Asymptotic Stability Analysis for Sheet Metal Forming—Part II: Application

2000 ◽  
Vol 67 (4) ◽  
pp. 691-696 ◽  
Author(s):  
W. Scherzinger ◽  
E. Chu ◽  
N. Triantafyllidis
Keyword(s):  
Experimental Investigation ◽  
Stability Analysis ◽  
Stress State ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Deformation Theory ◽  
Proportional Loading ◽  
Plastic Buckling ◽  
Axisymmetric Solution ◽  
Previous Experimental Investigation

The general asymptotic method proposed in Part I is applied to the investigation of the puckering instability in the hemispherical cup test. Both a membrane and a shell stress state for the principal axisymmetric solution have been considered. Due to the possibility of strong deviations from proportional loading in some cases, a corner theory of plasticity is also employed, in addition to the standard J2 deformation theory which is often used in plastic buckling calculations. Results are compared to a previous experimental investigation for brass specimens. [S0021-8936(00)00904-1]

Numerical modeling crack propagation of sheet metal forming based on stress state parameters using XFEM method

2013 ◽  
Vol 69 ◽  
pp. 311-326 ◽  
Author(s):  
Fengmei Xue ◽  
Fuguo Li ◽  
Jiang Li ◽  
Min He ◽  
Zhanwei Yuan ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Stress State ◽  
Crack Propagation ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming

Experimental investigation into a new hybrid-forming process: Incremental stretch drawing

2016 ◽  
Vol 232 (3) ◽  
pp. 475-486 ◽  
Author(s):  
Puneet Tandon ◽  
Om Namah Sharma
Keyword(s):  
Experimental Investigation ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Lead Time ◽  
Drawing Process ◽  
Forming Process ◽  
Setup Cost ◽  
Deep Drawing Process ◽  
Incremental Sheet Metal Forming

Incremental sheet metal forming is an evolving process, which is suitable for the production of limited quantities of sheet metal components. The main advantages of this process over conventional forming processes are reduced setup cost and manufacturing lead time, as it eliminates the need of special purpose dies, improves formability, reduces forming forces, and provides process flexibility. The objective of this work is to investigate a new hybrid-forming process, which intends to combine incremental sheet metal forming with deep drawing process and has been named as “incremental stretch drawing.” A number of setups and fixtures were developed to carry out experiments to achieve incremental stretch drawing and understand the mechanism of the process. This process addresses some of the challenges of incremental sheet metal forming, that is, limited formability in terms of forming depth, especially at steeper wall angles and subsequent thinning of sheet. It is observed that the proposed process is able to reduce thinning as much as about 300%, considering same forming depth for incremental sheet metal forming and incremental stretch drawing processes. Improvement in formability, in terms of forming depths, also has been observed to be near about 100% in particular cases.

The Effect of Macroscopic Stress State on Transformation Rate in TRIP-Assisted Steels

2007 ◽  
Vol 340-341 ◽  
pp. 1067-1072
Author(s):  
Ti Kun Shan ◽  
Wei Gang Zhang ◽  
Zhong Qin Lin ◽  
Shu Hui Li
Keyword(s):  
Stress State ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Transformation Rate ◽  
Transformation Kinetics ◽  
Forming Process ◽  
Multiaxial Stress State ◽  
Single Shear

The dependence of the transformation rate on the multiaxial stress state corresponding to different loading paths is investigated. On the basis of the single shear, uniaxial tension, plane strain and equibiaxial stretching tests, the influence of stress state on stability of retained austenite is analyzed and an equation of transformation kinetics is developed. In sheet metal forming, the material undergoes complicated deformation, the prediction of the volume fraction of retained austenite during forming process is essential to estimate the contribution of the TRIP effect to improving formability. To this aim, the volume fraction of retained austenite in the part’s different regions has been calculated using finite element method. The calculated results were compared with the experimental data measured in deep drawing experiments.

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