vertical collapse

[wuhaoshrek]

Hi, all,

I have been using fiber beam-column elements to represent a RC shear wall structure. The analyze is dynamic with incremental intensities of ground motion. A lean-on column was connected to wall elements to consider gravity loads and further the P-delta effects. In the wall sectional modeling, besides cyclic degradation considered in the concrete material model, I accounted for the fracture of reinforcing steel by incorporating "MinMax" material model to the regular steel02 model in OpenSees.

For some ground motion, I could observe wall collapse vertically through the animation (some nodes literally displaced significantly in the vertical direction). Is is a possible phenomenon? Thx.

[fmk]

with the model chosen it is indeed a posible modeling outcome.

[wuhaoshrek]

Hi, Dr frank,
Yes, I was actually hoping it happen. I noted the collapse initiated at a certain node, above which that portion of the model would collapse vertically. When I checked out the sectional response (M-phi, N-eps) of the element connecting that certain node, I couldn't find a reason that cause the collapse of that part. This is the part that confuses me. So I was wondering if the program is giving a unreasonable result due to numerical issue around that period, or is there any other explanations that you may provide? Thank you.

[fmk]

look at the section responses.

[wuhaoshrek]

Hi, Frank,
I have created a new material with DLL file. But when I copy the file to my laptop (both win7 64bit), it doesn't work. I remember the same problem happened when i start to use my current office computer, I did rebuild the new material, but when I try to rebuild this time, it failed. I even could't rebuild it again in my office computer (failed with the example ElasticPPCPP as well, following the demo). Do you have any sense what happened then? much thanks.

[fmk]

if the dll fails it is probably due to code files in developer directory not being in agreement with what was built into the .exe. each revision of the app these days is needing the core files be updated. you need to downloda the files corresponding to the revision number.

if using svn you need to change opensees.berkeley.edu to peera.berkeley.edu