ◽  
He Yang
Keyword(s):  
Wave Height ◽  
Three Dimensional ◽  
Element Model ◽  
Rotary Draw Bending ◽  
Bending Process ◽  
Dimensional Finite Element ◽  
Thin Walled ◽  
Draw Bending ◽  
Three Dimensional Finite Element ◽  
Aluminum Alloy Tube

Side wrinkling may be produced during rotary-draw bending process of thin-walled rectangular 3A21 aluminum alloy tube if the process parameters are inappropriate. To study the side wrinkling behavior, a three-dimensional finite-element model of the process was developed based on ABAQUS/Explicit code and its reliability was validated by experiment. Then, the side wrinkling characteristics of the tube were investigated. The results show that the side wrinkling wave height in the inner edge of the tube is smaller than that in the out edge of the tube, and the side wrinkling wave height in the neutral layer of the tube is minimal. With the bending process, the side wrinkling wave goes through producing, developing and stabilizing three stages in turn. After bending angle reached 30°, the side wrinkling wave height keeps almost unchanged. Furthermore, the number of the half side wrinkling wave increases evenly.

Experimental and numerical investigation of wrinkling and tube ovality in the rotary draw bending process

2019 ◽  
Vol 233 (16) ◽  
pp. 5568-5584 ◽  
Author(s):  
R Safdarian
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Tests ◽  
Steel Tube ◽  
Numerical Results ◽  
The Finite Element Method ◽  
Rotary Draw Bending ◽  
Bending Process ◽  
Draw Bending ◽  
Element Method

The tube wrinkling, ovality, and fracture are the main defects in the rotary draw bending process, which happen by incorrect selection of process parameters. In the present study, the wrinkling, fracture, and ovality of BS 3059 steel tube in the rotary draw bending were investigated using the experimental tests and the finite element method. The numerical results were verified using the experimental tests for tube ovality prediction. The tube fracture was predicted using the Gurson–Tvergaard–Needleman damage model in the rotary draw bending numerical simulations. The design of experiment based on the response surface method and the finite element method was used to investigate the effects of rotary draw bending parameters such as boosting velocity of pressure die, mandrel position, number of balls, and pressure of pressure die on the wrinkling, fracture, and tube ovality. The experimental and numerical results indicated that the mandrel position was one of the main parameters, which influence the tube ovality. The tube ovality and wrinkling increased with the increase in the mandrel position.

Variation of elastic modulus of high strength 21-6-9 tube and its influences on forming quality in numerical control rotary draw bending

2021 ◽  
pp. 095440622199069
Author(s):  
Jun Fang ◽  
Fang Ouyang ◽  
Shiqiang Lu ◽  
Kelu Wang ◽  
Xuguang Min ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Plastic Strain ◽  
High Strength ◽  
Steel Tube ◽  
Numerical Control ◽  
Repeated Loading ◽  
Stainless Steel Tube ◽  
Rotary Draw Bending ◽  
Forming Quality ◽  
Draw Bending

Elastic modulus is one of the most crucial mechanical property parameters that affects the plastic forming quality of bent parts, especially for springback. Elastic modulus practically varies with plastic deformation, and its precise description is necessary to enhance simulation precision for tube bending and gain steady, high-precision bent components by actual bending. Using repeated loading-unloading tensile tests (RLUTTs), the variation of elastic modulus of high strength 21-6-9 stainless steel tube (21-6-9-HS tube) in terms of plastic strain has been obtained, which its decreases rapidly at the beginning, then decreases tardily and tends to be stable in the end with increasing the plastic strain. The variation can be expressed as a first order exponential decay function. By embedding the variation of elastic modulus with the plastic strain into ABAQUS software to simulate numerical control (NC) rotary draw bending of the 21-6-9-HS tube, the prediction precision for the springback angle, springback radius, maximum cross section distortion ratio and maximum wall thinning ratio can be improved by 11.98%, 7.62%, 35.53% and 11.55%, respectively.

Characteristics of Rotary Draw-Bent Tubes for the Hydroforming

2011 ◽  
Vol 213 ◽  
pp. 320-324
Author(s):  
Byeong Don Joo ◽  
Jeong Hwan Jang ◽  
Hyun Jong Lee ◽  
Young Hoon Moon
Keyword(s):  
Cross Section ◽  
Structural Strength ◽  
Dimensional Accuracy ◽  
Thickness Variation ◽  
Important Process ◽  
Rotary Draw Bending ◽  
Higher Dimensional ◽  
Bending Process ◽  
Geometric Size ◽  
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.

Influence of Lubricants on Advanced High Strength Steel Tubes in Bending Process

2009 ◽  
Author(s):  
Ramakrishna Koganti ◽  
Sergio Angotti ◽  
Isadora van Riemsdijk ◽  
Robert C. Nelson ◽  
Jill Smith
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Steel Tube ◽  
Application Site ◽  
Structural Components ◽  
Advanced High Strength Steel ◽  
Steel Tubes ◽  
Automotive Body ◽  
Bending Process ◽  
Lubricant Performance

To reach safety, emissions, and cost objectives, manufacturers of automotive body structural components shape thin gauge, high strength steel tube using a series of manufacturing steps that often include bending, preforming and hydroforming. Challenging grades and bend severity require a sensitive optimization of the tubular bending process. Lubricants play a significant role in establishing a successful bending process. In this study, the performance of two lubricants, Hydrodraw 551 and HFO 20, were investigated for bending Dual Phase 780 (DP780) and High Strength Low Alloy 350 (HSLA350) thin-walled steel tubes. Formability success was evaluated in terms of wrinkling, thinning strain and final geometry. Lubricant performance was found to be sensitive to grade and application site. HFO 20 was found to be a poor choice for bending DP780 tube.

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