An ABAQUS simulation can include any number of steps.
An analysis step is a period of “time” during which the response of the model to a specified set of loads and boundary conditions is calculated. The character of this response is determined by the particular analysis procedure used during the step.
The response of a structure in a general analysis step may be either linear or nonlinear.
The starting condition for each general step is the ending condition of the previous general step. Thus, the model's response evolves during a sequence of general steps in a simulation.
Linear perturbation steps calculate the linear response of the structure to a perturbation load. The response is reported relative to the base state defined by the condition of the model at the end of the last general step.
In general steps the OP parameter on any loading options—such as *BOUNDARY, *CLOAD, and *DLOAD—controls how the values specified with these options interact with those values defined in previous steps.
Analyses can be restarted as long as a restart file is saved. Restart files can be used to continue an interrupted analysis or to add additional load history to the simulation.