Plastic hinges

[lee7]

Hi,

I have a few question about the seismostruc.

Type of structure: Steel
Bays : 3@6m
Storey : 4
Tool : Pushover analysis


I try to check the plastic hinges for my stucture. What i know, the moment is going to decrease with height of the building. So, the plastic hinges should occurred at 1st level, unfortunately, its occured at 3 level and followed by another level.

Im using strong column - weak beam method.

1. How can i check the value of moment for each beam.

2. I set the material strain with a default value 0.020. So its going to notify every time it higher than 0.020. So during the analysis, for example its notify me by starting with bmx3144,bmx3141 and till finish. So i assume that, the first plastic hinge occured at bmx3144 followed by others. It is right way to check it?

Thank you.

[seismosoft]

Hi,

1) The procedure is described in the Help System of the program.

2) It is not clear to us what do you mean by "set the material strain with a default value of 0.02". Do you mean that you set a strain-based Performance Criteria check using a 0.02 threshold value? If yes, then the procedure is indeed correct. However, are you sure a steel strain of 0.02 is indicative of plastic-hinge formation? To us it seems 10-times higher than expected (but these are in any case technical matters that are not necessarily related to the software, so we leave it up to you).

SeismoSoft Support

[Teddy Susanto]

Hello, I'm the new user of SeismoStruct. Previously, I used Ruaumoko 3D, ETABS, or SAP2000 to carry out Nonlinear Pushover analysis and Nonlinear Time History Analysis. In Ruaumoko 3D, I can obtain damage index in the frame element. Otherwise, using ETABS or SAP2000, I can obtain plastic hinges location. If I use SeismoStruct, can I obtain plastic hinges location in the frame element or damage index?

Thank you very much,


Teddy Susanto

[seismosoft]

Hi,

As discussed both above and in the Help System of the program, you need only to check the steel strain values (e.g. by setting appropriate Performance Criteria) to know if hinging is taking place or not (it is recalled that hinging takes placed once the steel has yielded)

Seismosoft Support