Disabling discontinuity handling in submodels

SIGFXA01 It is not possible to disable the discontinuity handling at simulation level. Simcenter Amesim standard solver always handles discontinuities. However, some submodels can optionally disable their own discontinuity handling mechanism. This is normally done through an enumeration parameter “discontinuity handling” which value can be either “active” or “inactive”, as in the following example from SIGFXA01.

Figure 10: SIGFXA01 parameters

Disabling discontinuity handling can help in case of linear interpolation applied to a table containing a huge number of points with few changes in the slope of the curve. This is typically the case of a cam profile: the profile is usually very smooth, and sampled every degree of half degree. Interpolation

Figure 11: linear interpolation of tabulated data

The 2 curves represent linear interpolation of tabulated data. The curve on the left with a saw tooth profile contains sharp variations of slopes between 2 consecutive intervals. In this case, activating the discontinuity handling is mandatory to get correct simulation results.

On the other hand, the curve on the right shows a smooth slope variation. Disabling the discontinuity handling should not harm the simulation.

There are not quantitative criteria for deciding whether discontinuity handling can or cannot be disabled. It is the responsibility of the user to decide to disable it when submodels offer such an option.