static time history& push over different results

[khajehdehia]

dear friends
the lab test for energy dissipative steel device is performed the lab test results is existed , I analyze the model on time with static time history analysis (the load is displacement with maximum value of 20cm ) and the analytical and experimental result is coincided the maximum load is 2o kn and yield strength is 15 kn but when I analyze the a fore mentioned device with the same property through push over analysis (applied load is 20cm displacement) firstly, it encountered to grater force than 20 kn secondly it doesn't yield at 15kn force it yields at grater values also the displacement correspondence to 20kn force is lower than corresponding one in static time history analysis in hysteresis curve while I think they must be the same especially the yielding strength must be equal at two case, how can I over come this problem?

[Stelios_Antoniou]

It is not totally clear from your description but I would guess that you are applying in pushover displacement incremental loads with load control. Change that and apply force incremental loads with response control. This might fix the behaviour. Applying displacements in MDOF systems typically fixes the deformations to a predefined pattern and gives wrong results

Stelios Antoniou
SeismoSoft Developer