Study of NC Cold Tube Bending Spring-Back Characteristics

2010 ◽  
Vol 154-155 ◽  
pp. 202-208 ◽  
Author(s):  
Yi Nan Lai ◽  
Sheng Le Ren ◽  
Zeng Lou Li ◽  
Jun Tao Gu ◽  
Guang Fei Wu
Keyword(s):  
High Reliability ◽  
Prediction Equation ◽  
Strong Nonlinearity ◽  
Spring Back ◽  
Tube Bending ◽  
Bending Angle ◽  
Bending Process ◽  
Elasto Plasticity ◽  
Bending Radius ◽  
Back Angle

The unloading spring-back of tubes during its manufacturing process shows a strong nonlinearity, which greatly influences the precision of parts. In this paper, the strain distribution of bending tubes was analyzed based on the elasto-plasticity theory, and the theoretical equation for spring-back of tubes was derived. The numerical simulation model for cold tube-bending process was developed with prediction error of 9% compared with experimental results, indicating high reliability of the model. The 12Cr1MoV and 20G tubes were used to analyze the effects of bending angle, bending radius and bending speed on the spring-back of tubes. The prediction equation of spring-back was built, which shows that the spring-back tendency was in accordance with theoretical analysis results. The simulated results show that the spring-back angle is linearly proportional to the bending angle within a certain range. In addition, it is proportional to the relative bending radius and the bending speed.

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.

scholarly journals Experimental Investigation of the Effects of Irradiating Schemes in Laser Tube Bending Process

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1123
Author(s):  
Mehdi Safari ◽  
Ricardo J. Alves de Sousa ◽  
Jalal Joudaki
Keyword(s):  
Laser Beam ◽  
Contact Process ◽  
Steel Tube ◽  
Thickness Variation ◽  
Tube Bending ◽  
Lateral Bending ◽  
Bending Angle ◽  
Laser Tube ◽  
Bending Process ◽  
Thickness Variations

The laser tube bending process (LTBP) process is a thermal non-contact process for bending tubes with less springback and less thinning of the tube. In this paper, the laser tube bending process will be studied experimentally. The length of irradiation and irradiation scheme are two main affecting process parameters in the LTBP process. For this purpose, different samples according to two main irradiation schemes (Circular irradiating scheme (CIS) and axial irradiating scheme (AIS)) and different lengths of laser beam irradiation (from 4.7 to 28.2 mm) are fabricated. The main bending angle of laser-bent tube, lateral bending angle, ovality, and thickness variations is measured experimentally, and the effects of the irradiating scheme and the length of irradiation are investigated. An 18 mm diameter, 1 mm thick mild steel tube was bent with 1100 Watts laser beam. The results show that for both irradiating schemes, by increasing the irradiating length of the main and lateral bending angle, the ovality and thickness variation ratio of the bent tube are increased. In addition, for a similar irradiating length, the main bending angle with AIS is considerably higher than CIS. The lateral bending angle by AIS is much less than the lateral bending angle with CIS. The results demonstrate that the ovality percentage and the thickness variation ratio for the laser-bent tube obtained by CIS are much more than the values associated with by AIS laser-bent tube.

Numerically modeling spring back and spring go amounts and bending deformations of Cr-Mo alloyed sheet material

2020 ◽  
Vol 62 (12) ◽  
pp. 1265-1272
Author(s):  
Mustafa Özdemir ◽  
Hakan Dilipak ◽  
Bülent Bostan
Keyword(s):  
Heat Treatment ◽  
Mathematical Models ◽  
Deformation Zone ◽  
Sheet Material ◽  
Analysis Program ◽  
Spring Back ◽  
Forming Process ◽  
Bending Angle ◽  
Heat Treated ◽  
Bending Process

Abstract In the study conducted for this contribution, sheet material 4 mm thick, non-heat treated (II), normalized (NH) and tempering heat treatment implemented (TH), were formed at a bending angle of 90°. As a result of the forming process, the effects of the R2, R3, R4, R5, and R6 mm punch tip radii on spring back and spring go values were investigated. The bending operations were carried out by waiting for the punch in the material bending zone for 30 sec and then lifting. The samples were extracted from the middle deformation zone of the II, NH and TH applied sheet material, to which the bending process was applied, following which their ferrite phase, pearlite and martensite structures were microstructurally analyzed. A Minitab analysis program was used to investigate the effect of the bending parameters on the sheet material’s spring-back and spring-go behavior. Moreover, the effects of bending parameters were investigated by creating numerical and mathematical models. Thus, it was determined that spring-go behavior occurred on the II and NH applied sheet material, while spring-back behavior occurred on the TH applied material.

scholarly journals 90 degrees two-angle bending method with due to blank’s elastic spring back properties

2018 ◽  
Vol 224 ◽  
pp. 01043
Author(s):  
Elena Nesterenko ◽  
Alexander Kuzin
Keyword(s):  
Tool Design ◽  
Spring Back ◽  
Technological Parameters ◽  
Elastic Bar ◽  
Bending Process ◽  
New Process ◽  
Bending Radius ◽  
Current Article ◽  
Strain Stress ◽  
Elastic Spring

Current article presents 90 degrees two-angle bending new process chart with usage of tool with elastic bars. Tool design allows considering elastic blank’s springback to get more precise bending radius. Usage of elastic bars makes two-angle bending process more producible and costless as there no need to make additional operations of geometry defects correction. In that article, bending technological parameters are determined. Strain-stress blank’s conditions during processing is describe. Analytical calculations are made and elastic bar sizes for different blank material are demonstrated.

Wrinkling Limit in Tube Bending

2000 ◽  
Vol 123 (4) ◽  
pp. 430-435 ◽  
Author(s):  
Xi Wang ◽  
Jian Cao
Keyword(s):  
Material Properties ◽  
Deformation Theory ◽  
Energy Approach ◽  
Tube Bending ◽  
Predictive Tool ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Bending Radius ◽  
Thin Walled ◽  
Doubly Curved

Thin-walled tube bending has found many of its applications in the automobile and aerospace industries. This paper presents an energy approach to provide the minimum bending radius, which does not yield wrinkling in the bending process, as a function of tube and tooling geometry and material properties. A doubly-curved sheet model is established following the deformation theory. This approach provides a predictive tool in designing/optimizing the tooling parameters in tube bending.

Study on Spring-Back of CU11000 Clad AL1050 Sheets

2014 ◽  
Vol 941-944 ◽  
pp. 1688-1691
Author(s):  
Shou Fa Liu ◽  
Fei Xue ◽  
Song Lin Wu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Spring Back ◽  
Bend Radius ◽  
Cu Content ◽  
Element Simulation ◽  
Bending Process ◽  
Clad Metals ◽  
Simulation And Experiment ◽  
Back Angle

This study is aimed to investigate the spring-back angle of clad metal sheet in bending process by using finite element simulation and experiment to meet the growing requires in the application of clad metals. In this study, the clad metals processed into 1mm thick from CU11000 and AL1050 were bent 90o over a die with a bend radius of 1mm. The results show that there is not any relative sliding, crushing or peeling occurred in the junction of the clad material during the bending process, the spring-back angle of the clad metal is always smaller than each single metal and the CU content increasing also caused spring-back angle become small. The configuration of a harder material (CU11000) in tensile side also has a smaller spring-back angle.

scholarly journals Parametric Analysis of Tube during Bending Operation

2019 ◽  
Vol 8 (10) ◽  
pp. 1793-1799
Keyword(s):  
Software Package ◽  
Parametric Analysis ◽  
Air Conditioning ◽  
Industrial Applications ◽  
Furniture Industry ◽  
Bending Angle ◽  
Shipbuilding Industry ◽  
Material Deformation ◽  
Bending Process ◽  
Bending Radius

Bent tubes have a lot of various industrial applications. It is required for the transportation of fluids or gases. It also used as construction elements in all industries like car, aviation and shipbuilding industry, refrigeration and air conditioning technology, furniture industry. The objective of this paper is to understand the material deformation occurring during the bending of the tube bends and study the effect of parameters viz. bending radius, bending angle, springback on ovality of tube during bending operation. Tube undergoes certain deformation during the bending process which introduces various defects in the tube bends. This will lead the acceptability of tube bends for certain application. For better understanding the approximation of the defect it is necessary to reduce it at the manufacturing level itself. The testing uses different bending die to differ the bending radius and tests are performed at different bending angle. These whole data has been used to find the different defects and also to find the stress induced in the bends using FEA software package.

Theoretical, Numerical and Experimental Investigation of the Effects of Manufacturing Process Parameters on Thin-Walled Tube Bending Defects

2009 ◽  
Vol 83-86 ◽  
pp. 1107-1112
Author(s):  
J. Taheri Kahnamouei ◽  
Mohammad Sedighi
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Thickness Ratio ◽  
Outer Diameter ◽  
Tube Bending ◽  
Effective Parameters ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Bending Radius ◽  
Thin Walled

The aim of this paper is to survey thin-walled tube bending process (without use of mandrel and booster). In tube bending process there are several effective parameters such as wall thickness, outer diameter-to-wall thickness ratio, and centerline bending radius-to-outer diameter ratio. Any mismatch in selecting these parameters would cause defects like wrinkling, variation in wall thickness, and cross section distortion. Firstly, the effects of these parameters on the initiation of the wrinkle, depth of wrinkling, change in wall thickness, and cross section distortion are studied. For this purpose, an FE commercial code has been used to simulate the process. Then, a series of experimental tests have been carried out to verify the results simulation. A comparison between analytical and experimental results shows a reasonable agreement with each other. Based on this comparison, it has been observed that there is a critical bending radius for any tube with a certain radius and thickness, in which the wrinkling begins to occur. For a certain bending angle and radius, it have been observed that the depth of wrinkling, change in wall thickness, and cross section distortion increase with reduction in wall thickness and outer diameter-to-wall thickness ratio

Wrinkling Limit in Tube Bending

2000 ◽  
Author(s):  
Xi Wang ◽  
Jian Cao
Keyword(s):  
Material Properties ◽  
Deformation Theory ◽  
Energy Approach ◽  
Tube Bending ◽  
Predictive Tool ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Bending Radius ◽  
Thin Walled ◽  
Doubly Curved

Abstract Thin-walled tube bending has found many of its applications in the automobile and aerospace industries. This paper presents an energy approach to provide the minimum bending radius, which does not yield wrinkling in the bending process, as a function of tube and tooling geometry and material properties. A doubly-curved sheet model is established following the deformation theory. This approach provides a predictive tool in designing/optimizing the tooling parameters in the tube bending.

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