Colloquia

Summary

The application of composites in the hulls of high-speed crafts is gaining traction, yet concerns remain about their long-term durability against low-velocity ice impacts. This study experimentally constructs the E-N curve, which tracks the number of impacts until penetration for various impact energy levels, for two material lay-ups:  a carbon fiber composite and a composite with an additional protective glass fiber layer.  Testing was conducted using a drop weight impact tower and a custom-built setup designed for high-frequency, low-energy impacts. The integration of both test setups yielded complementary results. Additionally, residual stiffness and strength were assessed across various energy levels and impact frequencies. The simultaneous occurrence of different failure modes resulted in complex failure mechanics. Based on the findings, two key design recommendations were made for composite vessels subjected to low-energy impacts. First, while a sacrificial layer is beneficial for mitigating high-energy impacts, it offers limited advantage for low-energy impacts. Second, low-energy impacts cause significantly larger damage areas at the same damage fraction compared to high-energy impacts, leading to reduced structural strength. The findings contribute to the safe design of high-speed craft hulls in ice conditions. These insights can guide designers and engineers in enhancing vessel durability and performance, ultimately supporting more sustainable marine operations.