New ASDCoupledHinge Model for Accounting PMM Interaction within Lumped Approaches for RC Elements скачать в хорошем качестве

New ASDCoupledHinge Model for Accounting PMM Interaction within Lumped Approaches for RC Elements

Non-linear analyses are essential for simulating the structural behavior of RC elements. The main approaches can be roughly divided into two categories: distributed plasticity and lumped plasticity. The former is typically combined with fiber-discretization of sections and has the big advantage to accounting inherently for interaction between axial force and bending moment (PMM interaction); on the contrary, it is quite difficult to include the effects of bond-slip in the sectional response; finally, more computational effort is necessary for this kind of models since the non-linear sectional response must be computed for a certain number of integration points within the element length. Lumped plasticity, on the other hand, is generally preferred for analysis of big structures and by practitioners due to the lower computational effort and simplicity of the modelling technique; furthermore, it has the advantage of making it easy to include effects of bond-slip; on the contrary, the main drawback of this approach is that in general, it does not account for PMM interaction. Some attempts based on plasticity are available in literature and in some software packages, even if the use of these models for RC elements is not consistently validated. ASDCoupledHinge is a new section model to be adopted in lumped plasticity approaches that permits to account for PMM interaction by means of section strength domains in the PMM space. The model is implemented in OpenSees and STKO and permits the user to define the strength domain and, to be as general as possible, to include user-defined equations for evaluating at each analysis step yield stiffness, cap- and post-cap rotations.