Cervenka Consulting Forums — cyclic load of concrete shear wall

Re: cyclic load of concrete shear wall

null@example.com (alexandru_fabian) — Wed, 12 Jan 2011 06:13:42 +0000

Your assumptions are right with the difference that I didnâ€™t use an elastic plate on the displacement application point. I will use your recommendations and inform you about the obtained results.
Thank you for your answer.

Re: cyclic load of concrete shear wall

null@example.com (dpryl) — Tue, 11 Jan 2011 15:27:50 +0000

Hello, without seeing your model I can only guess... I assume you load by prescribed displacements and that you have point load applied through an elastic loading plate (more precisely, 2 plates - each from one side). I assume the supports are defined in Load case 1, and the two directions of the load are defined in LC's 2 and 3 (e.g., negative Z displ. to the top plate in LC 2 and positive Z displ. to the bottom plate in LC 3).

Then, the load steps for 1 cycle can look like this:

1. loading
n steps with LC's 1 and 2, positive multiplier

2. unloading
n steps with LC's 1 and 2, negative multiplier

3. loading to the other side
m steps with LC's 1 and 3, positive multiplier

4. unloading
m steps with LC's 1 and 3, negative multiplier

Anyway, do not forget do define monitoring points for all quantities of interest, at least the displacements and reactions both loading points.

If you still have problems, send us your model along with your ATENA user number (WR). If possible, include a sketch and/or photo of the real setup you are modelling.

cyclic load of concrete shear wall

null@example.com (alexandru_fabian) — Tue, 11 Jan 2011 14:46:17 +0000

Hi,
I've already read the some posts about cyclic loading in ATENA. My problem is quite the same with the one of userâ€™s DIRA called cyclic load model by DIRA with last post in 2010-01-11 17:25:07 by dpryl.
Iâ€™ve tried to model the cyclic model first loading in one direction, then unloading to 0 from the same side and loading to the other side. I saw the recommendation to always apply compression (unloading from the other side to avoid severe cracking of concrete) but in this case the unloading doesnâ€™t occur. In the response of the user DIRA to you it seems that the problem was resolved. Can you explain me how should I apply the loads from both sides with the unloading of the element during the cycles?
Thank you,