Research On Fire Performance Of Restrained PEC Columns Based On Sub-structure Model (Around The Weak Axis)

The research on the fire performance of PEC column is still in the primary stage at home and abroad.However,as part of the structure,PEC columns are subject to the constraints of adjacent components,there is a certain difference on the performance of fire with a separate column.In order to reflect the fire resistance of the restrained PEC columns in real structure,the substructure contained with segmental beams and columns was employed in this paper,which can take the axial and rotational restraint,and the continuity of the end of columns into consideration.Specific content as follows:(1)Select restrained partial encased concrete columns based on the actual local fire conditions.(2)By using the software ABAQUS,a sequentially coupled thermal-mechanical analysis model was established to calculate the axial deformation curves and fire resistance of the sub-structure including partial beams,retrained PEC columns and concrete floor slab.The model was validated by using the fire resistance test of PEC column.(3)The temperature field and mechanical response analysis was conducted using the validated model of the PEC axial compression column and PEC eccentric compression column.(4)The effects of load ratio,axial restraint stiffness,retrained beam span,beam load,slenderness of column on the fire performance of the PEC axial compression column were studied based on coefficient of axial force change and the axial displacement curve.(5)The effects of load ratio,axial restraint stiffness,retrained beam span,beam load,slenderness of column and eccentric ratio on the bending fire performance around the weak axis of the PEC eccentric compression column were studied based on coefficient of axial force change and the axial displacement curve.(6)Analysis the behavior of the sub-structure subjected to axial load and eccentric load under fire condition,including influence of load ratio under fire strength on the mechanical behavior and the fire resistance limit...