ICE-INDUCED VIBRATIONS OF OFFSHORE STRUCTURES

Abstract

Level ice acting on vertically sided structures may cause damage due to the considerable ice load and structural ice-induced vibrations. However, the existing models are usually validated for very limited cases and give largely discrepant predictions with measurements. In this study, a new physical mechanism is proposed that can explain the interaction between level ice and vertically sided structures, based on which, a new phenomenological model is developed that can give more accurate predictions and applicable to rigid and compliant structures with different scales, at a wide range of ice indentation velocities. The capability of the model is achieved by three components considered. The strain-rate dependent stress-strain relationship, the randomness in ice failure length and the spatial correlation of failure lengths. A set of quantitative criteria for identifying different ice-induced vibration modes are developed, which helps better assess the capability of the developed model for capturing different vibration modes.