PSI - Issue 59

Alfiy Alfatarizqi et al. / Procedia Structural Integrity 59 (2024) 420 – 427 A. Alfatarizqi et al. / Structural Integrity Procedia 00 (2024) 000 – 000

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2. Ultimate Strength of Cylindrical Structures Steel-reinforced cylinders are widely used in floating offshore structures, including semi-submersibles, platform tension legs, submarines, and offshore wind turbine foundations. These structures, serviced by supply vessels and exposed to ship traffic, must be designed for strength and safety against collisions, damage, and buckling. The key concern is assessing the ultimate residual strength after collisions to ensure safe operation. Accurate prediction of residual strength is crucial for decision-making on whether the structural system can continue operating or requires a halt. (Li & Kim, 2022).

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Fig. 1. Failure of wind turbine tower (a) (Ebert, 2023), (b) (Ruskin, 2016).

Figure 1 illustrates the failure modes of a wind turbine tower, emphasizing the necessity for a numerical investigation to evaluate the ultimate strength of cylindrical structures. This analysis aids in modeling various geometries, loads, and boundary conditions, predicting potential failures, and identifying design weaknesses before actual failures occur. Cylindrical structure failures pose risks such as hazardous material leaks, structural damage, economic impact, production disruption, and environmental consequences. 3. Single loading 3.1. Axial force Axial force is a force that acts along the longitudinal axis of an object, such as a rod or structural element. Axial forces can act parallelly, either as tensile forces (pulling away from the axis) or compressive forces (pushing towards the axis). Reference to axial forces is based on Hooke's law for elastic materials, where stress and strain have a linear relationship. = (1) Cylindrical structures reinforced with binding supports (stringers) combined with ring stiffeners are designed to provide orthogonal reinforcement against axial pressure and hydrostatic pressure. These reinforced cylinders may experience damage when subjected to impact loads, such as ship collisions, mass impacts, and severe collisions, where ship collisions can potentially result in significant damage. In a previous study conducted by O. Ifayefunmi in 2016,