Determination of the Worst Imperfection in Framed Structures
DOI:
https://doi.org/10.70567/mc.v42.ocsid8562Keywords:
Steel Structures, stability, imperfections, buckling modesAbstract
Current structural analysis codes specify that structures must be analyzed considering the presence of imperfections in their geometry—that is, deviations from the ideal or perfect geometry defined in the design. These standards also state that the imperfection causing the greatest destabilizing effect must be considered; however, they do not propose criteria for identifying it. This work presents a methodology for calculating the worst imperfection in a structure composed of beams and columns. It is well known that the shape of the worst imperfection is associated with the first buckling modes, and particularly, if the first critical load is sufficiently separated from the second, then the worst imperfection corresponds to the first buckling mode. This is typically the case for most frame structures. An efficient iterative method is then proposed to find the first two buckling modes in order to verify that the first mode indeed represents the worst imperfection.
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