simdesign.rcmrf.bnsm.cp01.column

This module provides the column class implementation for the CP01 model in the BNSM layer.

class simdesign.rcmrf.bnsm.cp01.column.Column(design, bondslip_factor, capacity_design, load_factors, cyclic_model=False, cracked=None, yield_mom_curv='empirical')[source]

Bases: ColumnBase

Column implementation for the CP01 model.

The column is modeled using a concentrated plasticity approach. Plastic rotations are concentrated at the element ends via beamIntegration('ConcentratedPlasticity', ...) (end hinge integration points with an elastic interior region), while the element formulation is provided by ColumnBase.

End-hinge flexural behaviour about the local z-axis (Mz) is defined using a uniaxial Hysteretic material, expressed in terms of bending moment vs. chord rotation of the whole member (the yield rotation includes the elastic deformations). The elastic interior is therefore nearly rigid in flexure (STIFF_INTERIOR_FACTOR), and the springs carry the whole flexural flexibility.

If there is no capacity design, degrading shear springs are defined using the uniaxial LimitState material coupled with a ThreePoint limitCurve (drift-based), following the strength and post-peak degradation formulations adopted from Elwood & Moehle (2003) and Sezen & Moehle (2004).