The strain path and forming limit analysis of the lubricated sheet metal forming process

2007 ◽  
Vol 47 (7-8) ◽  
pp. 1311-1321 ◽  
Author(s):  
Tung-Sheng Yang
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Limit Analysis ◽  
Metal Forming ◽  
Strain Path ◽  
Forming Limit ◽  
Forming Process ◽  
Metal Forming Process

scholarly journals Experimental And Theoretical Determination Of Forming Limit Curve

2015 ◽  
Vol 60 (3) ◽  
pp. 1881-1886
Author(s):  
J. Adamus ◽  
K. Dyja ◽  
M. Motyka
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Fracture Initiation ◽  
Forming Limit ◽  
Forming Process ◽  
Element Analysis ◽  
Metal Forming Process

Abstract The paper presents a method for determining forming limit curves based on a combination of experiments with finite element analysis. In the experiment a set of 6 samples with different geometries underwent plastic deformation in stretch forming till the appearance of fracture. The heights of the stamped parts at fracture moment were measured. The sheet - metal forming process for each sample was numerically simulated using Finite Element Analysis (FEA). The values of the calculated plastic strains at the moment when the simulated cup reaches the height of the real cup at fracture initiation were marked on the FLC. FLCs for stainless steel sheets: ASM 5504, 5596 and 5599 have been determined. The resultant FLCs are then used in the numerical simulations of sheet - metal forming. A comparison between the strains in the numerically simulated drawn - parts and limit strains gives the information if the sheet - metal forming process was designed properly.

Optimum of Drawbead Design and Restraining Forces by Sensitivity Analysis Method Combined with Inverse Approach in Sheet Metal Forming Process

2012 ◽  
Vol 502 ◽  
pp. 369-375
Author(s):  
Guo Feng Yi ◽  
Yu Qi Liu ◽  
Ting Du
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Forming Limit ◽  
Limit Curve ◽  
Forming Process ◽  
Inverse Approach ◽  
Sensitivity Analysis Method ◽  
Metal Forming Process

A improved algorithm to optimize the restraining force of equivalent drawbead was proposed base on BGFS(Broyden-Fletcher-Goldfarb-Shanno) algorithm combined with a simplified finite element method called inverse approach(IA). The forming limit curve (FLC) and the wrinkle limit curve (WLC) were considered as the objective function to reflect the influence of Fracture and wrinkle defect in sheet metal forming process. The optimized result was more accurate than those procedures only consider the variation of thickness distribution. The optimized process was also very efficient due to the simplified assumptions of the IA. Two stamping parts were presented to validate the accuracy of this optimum algorithm.

Studies on the Processes Design of Multi-Step Sheet Metal Forming

2010 ◽  
Vol 146-147 ◽  
pp. 1855-1858
Author(s):  
Wei Chen ◽  
Ming Yan Wu ◽  
Zhong Fu Huang ◽  
Yi Ding ◽  
Feng Ze Dai
Keyword(s):  
Finite Element Analysis ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Strain Path ◽  
Forming Process ◽  
Element Analysis ◽  
Design Rules ◽  
Forming Quality ◽  
Metal Forming Process

It is well known that the design of multi-step sheet metal forming process is rather difficult. Even small errors may cause significant quality problem. In recent years, finite element analysis (FEA) has being considered as an essential tool for the design. Using a commercial FEA package, DYNAFORM, this paper studies the design of multi-step sheet metal forming processes, especially on how the design of the intermediate steps affect the forming quality. For a rectangle box with a rectangle protrusion inside, several different forming schemes are investigated by means of FEA. The study reveals that the strain path plays an important role. Accordingly, a couple of design rules are suggested.

Sheet Metal Forming Limit Prediction with Maximum Thickness Reduction Ratio

2011 ◽  
Vol 314-316 ◽  
pp. 999-1004
Author(s):  
Jie Shi Chen ◽  
Jun Chen
Keyword(s):  
Numerical Simulation ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Strain Path ◽  
Reduction Ratio ◽  
Thickness Reduction ◽  
Forming Limit ◽  
Forming Process ◽  
Maximum Thickness

Maximum thickness reduction ratio is used to predict sheet metal forming limit in the numerical simulation of forming process. The maximum thickness reduction ratio under different stain path is not a constant for the same material. The effect of strain path and strain hardening exponent on forming limit is considered. The relationship between the maximum thickness reduction ratio that the material can obtained and the strain path between tensile to equi-biaxial is established. The parameter in the criterion can be determined by tensile experiment combined with numerical simulation of the same forming process. Then the limit strains under other linear strain paths between tensile to equi-biaxial can be determined by the criterion combined with numerical simulation of corresponding forming process. Forming limits of three kinds of sheet metals are predicted with the modified maximum thickness reduction ratio criterion. Good agreement is achieved between the predicted data and the experimental data.

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

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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