Issues in modeling slitting of magnetic tapes

Abstract

In order to quantify and understand the driving force for film layer fracture, delamination, and the cutting phenomena in general, an idealized two-dimensional "slitting" model was developed. The model includes two lower ("female") knives supporting the tape, through which a single upper ("male") knife is passed. The knife surfaces are modeled as frictional rigid surfaces and the displacement of the male knife is imposed. The tape is modeled as an elastic-plastic material with a critical shear strain energy and hydrostatic pressure criteria for element-localized failure. The model follows a "quasi-static" dynamic explicit formulation scheme that handles highly nonlinear responses very efficiently. This technique has been widely used in the modeling of metal cutting and is able to capture many of the major features of the slit edge morphology but shows a strong sensitivity to mesh resolution.

Criteria for success of the model includes invariance of the edge morphology with mesh scale and agreement between predicted and observed slit edge morphology. Results showed a strong dependence on tape materials properties. The major focus of this work is the interrelationship of mesh scale and the failure criterion imposed.