NASA Uses Shape Memory Alloys to Fold F-18 Aircraft Wing

Engineers from NASA  and Boeing have successfully used shape memory alloys (SMA) to move a full-sized wing section of an F/A-18 Hornet. This test is part of a project investigating the use of shape memory alloys to fold aircraft wings in flight for enhanced aircraft performance.

Transcript

00:00:00 >> Spanwise adaptive wing is about moving wing sections in flights to improve aircraft efficiency. Whether it's a drag reduction or control authority or better stability. We are not the first ones that's doing this. In fact, this dates back to the early 60s. Like the example of the XB-70. But what's different here and what's new is how do we fold those wings. At the heart of spanwise adaptive wing project,

00:00:25 we have this new multifunctional material known as shape memory alloys. Which change shape or remember different shapes as you heat them and cool them. And can be used as actuators. Recently back in, a few months back we did a flight test on a sub-scale aircraft using these new actuators. And, in fact, for the first time we used a new high-temperature shape memory alloys developed at NASA Glenn based on nickel-titanium hafnium.

00:00:52 And this new material had the right characteristics for flight. So now that we've done this flight test, we wanted to transition to a full-scale test. Being this F18 wing sections that we're demonstrating on. And with that we took the existing hardware of the folding mechanism. Which is a motor, electric motor. And the transmission, gear transmission. And we replaced that with a 5,000

00:01:17 and then a 20,000-inch pound torque-rated actuators based on the shape memory alloys. The first test condition is from zero to 90 degrees. So from horizontal to vertical. Similar to the way an F18 aircraft folds wing. In this case the highest torque is at zero. And then reduces as the wing section moves up. I should point out that it is controlled all the way. And we can dial any angle in this wing from zero to 90 with very good precision.

00:01:51 This next test condition is from minus 45 to 45 degrees. Since our project is not just about folding on the ground, but also in flights, we need to evaluate how folding the wing down looks like. Here the torque increases as we approach zero reference angle, so horizontal plane. And then decrease again as we reach the positive 45. In a real flight scenario, this is the kind of loading or kind of [inaudible] that you would expect. [ Music ]

00:02:30 >> This ground demonstration is one of a kind on multiple fronts. We'll have a new and improved shape memory alloys. High torque actuators. And new mechanisms. Our next goal is to take it to the next level. Learn what we've taken in ground testing and mature it into a full-scale, flight-ready actuation system. [ Music ]