Generalized plasticity model for inelastic RCFT column response

Nonlinear analysis of circular double-skin concrete-filled steel tubular columns under axial compression

“…The behavior of conventional circular CFST columns has been studied analytically and numerically by researchers [7,9,10,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Kostic et al [37] developed a concentrated plasticity beam-column model based on the generalized plasticity material model for CFST beam-columns. The axial force and bending moment interaction, gradual yielding and strain hardening of material and nonlinear geometry under large displacements were taken into account in the model.…”

Minkowski plasticity in 3D frames: Decoupled construction of the cross‐section yield surface and efficient stress update strategy

“…This is the reason why this strategy is not commonly employed in practical contexts. The second approach formulates the cross‐section yield criterion in terms of generalized stresses, that is, axial force and bending moments . This is, therefore, more useful from an engineering point of view, being theoretically able to provide synthetic results in an extremely short time, and also making it possible to afford parametric studies on the design parameters.…”

“…Due to the small iterative effort, the approach also compares well with specialized direct methods for limit analysis, with the advantage of providing the load‐displacement relationship. The geometric nonlinearity under large displacements can be accounted for by means of corotational formulations . The geometric interpretation of the Minkowski sum together with the proposed analysis procedures opens, however, new attractive possibilities to account for the strength decrease due to damage or fire exposition without the need to reconstruct the yield surface.…”

“…The second approach formulates the cross-section yield criterion in terms of generalized stresses, that is, axial force and bending moments. 2,[8][9][10] This is, therefore, more useful from an engineering point of view, being theoretically able to provide synthetic results in an extremely short time, and also making it possible to afford parametric studies on the design parameters. However, the accurate and efficient evaluation of the yield surfaces of steel or RC sections under axial force and biaxial bending as well as their use in elastoplastic analysis is not an easily resolved problem.…”

“…The geometric nonlinearity under large displacements can be accounted for by means of corotational formulations. 10,44 The geometric interpretation of the Minkowski sum together with the proposed analysis procedures opens, however, new attractive possibilities to account for the strength decrease due to damage 9 or fire exposition 45,46 without the need to reconstruct the yield surface. The proposed approach, in fact, allows us to obtain the new yield surface by simply contracting the ellipsoid of each cross-section region accounting for its strength reduction.…”