tfosterwsu
Structural
- Oct 29, 2012
- 1
I'm modeling a 6 story building that I hope to verify against actual test data.
All preliminary tests are conclusive but I am unable to include dead load within my time-history analysis. My base reaction (Z) for static dead load case is 810kips. My base reaction (Z) for my time-history acceleration load case is 0.165 kips.
I'm running a time-history function of base accelerations using non-linear, direct integration and p-delta. My time integration method is Hibler-Hughes- Taylor with an Alpha factor of -0.33. Mass and stiffness proportional damping is 0.5%. I've run nearly all related parameters and still cannot get my time-history acceleration load case to show any significant change in Base Reaction (Z).
I've done runs with:
Load Pattern self-weight multiplier is set for 1.0 or 0 on the two load cases (Dead and ACC)
Frame gravity multiplier set to 1.0 or 0 on both Load Patterns
I've done all combinations of these runs to no avail as well as defining mass source to the load patterns.
I have also given my Dead load case a non linear direct integration function and applied it with my Acceleration Case. Once again, I cannot activate the dead load in my acceleration cases.
Could I be reading the output Base Reactions table wrong? Dead Load, according to the table, is spot on (within a few hundred pounds of the actual test building).
Any advise/insight would be greatly appreciated!
Thanks
Tyler
All preliminary tests are conclusive but I am unable to include dead load within my time-history analysis. My base reaction (Z) for static dead load case is 810kips. My base reaction (Z) for my time-history acceleration load case is 0.165 kips.
I'm running a time-history function of base accelerations using non-linear, direct integration and p-delta. My time integration method is Hibler-Hughes- Taylor with an Alpha factor of -0.33. Mass and stiffness proportional damping is 0.5%. I've run nearly all related parameters and still cannot get my time-history acceleration load case to show any significant change in Base Reaction (Z).
I've done runs with:
Load Pattern self-weight multiplier is set for 1.0 or 0 on the two load cases (Dead and ACC)
Frame gravity multiplier set to 1.0 or 0 on both Load Patterns
I've done all combinations of these runs to no avail as well as defining mass source to the load patterns.
I have also given my Dead load case a non linear direct integration function and applied it with my Acceleration Case. Once again, I cannot activate the dead load in my acceleration cases.
Could I be reading the output Base Reactions table wrong? Dead Load, according to the table, is spot on (within a few hundred pounds of the actual test building).
Any advise/insight would be greatly appreciated!
Thanks
Tyler