Special time-histiry analysis problem!

[IgorDzuklevski]

Hello everybody. From Belgrade, Serbia.
This is my question:
I have to solve the problem below:

It is a concrete frame, where the concrete plate is subsituted with a frame section with great height. One of the diagonal frame elements is acting like a damper in the system, due to the area reducing 10cm from the constraint.
I need to put a time history analysis in SAP2000 (I own a 8.2.3 version) and response spectrum analysis, but I need to define a hysteresis curves for all the elements in the system.

How do I define hysteresis curves in SAP2000 for each element, and how do I define a velocity-time earthquake to the system????
Earthquake could be El Centro for example.

Thanks in advance.

 

[arigato]

Igor,


Using hinges is probbaly best way to define non-linear material behavior in a frame element other than defining link elements or a limiting load scenario in the elemnt. To define hysteris curves in frame SAP elements you need to define frame hinges first. If you to define>frame hinge property and click on define new hinge, you can modify what type of hysterisis curves you want easly for each individual force of the hinge such as moment and shear by typing in the values of the moment or shear and a corresponding deflection or rotation. Then all you have to do is click on your members with that will use these hinges and click on assign frame hinge and the name of the hinge you created. Check out the help option or the reference manual in PDF format that comes with the program to learn more about defining hinges. The online help isnt bad, but the PDF reference manual that coems with the program is much clearer as to whats going on in the program.

As for time history all you need to do is go to define > functions > time history> select: Define new function from file and click on: Add funtion from file and click on: browse to find the Time history file of your choice. Time histories can be gotten from sites like USGS. Beware that many sites give time history files in Sa/g and youll need to multiply the values by the g (gravity) you are interested in. This is easily done in SAP because now that you have a time history function, you can create an analysis case that uses your new time history and multiply it a scale factor of g like 9.81 if your working in meters. I havent tried playing with response functions so I cant help you there.

Good luck!