ISSN:
1662-9752
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:
One of the most relevant technological parameters for the accurate numerical simulationof the deep drawing process is friction, since the contact between the blank sheet and tools developsfriction forces that act as supplementary boundary conditions that determine the final part shape.Most applications reported in literature are still restricted to Coulomb’s law with a constant frictioncoefficient over the entire process. Although it is consensual that state conditions of contact surfacesand consequently the friction behaviour are influenced by a large number of parameters, there is noagreement about a wide-ranging law to accurately describe the friction evolution. One possibility isto use phenomenological laws that accurately fit experimental data. A Voce type law is used in thiswork to describe the evolution of the friction coefficient over the entire process as function of thecontact pressure. This type of law guarantees a good correlation with experimental data and alsonumerical stability. The Voce type law was implemented in the static implicit code DD3IMP. Theanalysis of the relevance of considering the evolutional friction law in the numerical simulation isperformed for a U-rail. This shape was selected for this study due to the simple deformationmechanisms that are involved, but also because it is a rail specially conceived to emphasize 2-Dspringback defects. The blank sheet material selected is a 6016-T4 aluminium alloy. The plasticbehaviour is modelled using the 1948 Hill’s criterion with isotropic and kinematic hardening. Thenumerical results obtained considering the evolutional friction law are compared with two otherresults obtained with: (i) a constant friction value of 0.10, normally used for this material inindustrial practice and (ii) three constant friction coefficients for each contact zone (flat, die radiusand punch radius)
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/12/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.514-516.1443.pdf
