Overview

The fixed step option is available for the GSTIFF integrator supporting both the I3 and SI2 formulations and for the HHT integrator. The purpose of the fixed step option is to ensure that a fixed amount of work is completed in a given time to satisfy the requirements for a real time operating system (RTOS). This is achieved by limiting the number of Newton steps in the implicit solve (that is, number of iterations per Adams Solver integration step) to ensure a fixed amount of work is performed.

This option can be employed regardless of the environment; that is, it can be used also in non-RTOS scenario, for example, to help determine ahead of time if a given analysis can be suitable for real time simulation and if the results will be acceptable.