Catenary action of restrained steel beam against progressive collapse of steel frameworks  

作　　者：李国强 王开强 刘玉姝 陈素文 

机构地区：[1]Department of Building Engineering,School of Civil Engineering,Tongji University [2]State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University [3]School of Civil Engineering,Wuhan University [4]China Construction 3rd Engineering Bureau Co.Ltd.

出　　处：《Journal of Central South University》2012年第2期537-546,共10页中南大学学报（英文版）

基　　金：Project(2006BAJ01B02)supported by the National Science and Technology Pillar Program during the Eleventh Five-Year Plan Period of China

摘　　要：The changing law of internal forces during the whole deformation development process was analyzed. The process was divided into five stages based on the internal force state of the beam and the assumptions of internal force relationship of five stages were proposed. Then, the formulas for determining the midspan deflection of the steel beam under distributed load, which was restrained both in rotational and axial directions, were obtained using restraint coefficient method and rigid-plastic mechanism, thereby the deformation development process was expressed accurately in a quantified way. Priority was given to the analysis of the process from bending to tension-bending, then the final state totally depends on tension to resist the external loads, that is the problem of catenary action of the restrained beam under distributed load. Additionally, finite element analysis was carried out with soitware ABAQUS6.7 on a restrained steel beam under distributed load with different axial and rotational restraint coefficients. The accuracy of the formulas presented was verified by the results of the behavior of the restrained beams. Finally, error analysis was conducted and some formulas were corrected according to the reasons of errors. The calculated results of corrected formulas match the FEM analysis results better, thus the accuracy of these formulas is improve .The changing law of internal forces during the whole deformation development process was analyzed. The process was divided into five stages based on the internal force state of the beam and the assumptions of internal force relationship of five stages were proposed. Then, the formulas for determining the midspan deflection of the steel beam under distributed load, which was restrained both in rotational and axial directions, were obtained using restraint coefficient method and rigid-plastic mechanism, thereby the deformation development process was expressed accurately in a quantified way. Priority was given to the analysis of the process from bending to tension-bending, then the final state totally depends on tension to resist the external loads, that is the problem of catenary action of the restrained beam under distributed load. Additionally, finite element analysis was carried out with software ABAQUS6.7 on a restrained steel beam under distributed load with different axial and rotational restraint coefficients. The accuracy of the formulas presented was verified by the results of the behavior of the restrained beams. Finally, error analysis was conducted and some formulas were corrected according to the reasons of errors. The calculated results of corrected formulas match the FEM analysis results better, thus the accuracy of these formulas is improved.

关 键 词：restrained steel beam catenary action rigid-plastic mechanism numerical analysis formula correction 

分 类 号：TU391[建筑科学—结构工程]