I am doing a Dynamic slug force calculation (Time History) where the slug force is 30KN. what made me doubtful about my results was that I spotted 66KN axial force on the fixed support in the tail end of the system at 4560ms however, once I checked the time fragments at 4500ms and 5000ms the axial forces were way less than 66KN and would happen in two different directions! I would like to know how come it is possible to have a response on a support even larger than twice of the slug force?

just a quick note: "reaction forces on different directions" was totally nonsense; I mistook the "spectrum direction" with force direction.

a

If you're still having issues with this, open a Support Request on Smart Support and send in your job files.

Richard,

I don't seem to have any issues with the software itself, it just looks really strange that the reaction force on the anchor support is even higher than twice the slug force.

This is unusual, but possible. The maximum DLF of 2.0 is (theoretically) the maximum ratio of the dynamic result to the static result for the single application of the event (which is assumed to be dominated by the response of a single mode).

A response spectrum or a time history analysis includes the response contribution of all of the systems modes.

A DLF of 2 is appropriate for a single, instantaneously applied load that does not change once started. In a hammer analysis, you may be applying your load on several elbows and these may be interacting with one another thus showing an effective DLF greater than 2. Also, in CAESAR II, the response due to mass participation above your frequency cutoff does not have the sign sense of the modal responses. That combination may also upset the DLF=2 relationship.