Numerical study of the effects of flange damage on the steel beam capacity under static and fatigue flexural loads

Steel structural sections can get damaged owing to several factors, including natural and operational factors. This damage affects both the structural element's resistance to external static loads and the number of load cycles in fatigue loading. The impact of this damage depends on the percentage, location, and the type of stress applied. Damaged steel I-beams were studied in the lower flange and under static loads only. In this study, a finite element (FE) simulation is performed to investigate the effect of damage on the upper and lower flanges of steel I-beams and the effect on the maximum flexural load capacity and number of load cycles. The maximum flexural load capacity was measured with the shape of the stress distribution through the cross-section at the location of the damage. For validation, the obtained FE analysis results are compared with those of six steel beam specimens from previously published experimental tests. The results demonstrate that numerical analysis can accurately simulate these elements. Moreover, the maximum flexural capacity is unaffected when the damage to the lower beam flange is less than 20%. The location of any percentage of damage to the upper flange directly affects the efficiency of the beam. The damage has a greater impact on the number of load cycles than on the maximum flexural load capacity. The load cycles decreased by 90.5%, with 40% damage on the lower beam flange. Thus, the effect of the stress concentration should be considered when calculating the number of load cycles.