Physical mechanism of ice-structure interaction

Ji, Xu and Oterkus, Erkan (2018) Physical mechanism of ice-structure interaction. Journal of Glaciology, 64 (244). pp. 197-207.

[img]
Preview
Text (Ji-Oterkus-JG-2018-Physical-mechanism-of-ice-structure-interaction)
Ji_Oterkus_JG_2018_Physical_mechanism_of_ice_structure_interaction.pdf
Accepted Author Manuscript
License: Creative Commons Attribution-NonCommercial 4.0 logo

Download (2MB)| Preview

    Abstract

    To obtain the effect of velocity and structural natural frequency (structural stiffness) on ice failure, an extended dynamic Van der Pol based single degree-of-freedom ice-structure interaction model is developed. Three basic modes of response were reproduced: intermittent crushing, frequency lock-in and continuous crushing. Further analysis on physical mechanism of ice-structure interaction is presented on the basis of feedback mechanism and energy mechanism, respectively. Internal effect and external effect from ice and structure were both explained in the feedback branch. Based on reproduced results, energy exchanges at different configurations are computed from the energy conservation using the first law of thermodynamics. A general conclusion on the predominant type of vibration when the ice velocity increases during the interaction process is forced, self-excited and forced in each three modes of responses. Ice force variations also shows that there is more impulse energy during the lock-in range. Moreover, ice-induced vibration (IIV) demonstrates an analogy of friction-induced self-excited vibration. Finally, the similarity between strain-stress curve and Stribeck curve shows that static and kinetic friction force variations are attributed to ice force characteristic, and can be used to explain the lower effective pressure magnitude during continuous crushing than the peak pressure during intermittent crushing.