The defect in work rolls directly influence the forming cost and the final shape of the product. The researchers tend to investigate the thermo-mechanical stress in work roll of rolling machines. These stresses may reduce the roll life. Since the investigation of the thermo-mechanical stress in work roll with real-conditions is complex, comprehensive studies by means of numerical methods are av...

We calculate the friction force acting on a hard cylinder or spherical ball rolling on a flat surface of a viscoelastic solid. The rolling-friction coefficient depends non-linearly on the normal load and the rolling velocity. For a cylinder rolling on a viscoelastic solid characterized by a single relaxation time Hunter has obtained an exact result for the rolling friction, and our result is in...

Flexible display has been attracting attention in the research field of next generation display in recent years. And polymer is a candidate material for flexible displays as it takes advantages including transparency, light weight, flexibility and so on. Rolling process is suitable and competitive process for the high throughput of flexible substrate such as polymer. In this paper, we developed...

We study the problem of flatness of two-input driftless control systems. Although a characterization of flat systems of that class is known, the problems of describing all flat outputs and of calculating them is open. We show that all x-flat outputs are parameterized by an arbitrary function of three canonically defined variables. We also construct a system of 1 order PDE’s whose solutions give...

The resistance against rolling of a rigid cylinder on a flat viscous surface is investigated. We found that the rolling-friction coefficient reveals strongly non-linear dependence on the cylinder’s velocity. For low velocity the rolling-friction coefficient rises with velocity due to increasing deformation rate of the surface. For larger velocity, however, it decreases with velocity according t...

Wepresent a fundamental study of the frictional performance of silicamicrospheres, either 4, 2, or 0.5 mm in diameter, on a silicon substrate. The tribological properties of these rolling systems were measured with a ball-on-flat tribometer at various loads. The frictional performance of the rolling systems is found to be highly dependent on load and sphere diameter. Rolling motion was confirme...

The cold rolling of flat metal products especially in tandem or multi-stand mills is a highly complex process where the product quality is influenced by various aspects. With the help of a hardware-in-the-loop simulator, the complete rolling process can be simulated and tested in real-time. This allows pre-commissioning and pre-optimizations before the actual commissioning work is done on the p...

Rolling friction has been explained in terms of crack propagation through an adhesive joint. The contact between a smooth cylinder and flat has been regarded as an adhesive junction bounded by two cracks moving in the same direction at the same speed, one crack continually opening and one closing. Propagation of these cracks requires a force which is calculated from crack theory and shown to be...

We study decay of a flat unstable Dp-brane in the context of boundary string field theory action. Three types of homogeneous rolling tachyons are obtained without and with Born-Infeld type electromagnetic field.