Research On Failure Evaluation Method Of Highrise Frame Core Tube Structure Based On Overall Stability

With the continuous increase in the height of the structure now,the aspect ratio of the structure is getting bigger and bigger,and the structure is getting higher and more flexible.When the aspect ratio is getting bigger and bigger,the structure often collapses due to the overall instability,so the overall Stability is an important feature that cannot be ignored in high-rise structures.The essential reason for the overall instability of high-rise structures is the continuous increase of the additional overturning moment of the structure caused by the second-order effect of gravity.At present,the existing research mainly analyzes the overall stability of the structure based on the elastic deformation of the structure,and rarely involves the nonlinear stage.Therefore,this paper considers the change of the overturning moment of the structure in the plastic phase,based on the overturning moment and the anti-overturning moment,puts forward the index of the stability region,finds out the critical instability state of the structure,and evaluates the overall stability of the high-rise structure.Specific research work as follows:Derivation of the overturning moment formula for high-rise structures based on the second-order effect of gravity.The high-rise structure is assumed to be a vertical cantilever rod model.On the basis of considering the effect of the structure’s own weight on the horizontal bending deformation,the additional effect on the horizontal shear deformation is further considered,and the high-rise structure is deduced in the elastic and plastic stages.The overturning moment formula determines the number of iterations,clarifies the relationship between the overturning moment and the structural parameters such as the height,dead weight,and lateral stiffness of the structure,and studies the relationship between the lateral bending stiffness and the shear stiffness of the structure and their relationship.The relationship between the structural aspect ratio,total displacement angle determines the expression of overturning moment in the bottom of the structure.Numerical verification of overturning moment of high-rise frame core tube structure.By establishing regular high-rise frame core tube structure models with different aspect ratios,and performing horizontal pushover analysis on them,the law of the overturning moment along the structural height of the high-rise frame core tube structure in the elastic and plastic phases is obtained,and the previous theory is passed.The comparison of the analyzed overturning moment verifies the rationality of the deduced overturning moment formula,and the error caused by it is analyzed.Research on anti-overturning moment of high-rise frame core tube structure.Based on the high-rise frame core tube structure system,the influence of different factors such as aspect ratio and displacement angle on the structure’s anti-overturning ability is studied,and the bearing capacity of the bottom of the structure is studied.The change law of the bottom bending moment and base shear force of the inner core tube structure;and introduce the force degradation mechanism of the bottom column members of the structure,study the anti-overturning moment law of the structure,and determine the expression of the anti-overturning moment and the relationship between the anti-overturning moment and the structure’s own parameters Relationship.High-rise structure failure evaluation index based on stability region.Combined with previous research,based on the overturning moment and anti-overturning moment of the high-rise structure,the stability region index is proposed to evaluate the overall stability of the high-rise structure,clarify the critical state of structural instability and collapse,and divide the different failure stages of the structure;The dynamic elasto-plastic analysis of the frame core tube structure simulates the earthquake action,which verifies the correctness of the index for the evaluation method of the overall stability of the high-rise structure.