| Abstract | Based on understandings of the mechanisms that constitute ice-spallation phenomena, gleaned from various ice-crushing lab tests conducted at NRC, it was determined that it should be possible to incorporate low-profile textural patterns/components into the design of a structure's faces that could disrupt the spalling process. This was confirmed in earlier small-scale lab tests that showed that during ice crushing when using NRC's Blade Runners technology (Patent US 9,181,670 B2), instead of a series of large-amplitude spallation-induced sawtooth load spikes, a considerably greater number of much smaller ice spallations, and associated load-spikes, were produced due to the textured surface's ability to initiate spallation. While the average load in that case basically remained the same with or without the surface technology, the amplitude of the sawteeth load spikes was greatly reduced. Consequently, due to the invariance of ice properties in the brittle regime over a wide range of scale, the Blade Runners technology has the potential capability to reduce the amplitude of the sawtooth load pattern that develops due to repetitive ice spallations that occur when a moving ice sheet crushes against an offshore platform, such as a wind turbine or oil/environmental-monitoring platform. Here, we present a new technology that uses an essential aspect of the physics underlying the earlier Blade Runners technology, i.e., spallation initiation/disruption, but uses it in a manner requiring less surface modification than the former technology stipulates, to not only reduce the amplitude of the spallation-induced sawtooth load pattern, but also to reduce the average ice load. Data from lab tests using the new technology are discussed. |
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