Ongoing

Dynamics of cables:

Dormant

Thermal ratcheting: It is observed that pipes exposed to a sharp and oscillating temperature front in the axial direction bulge radially outwards. This bulging is tangible and irreversible and occurs within a few cycles of the thermal oscillation. Obviously, such a deformation is undesirable in general, and in particular in the walls of, say, a fast-breeder reactor. In the latter, the fluctuating level of the hot Sodium fuel drives thermal ratcheting. The aim is to ultimately develop a predictive design tool hopefully of use in an actual FBR.

Dynamics of non-ideally cantilevered beams: In a fast-breeder reactor, the nuclear fuel assembly consists of very many hexagonal rods held vertically by inserting one end into a cylindrical bearing. Because it is often necessary to take these rods out for cleaning, some clearance is maintained in the bearing. However, this clearance greatly influences the vibrations of these fuel rods.

The ultimate aim is to model the dynamical response of the fuel subassembly due to vertical and horizontal base excitation.

Simplified models for rolling: The need of the hour, for all people interested in toys, is a simplified model for rolling contact. Most famous toys, like the celt, the tippy-top, or the spinning egg cannot be explained by assuming idealized rolling. They require us to realize that two bodies cannot contact at only one point; there is a zone of contact, within which slipping necessarily takes place at most points. This slipping leads to a frictional moment. The extent of slipping and the magnitude of the frictional torque depend on the rolling speed, the local geometry and also the rigidity of the objects. This is a complicated relationship, as evinced by the presence of a tyre-modeling industry. I want to develop a simplified model that may be employed to gauge the mechanics underlying toys. We should not require recourse to complicated tyre models.