Size effect simulations on compression-torsion failure of concrete-filled steel tube columns
Under the action of earthquake,concrete-filled steel tube(CFST)columns are prone to compression-torsion failure due to torsion and the torque action will aggravate the destruction of CFST column.In this paper,a mechanical analysis model and numerical simulation method for CFST columns are established,which can take into account both the concrete heterogeneous characteristics and the concrete/steel tube contact behavior,and then the failure behavior and size effect of CFST columns under the combined action of compression and torsion are simulated and studied.The effect of structural size,axial compression ratio,steel ratio and section shape on failure mode,nominal torsional strength and size effect behavior of CFST columns are analyzed.The results show that:With the increase of axial compression ratio,the torsional capacity of the CFST column first increases and then decreases,and the torsional capacity of the member reaches the maximum value when the axial compression ratio is about 0.4.The size effect of CFST columns under compression and torsion is found to a certain extent;according to the simulated working conditions in this paper,the nominal torsional strength decreases by 24％;in addition,with the increase of axial compression ratio,the size effect of nominal torsional strength of members decreases first and then increases.Based on the numerical test data of this paper and the author's previous work,a formula for size effect of nominal torsional strength of CFST columns considering the influence of axial compression ratio and steel content is proposed.
万方数据
维普
