{"title":"Numerical modeling of beam plastic hinges in steel moment resisting frames including local buckling and stiffness/strength degradation","authors":"","doi":"10.1016/j.istruc.2024.107260","DOIUrl":null,"url":null,"abstract":"<div><p>Plastic hinge formation in beams is the main energy dissipation mechanism in moment resisting frames, but its deformation capacity is limited by the strength deterioration after reaching the maximum moment. Such degradation is highly influenced by the onset of local buckling in the plastic hinge region once a significant portion of the cross-section has reached the yield stress. Numerical models developed to study this effect have shown good accuracy against experimental data, but with high computational costs and the need to calibrate several model parameters. This work proposes a numerical model of a beam plastic hinge that uses only one parameter to reproduce the hysteretic behavior under cyclic loading, degrading simultaneously stiffness and resistance with lower computational cost. The proposed model relies on the discretization of the beam cross-section using uniaxial bars with a prescribed geometric imperfection with buckling degrading strength capability spanning along an assumed plastic hinge length. The Euler-Bernoulli hypothesis is imposed at the ends of the plastic hinge region and elastic beam elements are used to model the beam outside this domain. The model is validated against experimental data from three cyclic loading connection tests reported in the literature. Results show that the model can accurately represent the response of the beam plastic hinge with a low computational cost by adjusting one single model parameter as well as the definition of the nominal information of the beam geometry and material properties, expected plastic hinge length, and standard fabrication tolerances.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Structures","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352012424014127","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
引用次数: 0
Abstract
Plastic hinge formation in beams is the main energy dissipation mechanism in moment resisting frames, but its deformation capacity is limited by the strength deterioration after reaching the maximum moment. Such degradation is highly influenced by the onset of local buckling in the plastic hinge region once a significant portion of the cross-section has reached the yield stress. Numerical models developed to study this effect have shown good accuracy against experimental data, but with high computational costs and the need to calibrate several model parameters. This work proposes a numerical model of a beam plastic hinge that uses only one parameter to reproduce the hysteretic behavior under cyclic loading, degrading simultaneously stiffness and resistance with lower computational cost. The proposed model relies on the discretization of the beam cross-section using uniaxial bars with a prescribed geometric imperfection with buckling degrading strength capability spanning along an assumed plastic hinge length. The Euler-Bernoulli hypothesis is imposed at the ends of the plastic hinge region and elastic beam elements are used to model the beam outside this domain. The model is validated against experimental data from three cyclic loading connection tests reported in the literature. Results show that the model can accurately represent the response of the beam plastic hinge with a low computational cost by adjusting one single model parameter as well as the definition of the nominal information of the beam geometry and material properties, expected plastic hinge length, and standard fabrication tolerances.
期刊介绍:
Structures aims to publish internationally-leading research across the full breadth of structural engineering. Papers for Structures are particularly welcome in which high-quality research will benefit from wide readership of academics and practitioners such that not only high citation rates but also tangible industrial-related pathways to impact are achieved.