2026-04-14T06:20:48Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/1827992026-02-07T01:18:30Zcom_2072_1033col_2072_452949

00925njm 22002777a 4500 dc Christos, Sofianos author Koumousis, Vlasis author 2013 In this work a beam element based on the finite element method, suitable for the inelastic dynamic analysis of structures is presented. The hysteretic beam element proposed by Triantafyllou and Koumousis [1] is extended to account for stiffness degradation, strength deterioration and pinching phenomena. The behavior of the element is governed by the BoucWen model of hysteresis while stiffness and strength degradation are based on Baber and Wen model [2] and pinching on Foliente’s model [3]. The case of non-symmetrical yielding, important for concrete members, is also taken into account. The proposed formulation is based on additional hysteretic degrees of freedom which herein are considered as hysteretic curvatures and hysteretic axial deformations of the crosssections. The elements are assembled using the direct stiffness method to determine the mass and viscous damping matrices, as well as the elastic stiffness and the hysteretic matrix of the structure. The entire set of governing equations of the structure is solved simultaneously. This consists of the linear global equations of motion and the nonlinear local constitutive evolutionary equations for every element. The system is converted into a state space form and the numerical solution is obtained implementing a variable-order solver based on numerical differentiation formulas (NDFs). In this way linearization at the global structural level is avoided facilitating considerably the solution. Furthermore, degradation phenomena are easily controlled through the model parameters at the element level and not in a macroscopic way which requires a computationally demanding bookkeeping mechanism. Numerical results are presented that validate the proposed formulation and verify its computational efficiency as compared to the standard elastoplastic finite element method and existing experimental data. Àrees temàtiques de la UPC::Matemàtiques i estadística::Anàlisi numèrica::Mètodes en elements finits Finite element method Plasticity -- Mathematical models Plasticity Degrading elastoplastic models, hysteretic beam element Elements finits, Mètode dels Plasticitat -- Models matemàtics Plasticitat Hysteretic beam element with degrading bouc-wen models