Ahmad,

I took a look at your dynamic input.

I find that the “time history” data supplied in both jobs were identical. It looks to me as if you ran your time v. load data through the DLF/Spectrum Generator (that tool button) rather than entering the data directly as a time v. load table. I believe you entered your time v. load data as “User Defined Time History Waveform” in the generator. Unfortunately, this processor converts the time history into a force response spectrum (you requested 25 frequencies up to 100 Hz). And these 25 frequency v. DLF data points were used as time v. load for the time history analysis.

Compare the “time histories” in each dynamic input echo. The maximum load defined is no more than 1.2582 “kN” at 1.67147 “milliseconds” in both jobs. (The generator created a dynamic load factor of 1.67147 for an oscillator tuned to 1.2582 Hz.)

The changing magnitude of the force set (1 kN to 81 kN) should modify the results but I won’t go there until this other matter is cleaned up.