Podcast: Sandro Di Natale, HBK


In this month’s podcast I’m talking to Sandro Di Natale, product and application manager from test and measurement company HBK.

Sandro works on static and fatigue testing, wind tunnel testing and iron bird testing in both the aviation and space sectors. His clients include companies like Airbus, IABG, Dynetics, Embraer, Lockheed Martin, and Gulfstream.

Sandro has some really interesting insights during that talk about integration between virtual and physical testing and how software can really complement validation phases in tests. He also has lots of enthusiasm for the aviation sector!

Sandro is also speaking at the Aerospace Testing Symposium in London on the 29th and 30th of September, which is co-located with the London to Sydney: The future of aviation conference.

For more information about those events or to register go to symposium.aerospacetestinginternational.com or email anna.young@markallengroup.com


Ben Sampson 0:00
Hello, Sandra, thanks for spending some time with me. And could you start a little bit by telling me about HBK? And what you do and how you work with your aerospace clients?

Sandro Di Natale 0:13
Yeah, thanks, Ben, for this opportunity HBK is quite new company, so to say, but we have a long history. So we came out of a merger a few years ago from the old Bruel and Kjaer and HBM, Hottinger Baldwin Messtechnik. A Danish and a German company.
So the German part is from 1950, the Danish part even older from the 30s. Basically, if we think of an aircraft, we are working on a lot of parts there in different applications. But maybe we come to the different applications a little bit later. And start with more the structural, as this is my core discipline. And the other applications are not, not so much my focus, so to say.
So basically, if you think of a structure, it goes from coupon testing, starting from coupon testing, material testing, learning more about the material, qualifying materials, could be composites could be metals, could also be new manufacturing methods like additive manufacturing, because you also need to qualify the same material, but manufactured in a different way. All the way up to the most interesting ones, the most interesting tests, which are the certification tests, like static load test of a wing with 1000s of measurement channels, 1000s of strain gauges, and let’s say it’s brother, the full scale fatigue test, again, you have the whole, or almost the whole aircraft could be smaller ones, business jets, but could also be the big commercial airliners, like Boeing’s, Airbus, and so on. And what we do there is we try to supply as much from the measurement chain as possible. So that starts from simulation software.
So you have an FCM model, you have static load cases, and we’re able to convert that into simulating real load. So load which an aircraft or a component for an aircraft, it’s actually not possible to simulate the whole airframe, but one component level, you have the simulated loads, which, from experience, try to represent the lifetime, or the loads that an aircraft will encounter in its life. And try to understand, okay, where are the weak part? Where do we later in real testing, because real testing is really expensive? So we really need to focus? Where do we put sensors on? Where do we need to learn more? Where do we have critical points in the structure and so on.
So we have that simulation part. And from there, we go to the sensors, typically in the structural, static and fatigue testing, that would be strain gauges, but maybe also forced transducers, or other sensors, to the data acquisition hardware and software. And finally, you have the data acquired, you need to understand what does that mean? Yeah, yeah. Take out the information and analyze the data.

Ben Sampson 3:17
How long has the company been offering simulation for?

Sandro Di Natale 3:38
So I can rather speak for the HBM part of the company because that’s where I come from in the HBK family. Actually, that was an acquisition that HBM took around, I believe it’s, it was before I joined, but I believe it was in 2008 2009 timeframe. So 12,13 years ago, I’ve already expanded our portfolio from what you say, being a classical data acquisition sensor data acquisition company towards more into the software direction. I mean, it’s, I believe, it’s a no brainer, software will or is becoming has become more important and will become more important in the future. Because testing as I said, testing time is expensive, and it takes a lot of time. So, people are the engineers start to try to simulate as much as possible of course,

Ben Sampson 4:30
When do you become involved with your client’s projects? Is it best to be involved very early on in the design phase or do you come in a little bit late in the testing or?

Sandro Di Natale 4:49
Yeah, you cannot say that in general. It depends of course, when we enter so depending whether we are considered for simulation, then we would enter quite early. I’m more a data acquisition guy. So I have deeper insight there. But yeah, it depends, you can enter quite early on material coupon or component level, or at a later stage when prototypes are already built big prototypes, and then you enter more on the on the full scale that before the static or fatigue tests.

Ben Sampson 5:24
Okay. Can you just talk through some of your customers, what they come to you for, what are the kind of common challenges that people come to you with at the moment?

Sandro Di Natale 5:40
So one, very, very critical thing, and I would it down, I would give it three exclamation marks, one thing is always time. Because time is money, and people need to go to market as soon as possible, we were seeing quite some delays at the moment in the big commercial airliner programs. And this costs billions of euros or pounds, if you wish. And you need to think that every week every day, is very, very expensive, where you just have one prototype, and you need to have that certification before you’re allowed to really go into air before you’re allowed to ship that product. So that is the most pressing factor, I would say is really time.
Another aspect is, if you think of what I said in the beginning, composite materials, new manufacturing processes, pushing things closer to the limit to be more efficient, in terms of performance, reducing weight, and so on. This means that our customers need to deeper insights, maybe 50 years ago, people would not care too much about the kerosene consumption of an aircraft, because flying was really a luxury, and people would pay any price. So it was not so important. Today, it’s completely different. We are flying around the world. So we are pushing things more to the limits, not only in structural testing. Therefore, we need deeper insights. And we believe we’re an open company.
We do not say that you can, or you should only use our equipment for testing. Of course, we love if you use our equipment for testing, but you’re able to combine it with different ways of testing, for example, stereoscopic cameras, which gives you a whole different insight compared to punctual sensors, like strain gauges, which gives you an excellent result on that point. But if you want to get the big picture of a wing, for example, the ideal thing is to combine these to have the macroscopic view of the whole wing, but also the details, the critical points, which you cannot get with the resolution of a camera.
And another aspect is which we are which we have seen for quite some time. But we are obviously still seeing a lot in Europe is multinational projects. It’s important. We had a nice project with Lockheed Martin and BAE systems quite some years ago, which was a transcontinental project, actually. So tests were done in the US and in the UK at the same time, and people needed to share data.
And if we think of a company like Airbus, it’s a European company, you have them in the UK, for example, in fields, you have them in Hamburg, you have them in Toulouse, and they need to cooperate, they really need to work together and our products, our solutions make that possible, both on the testing side during the test, as well as before test in the simulation with a clever data management and analysis. Okay, so these are a few. I mean, they have a lot of challenges, of course, but these are few, which come to my mind.

Ben Sampson 8:51
And you mentioned the tool chain earlier on. Could you just define that for me? Are you including all of the simulation tools and all of the kind of physical tools that an engineer has at his disposal?

Sandro Di Natale 9:06
Yep. So we think we provide the whole tool chain for testing and data acquisition. So we’re not a testing company, like there are others maybe you know, IBG, close to Munich, they have done a lot of testing for Airbus. Basically, they tested I believe, every Airbus since 1972, the 300, the 320, and so on. We’re not a service provider, we’re a solution or product provider.
And if we think of the tool chain, I defined it as a tool chain for structural fatigue testing. And that starts from simulation tools. As I said, we are not a CAD company, or an FEM solver company, but if you have that CAD data, the geometries and the load the static loads, we can convert that into a virtual fatigue test of components. So that’s where our tool chain would start.
And from there going to the real the physical test, including the sensors, strain gauges, including the data acquisition hardware and software to make sure that all data is acquired. And at or during the test already shared with a different people, design engineers analysis engineers. And later when it goes to deep dive evaluation, which is still a little bit separated, but obviously will be more growing together in terms of, we have a password, which we use for that script analytics, do it will roll more and more together, it will be more life analysis. We also offer that with powerful data management tools, to again, we have big teams working on that they can collaborate, they can share data.
And at the moment, we’re really bringing some new stuff in terms of calculation speed, we just have a nice example again, from IBG, we were working close together with them. For a customer of theirs, an aircraft manufacturer, they had to record 180,000 flight cycles in the fatigue test, you can imagine that’s a lot of data. And to perform really powerful calculations, and really leverage the power that your pc or even server system has. This gives you a big advantage because it really reduces calculations maybe from half an hour, a few years ago to a few minutes or even seconds. And this is where we see our tool chain, we’re not into the test rig and so on other players in the market, but this is where we define from test to report or from simulation to report.

Ben Sampson 11:44
Well, I’m just interested, where do you see the innovation at the moment? Is it more within the hardware or more of in the software?

Sandro Di Natale 11:53
I would see, I would say, the easy answer, it’s more in the software, because sorry, for using the buzzwords like artificial intelligence and machine learning, but bringing that more into concrete aspects like understanding patterns to understand if I have a certain load, how is my strain or stress response, evolving over time understanding that automatically, we cannot we cannot assess this this as humans, because we cannot imagine hundreds of thousands of data points.
One example really of artificial intelligence, we see that it’s very important and will be even more important in the next years. Again, the test engineers, the analysis, engineers get more insights from the test.
But nevertheless, some people might say that the hardware for acquiring strain gauges or other sensors is, at the end, it’s not true. We still see ways to improve accuracy of data, or reduce uncertainty of data, make the setup process, for example, more efficient, quicker, more failsafe and so on, really to support the test engineers who do the preparation to make to be more efficient and reduce time. But you’re of course, right. When we’ve had what? 70 years of data acquisition hardware. You’ll never know, I don’t know if there will be a disruptive event in the next years. If I knew that I would be really, really glad. But I still see quite some room for improvement.

Ben Sampson 13:36
And of course, the way that the software and the simulation software itself integrates with the hardware with the data acquisition equipment is quite important, isn’t it?

Sandro Di Natale 13:51
Exactly. This is what I meant with this stream analytics. So, the traditional way would be that you that you have data files, it’s still not traditional, it’s still the normal way today, I would say mostly, you have data files, bigger or smaller doesn’t matter, then you take this file and do the analysis in the future. And this obviously, influences hardware and software. This needs to grow more together that you really do some from a data stream directly, maybe not the full, fully evaluated or fully sophisticated analysis. But you already start understanding to some extent, live during the test to adapt your test, adapt your simulation, and do that, that loop to really get a result.
Change the simulation, understand things better, better, maybe change the test adapter, test adapter load introduction, and get better results. So this is exactly right. What you’re saying then, they need to grow together. And this pulls requirements on hardware and software.

Ben Sampson 14:58
All right. So being integrated would suggest that perhaps test engineers need to work across the organization with other departments. I mean, is that is that something you agree with? And something HBK can help facilitate?

Sandro Di Natale 15:20
Yeah, I think so. I mean, products should not be designed for testing. Yeah. Okay. So for us, maybe as a as a data acquisition testing company, that would be great. Products should be designed for performance, efficiency, and so on.
But if you already consider that, and there are tools to do that, something we have in our program is the so called Virtual strain gauge, where you can already see okay, where do I need to position that. So if you if you consider that as early as possible, it will pay off later. Because the testing is necessary. You need to certify to qualify. The the authorities FAA iasa, in Europe, they do not rely on pure simulation, maybe on component level to some extent, but not for a full scale for peak test, it’s still a full scale for the test and not a simulation. So if you consider that it will pay off to some extent, again, in saving time during the test, I believe.

Ben Sampson 16:20
OK so could you just tell me a little bit about what the most interesting part of how you work the client? What’s the most interesting application you’ve come across so far?

Sandro Di Natale 16:39
Yeah, so, um, that’s diffiuclt. It’s hard to judge. Unfortunately, at the moment visiting customers is really hard to do. But from a size perspective, I was in the hall where the A380 went through the full scale fatigue test, the biggest aircraft ever built, these passenger aircraft, and I’m too young.
So today, I have been there during the test of the A380. But I was in the hall when there was, was a small business airliner and the A220. And you saw that during the full scale for test its still impressive, because when you stand in front of that big, yeah, but you see that hall where the A380 is vast, and it seems like a toy. Because the hall is so big, and there are two aircraft there.
Yeah, it’s hard to translate that in words. But if that in front of an aircraft is still big, maybe seats, I don’t know, 80 people, but it’s very small compared to the other ones. And then if you go in other directions, wind tunnel testing is always really impressive. Because it’s really small scale, you cannot put a whole aircraft in a wind tunnel would be really incredibly expensive to have that airflow in that size.
So you have a tiny model, maybe one to 10, or even less. But the interesting thing, and it was something I mean, you know it if you think about it, but I had to somehow learn, if you scaled down the volume by one to 10. In each dimension, it scales down one to 1000 in terms of force, and so on and drag. So this pulls puts a lot of requirements on the on the on the accuracy of the data acquisition system. Yeah, basically, you need to be 1000 times more accurate compared to the what, what full scale model? So these are these are two examples.

Ben Sampson 18:53
When you’re talking about something as large as that aircraft, like the A380, or the 220. And then the part that HBK is helping with it’s quite small, right? Ot’s a different scale. But important?

Sandro Di Natale 19:10
We all know that in the test and measurement world, that is not only true for us at HBK. But for other companies too. We’re a niche market. We’re not a 500 billion euros mass market. I don’t know like smartphones, we know we’re in the niche, but that niche is important.
Because if you if you look at the full scale fatigue test, if you look at the static test of an aircraft wing or a wind tunnel test or something like when electrical systems are tested. When you sit on an aircraft you rely on that. You need to be sure that the wing when it bends, I don’t know two meters high, doesn’t have anything and if you know how it is tested, you know that it’s absolutely not an issue because it might have been tested to the I don’t know, four or five, five times this, this deflection.
And it is, it is a small role, if you look at the whole project of developing and building a new aircraft, but as many others, it’s not just us, but it’s a crucial role, I believe, because it gives safety, it gives just a good feeling. When you hop on an aircraft, and you know, every single everything was third certified, well, I can trust that it is working, and we will not just fall off the sky.

Ben Sampson 20:33
Okay, so let’s finish up now. I mean, what can we what can we expect from HBK? And how do you think things are going to change in the next kind of three, four years?

Sandro Di Natale 20:47
Yeah, so this is really related to what I’ve been saying to some extent already. We believe that also within HBK, a way to grow more together, and even have a stronger link from that simulation part over data acquisition to analysis. Because we see that it might sound a little bit at this, this, I don’t know the English word perspective, I’m not sure if that’s an English, but we see a new generation, a different generation of people of young age is younger than I am maybe the 20s. They come more from the PC side from the simulation side, and maybe you need to convince them that you still need a test. So we need to bring this together. To have it really integrated to understand, okay, simulation test. Both is very important. And you get the most out of your work, when you are able to combine that as good as possible.

Ben Sampson 21:50
Yeah, because we always come to the same point, I often discuss this to people that validation is always going to be necessary, right?

Sandro Di Natale 21:59
Absolutely, absolutely. And, and if you start from the from the other side, a simulation doesn’t fall off and you cannot use a textbook to get an Youngs modulus, if you use material, which is a proprietary for your company. So on that actually, I would see tests even increasing because the material structures are getting more complex, you need more for the for the simulation, you need the input from somewhere. Yeah, as I said, the Youngs modulus doesn’t fall off, you need to determine it. And if you make a big mistake there, let’s say 10%, your simulation will be at least 10% wrong. So, it’s really a mix and match between data, real data and simulated results simulated data as well.

Ben Sampson 22:48
Good. Okay, I think that’s a good place to finish. Sandro. Thanks. Yeah. It’s it’s really good to speak to you.

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About Author


Ben has worked as a journalist and editor, covering technology, engineering and industry for the last 20 years. Initially writing about subjects from nuclear submarines to autonomous cars to future design and manufacturing technologies, he was editor of a leading UK-based engineering magazine before becoming editor of Aerospace Testing in 2017.

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