ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
This study aims to clarify the process conditions of the UO-tube of a sheet metal of steel. Itprovides a model that predicts not only the correct punch load for drawing, but also the precise finalshape of products after unloading, based on the tensile properties of the material and the geometry ofthe tools used. An elasto-plastic incremental finite-element computer code, based on an updatedLagrangian formulation, was developed to simulate the UO-tube process of sheet metal; the resultsare compared with corresponding experimental results. Special care was taken to formulate accurateboundary conditions of penetration, separation and alternation of the sliding-sticking state of friction,as the contact conditions between the tools and the sheet varied throughout the entire processes ofU-bending and successive O-bending. Calculated sheet geometries and forming force agree well withexperimental data. In particular, selective reduced integration was adopted to formulate the stiffnessmatrix. The extended r-minimum technique was used to deal with the elasto-plastic state and contactproblems at the tool-metal interface. A series of simulations were performed to validate theformulation in the theory, leading to the development of the computer codes. The whole deformationhistory, the distribution of stress and the distribution of strain during the forming process wereobtained by carefully considering the moving boundary condition in the finite-element method. Thesimulation demonstrates clearly the efficiency of the code to simulate various bending processes thatproceed under complicated deformation- and contact-history
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/54/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.340-341.341.pdf
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