Nominal moment capacity of partially deteriorated AISC W-section beams

In this paper, a new dimensionless section property named WSSR (W-Section Sensitivity Ratio) is proposed and used as a relative indicator of the sensitivity of the section to the loss of its moment of inertia due to the loss of part of its flange area. A new term is introduced for partially deteriorated beams named “equivalent yield moment”. Consequently, a parametric study was conducted using a numerical finite element model calibrated using experimental test results in order to correlate the WSSR to the loss in the nominal flexural capacity. Moreover, a new design (code independent) nominal capacity chart is generated to accurately determine the “equivalent yield moment” and corresponding deflection of the partially deteriorated steel girders using the deterioration in sectional inertia and the deterioration length along the beam.