scholarly journals Numerical and experimental studies on wrinkling control methods of sheet metal part with high curvature and large flange in rubber forming

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988378
Author(s):  
Lei Chen ◽  
Ying Bai ◽  
Zhengyi Jiang ◽  
Huiqin Chen ◽  
Can Wu ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Failure Modes ◽  
Optimal Parameter ◽  
Experimental Studies ◽  
Element Model ◽  
Resistance Force ◽  
Forming Process ◽  
Complex Deformation ◽  
Metal Forming Process ◽  
Rubber Forming

Wrinkling is one of the main failure modes in sheet metal forming process and may lead to assembly problems of the parts. Control of wrinkling is difficult due to the complex deformation behavior of the sheet metal. A finite element model for side blankholder method to control wrinkling was established and used for the simulation. Trials and simulations were conducted to analyze the parameters of wrinkling characteristics. Results show that with the increase in the angle of the side blankholder, the resistance force of the side blankholder decreases. The blank length on the side blankholder should be small enough. The fillet radius of the side blankholder should be large enough to reduce the deformation. The bottom gap between the die and the side blankholder cannot be too large because the support of the blank will decrease in the forming process. In order to verify the simulation results, three blank lengths (20, 15, and 5 mm) over the side blankholder were used in the experiment. The results of the comparison tests testify the reliability of the simulation. The optimal parameter of the blank length is 5 mm. A new clamp method was designed for wrinkling control to overcome the shortcomings of the side blankholder method. The precision of the part met the requirement using soft rubber and two layers of rubber plates.

Process Optimization of Sheet Metal Forming Using Operating Window

2009 ◽  
Author(s):  
Kyungmo Kim ◽  
Jeong Je Yin ◽  
Yong S. Suh
Keyword(s):  
Sheet Metal ◽  
Robust Design ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Failure Modes ◽  
Optimization Techniques ◽  
Forming Process ◽  
Window Method ◽  
Metal Forming Process ◽  
Operating Window

Sheet metal forming process may yield unexpected defective products due to many uncontrollable factors such as irregular material properties, lubricants, and variations of other forming conditions. Traditional design methods based on deterministic optimization theory have limited capability of including such factors. In this paper, we propose a method in determining the optimal condition of a sheet metal forming process with conflicting failure modes. A robust design method is used with computer simulations and optimization techniques. A new SN ratio is proposed based on the operating window method, to improve the problems of traditional SN ratio. The robust design process is applied to a sheet metal forming process for an automobile component, and the effectiveness of the proposed method is verified.

Constitutive Equation for Description of Metallic Materials Behavior during Static and Dynamic Loadings Taking into Account Important Gradients of Plastic Deformation

2012 ◽  
Vol 504-506 ◽  
pp. 697-702 ◽  
Author(s):  
Adinel Gavrus
Keyword(s):  
Constitutive Equation ◽  
Element Model ◽  
Strain Rates ◽  
Forming Process ◽  
Complex Deformation ◽  
Dynamic Loadings ◽  
Metal Forming Process ◽  
Split Hopkinson ◽  
Points Of View ◽  
Materials Behavior

For numerical simulations of rapid forming processes the most used constitutive equations are based on the Johnson-Cook (JC) law and on the Zerilli-Armstrong (ZA) one. Starting from physical points of view, detailed in the first part, the present paper proposes a more general constitutive equation available for both static and dynamic loadings. It is then possible to describe correctly gradients of strain rate, plastic strain and temperature which occur during a complex deformation path of a metal forming process. From this new law, the JC formulation can be easily obtained from an asymptotic variation of the proposed law at high values of strain rates and, in similar way, the ZA formulation is obtained at small values of strain rates. Application to an aluminum alloy AA5083 will be presented to validate the proposed constitutive equation by a Finite Element Model (FEM) of a rapid upsetting test performed with the Split Hopkinson Pressure Bars.

scholarly journals Laser Welding of High-strength Aluminium Alloys for the Sheet Metal Forming Process

Procedia CIRP ◽  
2014 ◽  
Vol 18 ◽  
pp. 203-208 ◽  
Author(s):  
J. Enz ◽  
S. Riekehr ◽  
V. Ventzke ◽  
N. Sotirov ◽  
N. Kashaev
Keyword(s):  
Laser Welding ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Aluminium Alloys ◽  
High Strength ◽  
Forming Process ◽  
Metal Forming Process

scholarly journals Common defects of parts manufactured through single point incremental forming

2021 ◽  
Vol 343 ◽  
pp. 04007
Author(s):  
Mihai Popp ◽  
Gabriela Rusu ◽  
Sever-Gabriel Racz ◽  
Valentin Oleksik
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Metal Forming Process ◽  
Serial Robot ◽  
The Many ◽  
Cold Metal

Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final geometrical accuracy of the parts manufactured through single point incremental forming.

Investigating Bauschinger Effect and Plastic Hardening Characteristics of Sheet Metal under Cyclic Loading

2017 ◽  
Vol 4 (2) ◽  
pp. 1-14 ◽  
Author(s):  
Jasri Mohamad
Keyword(s):  
Cyclic Loading ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Bauschinger Effect ◽  
Low Carbon Steel ◽  
Cyclic Hardening ◽  
Low Carbon ◽  
Forming Process ◽  
Metal Forming Process

To improve sheet metal forming process simulation using finite element method, there is a need to incorporate an appropriate constitutive equation capable of describing the Bauschinger effect and the so-called cyclic transient, derived from a near to actual sheet metal forming process testing tool. A cyclic loading tool has been developed to test and record the characteristics of sheet metal deformation by investigating the Bauschinger effect factors (BEF) and cyclic hardening behaviour. Experimental investigation conducted on low carbon steel and stainless steel demonstrates that the tool is able to record sheet metal behaviour under cyclic loading. The results are analysed for signs of the Bauschinger effect and cyclic hardening effect. It was found that the Bauschinger effect does occur during bending and unbending loadings in sheet metal forming process.

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