Compressive capacity of perforated tubular members using symbolic regression of DoE-FEM simulations

Offshore steel tubular structures may be subjected to damage perforations by long-term operation in a corrosive environment, which reduces their structural strength. There is a lack of standards and procedures to quantify the loss of structural capacity in view of the damage dimension and geometrical and material characteristics of the tubular member. The present paper proposes the use of symbolic regression for assessing the remaining capacity of perforated steel tubular members from aged offshore units subjected to axial compressive forces. A Finite Element Analysis campaign was generated in combination with a full factorial design of experiments. Length-to-diameter, diameter-to-thickness and damage extension ratios have been addressed as potential preponderant factors for the experimental design. Results from numerical simulations were statistically evaluated and then symbolic regression was handled to generate an optimized expression by minimizing the worst error case between predicted and numerical results. Capacity responses from the generated expression lie close to the Finite Element Analysis and experimental results, suggesting that the proposed methodology can be alternatively employed to assess the remaining capacity of perforated steel tubular members subjected to axial compressive loads.