Local ice pressures for semi-submersible in ice regions: Impact analysis of the high-pressure zone distribution

• The varying distribution of high pressure zones represent the influence on ice non-simultaneous failure. • The occurrence moment and location of the local extreme ice pressure are compared at different ice failure. • The spatial distribution number and width of high pressure zones are clarified. • The impact on semi-submersible platform at different high pressure zones distribution is compared. During the process of ice crushing failure, an uneven distribution of pressure emerges as a distinctive phenomenon. The attributes of high-pressure zones (HPZs) are pivotal in influencing the ice-resistance design of semi-submersible platform columns. Through laboratory-scale experiments, tactile sensors were employed to capture local ice pressure data, elucidating the distribution patterns of localized pressures during interactions between ice sheets and vertical structures. This study investigates the relationship between localized extreme ice pressures and global peak ice forces, alongside the spatial characteristics of HPZs at instances of peak global ice forces. The experimental findings reveal that extreme local ice pressures coincide with the moments of global peak ice forces across varying ice velocities; however, their occurrence frequency differs markedly between high and low velocities. HPZs corresponding to peak global ice forces predominantly appear at approximately 0.34 times the ice thickness from the central axis. In nearly 90% of the test cases, only one or two HPZs were observed at the moment of peak global ice forces. Building on these experimental insights, a method for estimating extreme local ice pressures was formulated. This framework, combined with the experimentally derived HPZ distribution characteristics, informed finite element simulations of a semi-submersible platform column subjected to ice loading. Comparative analyses of structural responses, with and without incorporating HPZ effects, underscore their significance. Notably, neglecting HPZs results in underestimations of maximum von Mises stress by as much as 130%. Moreover, variations in HPZ positioning induce structural response differences of nearly an order of magnitude. These findings underscore the necessity of integrating localized ice pressure effects and their distribution patterns into the ice-resistance performance evaluations of Arctic semi-submersible platforms.