Learning Forum

[Baloch]

Hello every,

I am wondering to find out what APDL command can be use to to change the stiffness and damping of a longitudnal spring over time, Lets say I have a longitudnal spring connecting two members in a building and I want to change the stiffness and damping values of the spring over time lets say at 0.01 sec damping and stiffness should be A and B respectively while at 0.02 C and D and so on.

Best regards

[peteroznewman]

Adding this as background for anyone who may have a suggestion.
You wrote about viscous dampers in your other discussion:
/forum/discussion/33253/any-one-can-help-what-mistake-i-am-doing-for-time-history-analysis-of-a-rcc-structure
and the Focus.pdf shows this graph of Force vs Displacement which occurs over a time when oscillations occur.
Here is the equation as a function of frequency f, displacement x, and temperature T:

[Baloch]

Actually yes I am using a spring for viscous damper but my question is not about this pdf. I want to use a longitudinal spring as viscous damper and want to change its properties stiffnss and damping over time. What is the best way to do it? By a apdl command? or a macro script? or any other way?
best regards

[Baloch]

Have you got what I exactly mean? If so, do you have how it can be possible to control the damping and stiffness of the longitudinal spring over time? e.g the damping and stiffness shown in the figure from the properties table of the longitudinal spring and I want these two values should vary over time (should change at each time step of my earthquake loading).