Numerical and Experimental Analyses of Steel Tubular Members with Oblong Perforations Subjected to Compressive Load

In offshore steel tubular structures corrosion caused by the environment can lead to perforations that compromise their integrity. However, there are still no well-established standards for assessing the reduction in structural capacity considering the damage dimensions. This article aims to investigate, both experimentally and numerically, the strength of tubular structures with oblong perforations under compressive loads, as well as to propose the use of regression to estimate the remaining load capacity. In the experimental analysis, four tubular members with varying length-to-diameter and diameter-to-thickness ratios are used, featuring oblong perforations oriented longitudinally and transversely. A finite element model is also developed using shell elements, and the experimental and numerical results are compared, with the four tested samples being replicated with identical geometry and stress–strain material curves. The numerical model results demonstrate remarkable agreement with the experimental findings, particularly regarding the maximum axial load capacity, validating its applicability to similar configurations. Based on the results, regression was employed to generate an optimized expression, minimizing the error between the predicted values and the numerical data. It is concluded that the size of the perforation in the transverse direction of the tubular element is critical to the loss of compressive strength, whereas the perforation length in the longitudinal direction contributes significantly less.