Description: The specific class of problems motivating the enhancements to the steady-state transport analysis procedure and the symmetric model generation technique involves thermo-mechanical analysis of a disc brake system in the automotive industry. Disc brakes operate by pressing a set of brake pads against a rotating disc. The friction between the pads and the disc causes deceleration. The severe temperature changes due to frictional contact as well as mechanical loading cause inelastic deformation and circumferential tensile stress in the disc, which may eventually lead to the failure of the disc. Hence, the prediction of fatigue and failure of a disc brake system is fundamental in assessing product performance.

The traditional way of analyzing this type of problem is to use a Lagrangian approach in which the disc rotates relative to the brake assembly, which is pressed against the disc with contact and friction. Since many revolutions are typically required to reach the state of interest to the analyst, this approach is prohibitively expensive and cumbersome. With the use of the steady-state transport analysis procedure, the Eulerian method in which the finite element mesh of the disc does not rotate relative to the brake assembly but the material “flows” through the mesh provides a cost-effective alternative approach. The paths that the material points follow through the mesh are referred to as streamlines. This kinematic description converts the moving disc brake problem into a pure spatially dependent simulation.

The steady-state transport procedure allows the steady-state solutions to be obtained directly or by using a quasi-steady-state (pass-by-pass) technique. You can choose a set of elements in a model to be described in an Eulerian manner; the rest of the elements in the model are treated in the classical Lagrangian manner.

Most material models that describe mechanical behavior are available for use in a steady-state transport analysis. In particular, history-dependent viscoelasticity, classical metal plasticity, rate-dependent yield, rate-dependent creep, and two-layer viscoplasticity can be used in a steady-state transport analysis.

The steady-state transport analysis can be the only step, can follow a general or linear perturbation step, or can be followed by a natural frequency extraction step or a complex eigenvalue extraction step. Multiple steady-state transport analysis steps can be included in a single analysis. Restart of a steady-state transport analysis is also supported.

The three-dimensional model used in a steady-state transport analysis must be generated using the symmetric model generation technique. A periodic three-dimensional model, such as a vented disc, can now be generated by revolving a three-dimensional repetitive sector about a symmetry axis using the symmetric model generation technique. Other enhancements include support for heat transfer and coupled temperature-displacement elements used with the symmetric model generation and symmetric results transfer techniques.