## 5 Concluding Remarks  
This paper presents results from medium-scale ice-crushing dynamics tests which were used to simulate _hpz_s with areas in the order of 10\({}^{3}\)-10\({}^{4}\) mm\({}^{2}\). The effect of ice temperature, interaction speed, indenter size and structural compliance on failure behaviour and associated structural dynamics have been studied and observed. The nature of the force-time curve was found to be highly correlated with observed failure behaviour which is influenced by competition between damage and fracture processes, in a manner similar to that described for small-scale tests. Several key findings emerged from these experiments:  
**Effect of Temperature:** Ice temperature was observed to play a significant role in failure behaviour. Colder ice failure was dominated by fracture with sharp peaks and large load drops resulting in increased dynamic activity and higher peak pressures. In contrast, warmer ice tends to exhibit smoother peak pressure profiles due to the dominance of continuous extrusion with intermittent spalling. **Interaction Speed:** Over the range of rates considered, the interaction speed did not have a significant effect on the magnitude of peak failure pressures. Rather, the interaction rate between ice and the structure was observed to primarily affect dynamic aspects of the interaction, with higher failure frequencies observed for faster tests. This highlights the importance of understanding the links between the drift speed and relative interaction rates for structures of different compliance levels in terms of their impact on dynamic aspects of ice-induced vibrations. **Indenter Size:** The well-established \"pressure-area\" effect was observed, with larger indenters generating higher total force, but lower overall levels of pressure as compared to smaller indenters. This effect is more pronounced in colder ice and when interacting with more compliant structures as was also reported in prior analysis. Structural Compliance: While peak pressures were found to be primarily influenced by ice-related processes, structural compliance was found to have a substantial impact on the failure frequency. It was observed that more compliant structures tend to extrude most of the damaged ice during each cycle, resulting in sawtooth-like interactions and the removal of much of the damaged ice beneath the indentation zone. This suggests that peak pressures are dominated by processes in the ice, while frequency is dominated by structural parameters and interaction conditions. The consistency of the reported observations from this study with prior small-scale indentation tests [20, 23, 24, 25] underscores the robustness of _hpx_ failure mechanisms across the different scales. Since _hpx_s are a fundamental component of the compressive ice failure process, the observed consistency of their failure behaviour on multiple scales is highly beneficial in guiding the development of models of dynamic ice-structure interaction processes. For many of the existing ice-structure interaction models [30, 31, 32], one of the primary difficulties lies in linking the model parameters with fundamental ice mechanics; however, incorporating the _hpx_ failure mechanisms can address this limitation. Recent models of non-simultaneous ice failure [33, 34] have been extended to account for the dynamic coupling effects described, providing promising new approaches for modelling dynamic ice-structure interaction processes of interest for offshore structure design. Conceptualization, R.H. and R.T.; methodology, R.H. and R.T.; formal analysis, R.H.; investigation, R.H. and R.T.; resources, R.T.; data curation, R.H.; writing--original draft preparation, R.H.; writing--review and editing, R.T.; visualization, R.H.; supervision, R.T.; project administration, R.T.; funding acquisition, R.T. All authors have read and agreed to the published version of the manuscript.