Development of Forming Method for Aluminum Alloy Channel with Curvature and Modified Cross-Section Shape in Rotary Draw Bending

2015 ◽  
Vol 1110 ◽  
pp. 130-135
Author(s):  
Kosuke Ito ◽  
Noah Utsumi ◽  
Masashi Yoshida

In the manufacturing industry, metal cross-sections and profiles are manufactured by using extrusion as the primary process. Subsequently, the products are generally subjected to bending in a secondary process. However, long products with the same cross-sections are typically mass-produced by one extrusion. In industries that manufacture such products, there have been increasing demands for flexible manufacturing systems that can be used for low-volume diverse products. However, it is difficult to adapt traditional manufacturing systems to this requirement. In this study, we aimed to develop a new bending method that can be used to deform the cross-sections of existing versatile extruded sections, such as channel materials and rectangular tubes, to several types of cross-sectional shapes and to simultaneously impose a desired curvature on them. The rotary draw bending process for an aluminum alloy channel material without tensile flanges was investigated by using the finite element method and experiments. The effects of the bend angle and thickness ratio on the cross-sectional deformation were examined. Furthermore, the influence of additional axial tension on the channel materials was studied. Additional axial tension can be used to control the outward and inward deformations of the webs. In addition, it was confirmed that the axial tension is very effective in preventing wrinkling and folding.

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098430
Author(s):  
Huifang Zhou ◽  
Shuyou Zhang ◽  
Lemiao Qiu ◽  
Zili Wang

The springback directly affects the forming accuracy and quality of metal bent-tube, and accurate springback prediction is the key to the springback compensation and control. This paper investigates the springback of mandrel-less rotary draw bending (MLRDB) of circular metal tubes, and an innovative method, springback angle prediction considering the interference of cross-sectional distortion (IoCSD-SAP), is proposed. The digit decomposition condition variational auto-encoder generative adversarial network (D2CVAE-GAN) is developed to augment the data samples. Considering the nonlinear interference of the cross-sectional distortion on springback, auxiliary extended radial basis function (AE-RBF) is proposed. It establishes the mapping relationship between the characteristic parameters and cross-sectional distortion. By extracting the information encode of cross-sectional distortion as the condition input, this model realizes the condition prediction of springback angle. Taking MLRDB of 6060-T6 Al-alloy circular tube as a case study, the proposed method, IoCSD-SAP, is verified. According to the experimental results, the mean absolute percentage error (MAPE) for the springback angle of our proposed method is 4.73%, and three different analytical models are 38.92%, 14.39%, and 14.22%, respectively. It can be seen that our proposed method significantly improves the prediction accuracy of springback angle. For the springback angle prediction of circular metal tube in MLRDB, the data augmentation can effectively reduce the generalization error and improve the prediction accuracy. The nonlinear interference of the cross-sectional distortion on springback should be taken into account to improve the accuracy and robustness of the springback prediction model.


2013 ◽  
Vol 554-557 ◽  
pp. 1394-1399 ◽  
Author(s):  
Torgeir Welo ◽  
Fredrik Widerøe

European manufacturing companies are currently facing increased competition as a result of intensified globalization in the market and supply base. One strategy to meet this challenge is to develop and manufacture higher quality products at reduced cost. Metal forming is a typical manufacturing operation where improved technology can create advantages in the market place through higher value-added products. In the automotive industry, for example, improved shaping capabilities of profiles will improve product functionality, while reducing system cost due to reduction of part count and subsequent assembly operations such as welding. In addition, improved dimensional accuracy will provide benefits in terms of reduced quality costs and, sometimes, eliminating downstream processing steps such as calibration or machining. Rotary draw bending is typically used to manufacture profile-based shapes bent at tight radii with reasonable dimensional accuracy. The advantage of this process is low operational cost combined with relatively high flexibility, particularly with regard to bend angle. On the other hand, the disadvantage associated with the method is limited abilities to control local distortions of the cross section without taking special actions such as applying external stretching or complex tooling that ultimately would increase the investment and operational cost. The objective of the present paper is to identify the most important factors that influence cross-sectional distortions and quantify their impact on dimensional accuracy in draw bending, by performing a series of experiments in an industry-type draw bender. In order to accommodate different cross-sectional geometries, a flexible, modular tool concept was developed. AA6xxx aluminum alloy profile with different cross-sectional geometries (width, depth, thicknesses), single and multi-camber, were bent at different radii and bend angles, while measuring local distortions of the cross sections. The results have been presented in diagrams denoted flatness limit curves, showing the impact of various geometry (and material) parameters on local deformations of individual cross sectional members. The results show that the flange width (i.e. the free span between webs) is the main factor with regard to distortions, followed by wall thickness and bending radius and, finally, depth of the cross sections. Material parameters seem to have limited effect for the alloy tempers investigated. Attempts have been made to interpret the mechanisms associated with the development of local cross sectional distortions with the purpose of developing a practical design tool based on analytical calculations. The very first results show reasonably well agreement in the cases when local buckling of the internal compressive flange is less predominant.


2011 ◽  
Vol 117-119 ◽  
pp. 1839-1842
Author(s):  
Gang Yao Zhao ◽  
Rang Yang Zhang ◽  
Yu Li Liu ◽  
Zheng Hua Guo ◽  
Ping Fang

To obtain the cross-sectional distortion of thin-walled rectangular tube in rotary draw bending process accurately, a new method to exactly describe the distortion has been proposed. The coupling between the convex of the tube side walls and the concave of the tube flanges is considered in the distortion modeling. Combined with the experiments, the cross-sectional distortion obtained using the new distortion model are compared with the previous ones obtained without considering the convex based on numerical simulations. The results show that cross-sectional distortion obtained by current model is closer to reality than the previous ones. The distortion by current model is more safety in the practical bending process.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1956
Author(s):  
Xinwei Wang ◽  
Jie Xu ◽  
Minghan Ding ◽  
Yanhu Zhang ◽  
Zhenlong Wang ◽  
...  

Bent micro-tubes have been frequently applied in electronics, medical devices and aerospace for heat transfer due to the increasing heat flux in high-density electric packages. Rotary-draw bending (RDB) is a commonly used process in forming tubes due to its versatility. However, the control of forming defects is the key problem in micro-tube bending in terms of wall thinning, cross-sectional deformation and wrinkling. In this paper, a three-dimensional (3D) finite-elements (FE) modeling of electrically-assisted (EA) RDB of 6063 aluminum alloy micro-tubes is developed with the implicit method in ABAQUS. The multi-field coupled behavior was simulated and analyzed during the EA RDB of micro-tubes. Several process parameters such as micro-tube diameter, bending radius, current density and electrical load path were selected to study their effects on the bending defects of the Al6063 micro-tubes. The simulated results showed that the cross-sectional distortion could be improved when electrical current mainly pass through the vicinity of the tangent point in the micro-tube RDB, and the cross-sectional distortion tended to decrease with the increases of current density and tube diameter, and the decreases of bending speed and radius. A trade-off should be made between the benefit and side effect due to electrical current since the risk of wall thinning and wrinkling may increase.


2010 ◽  
Vol 638-642 ◽  
pp. 675-680 ◽  
Author(s):  
Martina Thomann ◽  
Nina von der Höh ◽  
Dirk Bormann ◽  
Dina Rittershaus ◽  
C. Krause ◽  
...  

Current research focuses on magnesium based alloys in the course of searching a resorbable osteosynthetic material which provides sufficient mechanical properties besides a good biocompatibility. Previous studies reported on a favorable biocompatibility of the alloys LAE442 and MgCa0.8. The present study compared the degradation process of cylindrical LAE442 and MgCa0.8 implants after 12 months implantation duration. Therefore, 10 extruded implants (2.5 x 25 mm, cross sectional area 4.9 mm²) of both alloys were implanted into the medullary cavity of both tibiae of rabbits for 12 months. After euthanization, the right bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical) and nine uniformly distributed cross-sections of each implant were used to determine the residual implants´ cross sectional area (Software AxioVisionRelease 4.5, Zeiss). Left implants were taken out of the bone carefully. After weighing, a three-point bending test was carried out. LAE442 implants degraded obviously slower and more homogeneously than MgCa0.8. The mean residual cross sectional area of LAE442 implants was 4.7 ± 0.07 mm². MgCa0.8 showed an area of only 2.18 ± 1.03 mm². In contrast, the loss in volume of LAE442 pins was more obvious. They lost 64 % of their initial weight. The volume of MgCa0.8 reduced clearly to 54.4 % which corresponds to the cross sectional area results. Three point bending tests revealed that LAE442 showed a loss in strength of 71.2 % while MgCa0.8 lost 85.6 % of its initial strength. All results indicated that LAE442 implants degraded slowly, probably due to the formation of a very obvious degradation layer. Degradation of MgCa0.8 implants was far advanced.


2020 ◽  
Author(s):  
J. Lee ◽  
et al.

<div>Figure 6. Interpretative cross sections illustrating the cross-sectional geometry of several paleovalleys. See Figure 3 for location of all cross sections and Figure 8 for location of cross section CCʹ. Cross sections AAʹ and BBʹ are plotted at the same scale, and cross section CCʹ is plotted at a smaller scale. Figure 6 is intended to be viewed at a width of 45.1 cm.</div>


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xibing Hu ◽  
Rui Chen ◽  
Yuxuan Xiang ◽  
Yafang Chen ◽  
Qingshan Li

Steel structures are usually damaged by disasters. According to the influence law of the damage on the elastic modulus of steel obtained by the mechanical test of damaged steel, the average elastic moduli of H-section steel members were analyzed. The equations for calculating the average elastic moduli of damaged H-section steel members at different damage degrees were obtained. By using the analytical cross-sectional method, the cross-sectional M-Φ-P relationships and the dimensionless parameter equations of the H-sections in the full-sectional elastic distribution, single-sided plastic distribution, and double-sided plastic distribution were derived. On the basis of the cross-sectional M-Φ-P relationships and dimensionless parameters of actual steel members, the approximate calculation equations for the damaged cross sections were obtained. The Newmark method was used to analyze the deformation of damaged steel columns. Analytical results show good agreement with the test results. The equations and methods proposed in this study have high computational accuracy, and these can be applied to the cross-sectional M-Φ-P relationships and deformation calculation of damaged steel members.


2021 ◽  
Author(s):  
Xu Yin ◽  
Zhixun Yang ◽  
Dongyan Shi ◽  
Jun Yan ◽  
Lifu Wang ◽  
...  

Abstract The umbilical which consists of hydraulic tubes, electrical cables and optical cables is a key equipment in the subsea production system. Each components perform different physical properties, so different cross-sections will present different geometrical characteristic, carrying capacities, the cost and the ease of manufacture. Therefore, the cross-sectional layout design of the umbilical is a typical multi-objective optimization problem. A mathematical model of the cross-sectional layout considering geometric and mechanical properties is proposed, and the genetic algorithm is introduced to copy with the optimization model in this paper. A steepest descent operator is embedded into the basic genetic algorithm, while the appropriate fitness function and the selection operator are advanced. The optimization strategy of the cross-sectional layout based on the hybrid genetic algorithm is proposed with the fast convergence and the great probability for global optimization. Finally, the cross-section of an umbilical case is performed to obtain the optimal the cross-sectional layout. The geometric and mechanical performance of results are compared with the initial design, which verify the feasibility of the proposed algorithm.


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