structural steel
structural steel
Hi, I'm a new PhD student and I'm currently doing nonlinear analysis of steel structures and I would like to look at the response at a range of amplitudes, from very high, design earthquake / ultimate level amplitudes down to not-so-high, working stress level amplitudes. From what I've read, the model that is most appropriate for main steel members (i.e. not rebars) is the classic stl_bl. While I'm sure the bilinear+kinematic hardening model is sufficient for earthquake level amplitudes, I do not think that at around working stress levels (just below yield point), steel material behaviour is still purely linear which stl_bl suggests. Or I maybe wrong. So anyway I ask this stupid question: Can I really not use the other models for structural steel?
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kalmithkush
- Posts: 8
- Joined: 07 Jul 2010, 12:24
Re: structural steel
Dear Ronjie,
Yes, I agree with you that material does not behave purely linear just below the yield point. If you have a look on the past experimental test data of structural steel either on monolithic or cyclic loading, then, you can note that there is a transaction curve between the initial and post-yield stiffness. So, if you are interested in taking into account this effect especially around working stress level, I strongly suggest you to use Menegotto-Pinto steel model(-stl_mp) in which you can define the shape of the transaction curve. Furthermore, I suggest you to use the Menegotto-Pinto steel model-stl_mp as a uniaxial material model for structural steel members to properly take into account to Baushinger effects together with isotropic and kinematic hardening for all the types of loading conditions including the earthquake loading.
Kushan
Yes, I agree with you that material does not behave purely linear just below the yield point. If you have a look on the past experimental test data of structural steel either on monolithic or cyclic loading, then, you can note that there is a transaction curve between the initial and post-yield stiffness. So, if you are interested in taking into account this effect especially around working stress level, I strongly suggest you to use Menegotto-Pinto steel model(-stl_mp) in which you can define the shape of the transaction curve. Furthermore, I suggest you to use the Menegotto-Pinto steel model-stl_mp as a uniaxial material model for structural steel members to properly take into account to Baushinger effects together with isotropic and kinematic hardening for all the types of loading conditions including the earthquake loading.
Kushan