The influence of initial imperfections on the ultimate bearing capacity of super-large hyperbolic cooling towers

摘要

The uncontrollable factors such as construction error, material inhomogeneity, etc. will inevitably lead to a certain initial imperfection. This paper mainly studies the initial defects of cooling tower structure in the elastic-plastic stage influencing on the ultimate bearing capacity. Through elastic buckling analysis and the self-vibration characteristics of analysis, the buckling modes and the vibration modes multiplied by the modal contribution coefficients are introduced into the structure as the initial defects of hyperbolic cooling towers, taking into account nonlinear material under the premise of the modified arc-length method in order to amend the elastoplastic ultimate bearing capacity of the structure. In the end, the numerical results show that: the super-large hyperbolic cooling tower with vibration mode initial imperfections is more sensitive than with buckling mode initial imperfections; this method can efficiently search for the most unfavorable initial imperfection distribution form, so it can be applied to large-scale engineering structure initial imperfection analysis.