钢-木组合柱抗火性能分析研究OA

Steel-timber composite columns are a new type of prefabricated component that is green,low-carbon,and highly efficient in load-bearing.However,research on their fire resistance perfor-mance remains notably limited.Numerical analysis methods were employed to investigate the fire re-sistance performance of steel-timber composite columns.Firstly,a numerical analysis model for the fire resistance performance of steel-timber composite columns considering thermal coupling effects was established.The accuracy of the numerical model was then verified using fire test data.Subse-quently,based on the validated numerical analysis model,the fire resistance performance of steel-tim-ber composite columns was simulated.Their axial displacement,fire-induced failure mode,and fire re-sistance were revealed and compared with those of pure steel(timber)columns.Finally,parameter analysis was conducted to investigate the effects of timber density,moisture content,encasing timber thickness,and steel ratio on the fire resistance of steel-timber composite columns.The results indicat-ed that for composite columns with low load ratios,axial deformation was dominated by thermal ex-pansion,whereas for those with high load ratios,axial deformation was dominated by compressive de-formation.There were mainly two failure modes of axially loaded steel-timber composite columns un-der fire conditions.Short columns with small slenderness ratios primarily underwent strength failure,while long and slender columns with large slenderness ratios both experienced overall buckling failure.The load ratio and slenderness ratio significantly influenced the fire resistance of steel-timber compos-ite columns.Timber density,moisture content,encasing timber thickness,and steel ratio also had a significant impact on the fire resistance of steel-timber composite columns,but their influence trends differed between short and long columns.In addition,the fire resistance of steel-timber composite col-umns exceeded that of pure steel(timber)columns,and the smaller the load ratio,the greater the in-crease in the fire resistance of the steel-timber composite columns.