Drop test studies generate large amount of information due to the small time increments that the solver internally uses to calculate the response. To save on disk storage, the program does NOT save all results it computes. Instead, it gives you options to specify the number of equally spaced instants at which results are saved for all nodes as well as refined graphs at selected vertices and reference points. You can also specify the instant at which the program starts saving results.
The recommended approach is to start saving results from the moment of impact (t = 0) for the first run. If the generated graphs and plots indicate that no interesting events, like high stresses, took place until time t, you can rerun the study to get more refined results at the window of interest. The Time to start saving results and the Solution time after impact parameters define the period for which the program saves the results. The Number of plots and the Number of graph steps per plot determine the resolution of data saving.