When using THA - Time History Analysis it is a common question from RM Bridge users how to include acceleration and velocity in the dynamic analysis report. Though velocity and acceleration are not primary results, but intermediate calculation values. Therefore, they are not output in the standard list file. However, the action TInt also produces a .csv file in addition to the standard list file, and velocities and accelerations are stored there in addition to the displacements for all points specified in the RMSet.
Note that the accelerations used in the time-stepping procedure are often mathematically relaxed or over-relaxed, such that the integration procedure is stable and displacement values are as accurate as possible. So, velocity and acceleration values externally recalculated from displacements are usually more accurate than the mathematical values used in the integration scheme. Therefore, we recommend entering the time development of displacements into a column of an Excel sheet and recalculating the average velocities of the time steps from these displacements and average accelerations from these velocities.
Therefore, the best answer to the question "How can I obtain the variation in time of the velocity and acceleration in some nodes of the deck when using Time History analysis?" is to recalculate the values for accurate assessment; especially for acceleration values, it is recommended to recalculate them from the displacements instead of using these internal calculation values