Description: |
HOTSPOTTER is a finite element software package for evaluating the susceptibility of axisymmetric multidisk brakes and clutches to thermoelastic instability (TEI). An eigenvalue method is used to determine the exponential growth rate of eigenmodes of the system for a given rotational speed. The critical speed is then determined by searching for the lowest speed at which at least one mode has a positive growth rate. HotSpotter can be used as an aid in the design of transmission clutches and disk brakes against thermoelastic instability, which is believed to be significant source of material failure in clutches and of low frequency vibrations in brakes. Transient analysis of the problem involves a very small time increment for numerical stability and convergence and is therefore extremely computer-intensive. The HotSpotter algorithm uses the eigenvalue method which removes time from the governing equation. It also uses Fourier decomposition, which reduces the required finite element discretization to the cross sectional plane. These techniques greatly reduce computational time and increase numerical accuracy. |