scholarly journals Investigation on Springback Behavior of Cu/Ni Clad Foils during Flexible Die Micro V-Bending Process

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 892 ◽  
Author(s):  
Chuanjie Wang ◽  
Shan Wang ◽  
Shuting Wang ◽  
Gang Chen ◽  
Peng Zhang
Keyword(s):  
Compressive Stress ◽  
Thin Sheet ◽  
Interface Layer ◽  
Interactive Effects ◽  
Bending Process ◽  
Micro Parts ◽  
Increasing Demand ◽  
Flexible Die ◽  
Springback Angle ◽  
Springback Behavior

With the increasing demand for micro parts using metal laminates in modern production, the manufacturing processes of thin sheet parts have been elevated. However, it is difficult to predict the deformation behavior with miniaturization because of size effects in micro-scale. In this study, the flexible die micro V-bending behavior of Cu/Ni clad foils was investigated. The bending experiments with three different punch angles and Cu/Ni clad foils under different annealed temperatures were performed. The results show that the springback angle increases with the increase of bending angle and annealing temperature. The placement of Cu/Ni clad foils induced compressive stress results in the more obvious thinning of thickness and decreasing of springback angle. The interactive effects of the distribution of deformation zones and compressive stress induced by the interface layer result in the springback behavior of Cu/Ni clad foils during the flexible die micro V-bending process.

Theoretical Investigation of the Bending Process of the Pre-Strained Metal Sheet

2020 ◽  
Vol 299 ◽  
pp. 351-357
Author(s):  
Sergey A. Tipalin ◽  
Michael A. Petrov ◽  
Yuriy A. Morgunov
Keyword(s):  
Thin Sheet ◽  
Bending Moment ◽  
Metal Sheet ◽  
Roll Forming ◽  
Forming Process ◽  
Bending Process ◽  
Punch Radius ◽  
Zero Radius ◽  
Strain Stress ◽  
Roll Forming Process

During the bending operation of the thin sheet materials by the punch with the near-to-zero radius the special technological operation should be carried out. It means that the metal sheet obtained a certain thinning value, which is usually done in the form of the channel-concentrator or groove by pre-drawing operation in a cold state. It follows to the pre-straining and strengthening of the material. The authors investigated the strain hardened sheet's area after roll forming process theoretically, and obtained the strain-stress distribution inside the sheet during the bending operation. It was found out that the increase of the prior deformation during pre-straining in the bend layer follows to the increase of the radial and tangential stresses and displacement of the neutral axis inside the blank during bending operation. As a result, the bending moment changes its values depends on the punch radius and strain hardening.

scholarly journals Experimental study of springback behavior in incremental bending process

2018 ◽  
Vol 15 ◽  
pp. 1290-1297 ◽  
Author(s):  
Feifei Zhang ◽  
Jianbin Ruan ◽  
Ji Zhang ◽  
Kai He ◽  
Ruxu Du
Keyword(s):  
Experimental Study ◽  
Bending Process ◽  
Springback Behavior

Dynamic Characteristics of a Micro-Sheet-Forming Machine System

2012 ◽  
Vol 504-506 ◽  
pp. 599-604 ◽  
Author(s):  
Yi Qin ◽  
Akhtar Razul Razali ◽  
Mei Zhou ◽  
Jie Zhao ◽  
Colin Harrison ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Thin Sheet ◽  
Sheet Forming ◽  
Element Analysis ◽  
Machine System ◽  
Micro Parts ◽  
Thin Sheet Metal ◽  
Tooling System

Dynamic characteristics of a micro-forming machine system are of significant importance to be considered if high-precision micro-parts are to be produced. This is because forming tolerances may be within a range of sub-microns up to 5-15% of the thickness of a thin sheet-metal (e.g. <100µm) being used in micro-sheet-forming. Achievability of the quality parts often vary with the machine-system performance and process parameters being set, and it largely depends on the understanding of the machine and tool system’s dynamic characteristics and effectiveness of the control of the machine and the process. Nevertheless, there has been lack of the effort in this field of research. Significant number of the efforts in this field were focused mainly on discrete and/slow processes where the dynamic characteristics of the forming systems were often neglected. This paper presents the dynamic characteristics of an autonomous micro-sheet-forming machine system and its effect towards the produced parts’ quality. These have been studied by combining finite element analysis and forming experiment, with a particular focus on the combined effects from the machine, tooling system and the sheet-metal feeding system (the strip feeder). The results showed that, besides importance of the dynamic performance of the machine and the tool-system, dynamic characteristics of the material-feeding plays an important part in determining the parts’ quality produced.

An Adaptive-Network-Based Fuzzy Inference System for Predicting Springback of U-Bending

2013 ◽  
Vol 284-287 ◽  
pp. 25-30 ◽  
Author(s):  
Bor Tsuen Lin ◽  
Kun Min Huang ◽  
Chun Chih Kuo
Keyword(s):  
Fuzzy Inference System ◽  
Fuzzy Inference ◽  
Training Data ◽  
Adaptive Network ◽  
Anfis Model ◽  
Inference System ◽  
Bending Process ◽  
Punch Radius ◽  
Triangular Membership Function ◽  
Springback Angle

Springback will occur when the external force is removed after bending process in sheet metal forming. This paper proposed an adaptive-network-based fuzzy inference system (ANFIS) model for prediction the springback angle of the SPCC material after U-bending. Three parameters were selected as the main factors of affecting the springback after bending, including the die clearance, the punch radius, and the die radius. The training data were obtained from results of U-bending experiment. The training data with four different membership functions – triangular, trapezoidal, bell, and Gaussian functions –were employed in the ANFIS to construct a predictive model for the springback of the U-bending. After the comparison of the predicted value with the checking data, we found that the triangular membership function has the best accuracy, which make it the best function to predict the springback angle of sheet metals after U-bending.

An Investigation on Effect of Residual Stress on Springback Behavior of High Strength Steel in U-Bending Process

2011 ◽  
Vol 189-193 ◽  
pp. 2864-2868
Author(s):  
Komgrit Lawanwong
Keyword(s):  
Residual Stress ◽  
Fem Simulation ◽  
Sheet Thickness ◽  
High Strength ◽  
Spring Back ◽  
Workpiece Material ◽  
Bending Process ◽  
Commercial Program ◽  
Deform 2D ◽  
Springback Behavior

Bending process is an important process in the metal sheet forming in many industries. The main problem of the bending process is the spring-back phenomenon after removing the punch. This research aims the investigation on effect of residual stress on springback behavior of sheet metal in U bending process. The corner setting technique and bottoming process were designed for experiments. The corner setting technique and bottoming has reduced the thickness in bending area to 5, 10, 15 and 20 percent of the original sheet thickness. Clearance between punch and die of both processes was equal to same the thickness. The residual stress value and springback phenomenal were investigated by commercial program code DEFORM 2D which was able to analyze the effect stress and force in bending area. Electrolytic zinc coated carbon steel grade JIS; SECC, JIS; 440 and JIS; 590 which having the thickness of 1 mm were employed as the workpiece material for all experiments. The result of three materials in conventional U bending die shows larger spring back than the corner setting technique and bottoming process. Moreover, the corner setting technique reduces spring back value in bending process but requires high bending force. Corner setting technique and bottoming process at 15% and 20% shows that the spring go of all parts. The FEM simulation results explained the effect of residual stress to springback phenomenal. Comparisons between experimental and finite element method results were also performed.

Effect of Strain-Hardening Induced Grain Refinement on Springback in Microtube Press Bending Process

2012 ◽  
Vol 528 ◽  
pp. 111-118
Author(s):  
Cho-Pei Jiang
Keyword(s):  
Grain Size ◽  
Strain Hardening ◽  
Grain Refinement ◽  
Microstructure Development ◽  
Bending Angle ◽  
The Press ◽  
Bending Process ◽  
Twin Band ◽  
Three Stages ◽  
Springback Behavior

Seamless stainless microtube (SUS 304L) was selected for a detailed investigation of the strain-hardening influencing grain refinement and microstructural evolution during processing by varying press bending angles. The problem was approached in three stages. First, the microtubes were annealed to examine the initial grain size and analyzed the effect of grain size on mechanical properties by performing a tensile test. Second, a microtube press bending system was developed to observe springback behavior. Third, the microstructure of the microtube with different press bending angle was observed to investigate the effect of strain-hardening induced grain refinement on springback behavior. As a result, the occurrence of grain refinement reduced the springback amount. The mechanism of microstructure development in the shear zone during the press bending process is needle like, twin band and equiaxed and small rounded grains sequentially.

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.

An Experimental Study of the Influence of Size Effect on Springback of Micro Sheet Forming

2006 ◽  
Author(s):  
Jenn-Terng Gau ◽  
Chris Principe ◽  
Fengchen Yang
Keyword(s):  
Experimental Study ◽  
Size Effects ◽  
Low Cost ◽  
Thin Sheet ◽  
Sheet Forming ◽  
Three Point Bending ◽  
Key Factor ◽  
Thin Sheet Metal ◽  
Springback Behavior ◽  
Grain Diameter

An efficient and low cost experiment was conducted to investigate the influence of grain size effects on springback of thin sheet metal. A three-point bending setup was used to test Aluminum 1100 O-Temper and Brass 26000 1/2 Hard (H02). Thickness and average grain diameter were controlled to achieve a range of desired T/D (thickness/grain diameter) ratios because T/D ratio is a key factor that influences the springback behavior in micro sheet forming. The results from this experiment show that as T/D ratio becomes smaller (T/D &gt; 1 → 1) the springback amount increases at a decreasing slope. And as T/D continues to become even smaller (T/D &lt; 1) the springback amount begins to decrease. These behaviors demonstrate the influence of size effects on springback.

Sign in / Sign up

Export Citation Format

Share Document