AC40 will experience big changes!
by SEAD DEDOVIC | VIEW 1674
Emirates Team New Zealand is already focusing on the development of the AC40 after the accident they had on Tuesday. The LEQ12 team had an accident. Key people will find the solution "The first things we look at in this type of dynamic event are the accelerations and rotation rates that come from yacht's inertial measurement unit (IMU)," Jamie Timms, Emirates Team New Zealand Structural Engineer said, as quoted by sail-world.com "These readings allow us to infer the magnitude of the hydrodynamic loads on the hull structure, which we can then input into our structural simulations to estimate the stress state and structural margins of safety.
We also use the data to validate our fluid dynamics simulations of high velocity hull impacts." "During the 36th America's Cup, we captured and catalogued the dynamics of every major event across the three yachts we sailed in that campaign and we enveloped those, with additional margin, to define the load cases for the AC40.
Over the first 18 days of sailing the AC40, we'd seen a couple of events that generated large impacts. These had been lining up with our design load cases and the hull structure was performing as expected. However, this latest event saw accelerations that were far beyond all our previous records."
The team of experts immediately determined what the problem was, and will now work on it.
Things like this shouldn't happen to them anymore, but it's all part of the sport. "The figures above compare the longitudinal and lateral decelerations from the AC40 crash against the largest event seen by Te Rehutai, the team's AC75 from the last America's Cup.
"Not only did we see longitudinal decelerations 70% higher than the previous worst-case, but this was coupled with a simultaneous lateral loading of similar magnitude - the yacht came to a complete stop and yawed 90 degrees in just over a second.
We believe it was this combined load state that led to an initial failure of the foredeck sandwich panel. The damage we saw in the hull and partial detachment of the bow structure is likely a consequence of the compromised deck panel, rather than a root cause."