Smooth curve in pushover analysis

[Ana Santos]

Hi everyone,

I am doing a pushover analysis in a frame that have connections with a particular cyclic behaviour. I modelled the connection behaviour with a smooth curve... my question is if it is possible to use a smooth curve in a pushover analysis or if its is better to adopted just the monotonic part with a plastic behaviour, for example?

thank you

[fakharifar_mostafa]

I am not so sure about your question on "if its is better to adopted just the monotonic part with a plastic behaviour", but the answer to your question is dependent on your model and your desirable analysis results. If you have used link elements at beam-column joints to include the smooth curve in your numerical model, while doing pushover analysis, you may not see the effect of link elements forces. That would be a good idea indeed to make a similar frame model when no link element at beam-column joints are used and do the pushover analysis and compare the results from the two aforesaid models. Please bear in mind that fiber based elements with distributed plasticity take into account the deterioration, rather than just forcing the plastification into the so-called plastic hinge region in lumped plasticity approach. One may consult with the abundant existing literature in the context of earthquake engineering to choose a modeling procedure. For RC buildings joints (i.e., beam-column connection), if your frame is RC of course, you can refer to Prof. STEFANO PAMPANIN works. Specifically, the below references:
Pampanin, S., Magenes, G. and Carr, A.J. "Modeling of Shear Hinge Mechanism in Poorly Detailed RC Beam/Column Joints", fib Symposium on Concrete Structures in Seismic Regions, Athens, paper n. 171, 2002.
Pampanin, S., Moratti, M. and Calvi, G.M. "Seismic Behaviour of R.C. Beam-Column Joints Designed for Gravity Loads", 12th European Conference on Earthquake Engineering, London, paper n. 726, 2002.