The Finite Element Method 101 – Podcast with Engineered Mind

Few weeks ago, I did this podcast with Jousef Murad who has a great Youtube Channel “Engineered Mind”.

As you know, I am a fan of every engineer willing to put some time to teach others engineers about the beautiful world of FEA, Maths and Engineering in general, and that’s exactly what Jousef is doing.

Check out his Youtube Channel Engineered Mind here.

Here’s the video of the discussion I had with Jousef:

In this video, we are talking about:

• Why engineers need FEA?
• Is the FEA software really the most important?
• How to start learning FEA
• The difference between CAD and CAE
• What you can really simulate with FEA
• The main barriers to do FEA

I hope you like it this podcast as it is packed with extremely useful tips about FEA

If you are on YouTube, make sure to subscribe to Jousef’s channel, Engineered Mind, I really recommend it!

If you have comments about what we discussed or ideas of topics that would interest you, let me know in the comments!

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Transcript of the video:

Jousef:

Hi, and welcome to the Engineered Mind Podcast, a podcast about engineering, AI, neuroscience, and other interesting topics of life to educate and inspire people all around the world. I’m your host Jousef, and for this podcast I welcome Cyprien Rusu. Cyprien is a French engineer who loves to share his burning passion about the Finite Element Method, to help engineers all over the world. He has been using FEA for more than 10 years now, and he would like to change the way FEA is taught, in order to make it more accessible to engineers and designers, who really needed to improve their products. With his blog FEA For All, he’s creating content and FEA courses for everyone interested in learning FEA. And now ladies and gentlemen, happy learning with Cyprien Rusu.

Jousef:

Okay Cyprien, thanks a lot for accepting my invite for this spontaneous podcast. So, what we will start with is just give us an introduction to yourself, and what you do, and who you are.

Cyprien Rusu:

Well, thanks to you first to invite me to do this podcast. You know, I’m always glad to discuss with other engineers, and really this is a great opportunity to share knowledge about engineering, FEA, and a lot of stuff. As I saw that, you are also doing a lot of great stuff in this area. But like you said, let me introduce myself a bit for the people who don’t know me already. I’m currently Director of Engineering Asia in OnScale, a company doing cloud simulation. But I’m mostly known right now for my blog FEA For All, in which I teach engineers to become really good in FEA and to go basically from basics to an advanced level. Because there is a lot of crap going on in the area, and I’m trying basically to skim all this, to teach people in simple way, good practices, things to do, and really how to understand and how to do the right stuff. So, this is something that I do on my blog. I have a YouTube channel that I’m also doing for lots of years and posting a lot of videos, tutorials, all this stuff.

Cyprien Rusu:

And about myself, well you can say I’m an engineer and I think it’s obvious, right? I fell in love with FEA since I went into engineering school in France, in the École Centrale de Lille. Since, I never stopped to simulate all kinds of application, all kinds of physics of systems. I’m always amazed of what you can do with simulation and FEA, and I just try to teach as much as I can, what I know to all the people, that’s why I have this blog and this YouTube channel, and all the things I’m doing.

Cyprien Rusu:

And besides all that, I love learning languages. I can currently speak six languages, including Korean, Chinese, Japanese, a bit of German, but really a bit. English and French, which is my first language. Some people say that I have some kind of talents for language, but I don’t like this term, we can talk about that. Besides that, I like a lot of things, photography for example, or a lot of other stuff. So, I think that’s a view of more or less what I’ve been doing. Let me know if you have questions.

Jousef:

Yeah, that’s great. That’s great. What made you stick with FEA? Why not, for instance CFD, although it’s almost the same we can say. But what made you stick with FEA? What fascinates you?

Cyprien Rusu:

Well, FEA and CFD are two different things. CFD is basically computational fluid dynamics, right? So it’s a number of methods which can be based on FEA as well. Because you can use FEA or which means for those who don’t know what FEA means, it means finite element analysis. Right. So it’s based basically on FEM, which is a finite element method, and CFD can also be based on finite elements or finite difference. So, there are several methods. So I didn’t really choose between FEA or CFD. I’m doing both actually. If you look at my blog I have some teachers about that as well, just depends on my mood, let’s say.

Jousef:

I see.

Cyprien Rusu:

When I want to do some CFD, I do some, some CFD as well. It really depends on what I have on hand and what I want to teach people.

Jousef:

Can you walk us a little bit through your career path? Like where you started after you graduated.

Cyprien Rusu:

Yeah, sure. So, I did a double degree in France and in China and after that. After I finished my degree in the Qinghua University in Beijing, I went to work for MIDAS IT, which is you can say a medium small company in Korea, like 500 people developing query and simulation software. Those are software which are also based on the FEA, mainly for civil engineering in geo-technical. So at the beginning, I was doing geo-technical simulation and analysis, and then I went to mechanical. And what’s happened is that they were just developing this software called MIDAS, which was a pretty generalist software for mechanical simulation, including CFD, including a lot of stuff, and they had no one in the international team to handle this, and to basically help this business. So that’s when they just asked me, “Cyprien, do you want to do that?”

Cyprien Rusu:

I was a bit fool, but I was young, I took this opportunity, I said, “Okay, let’s do it.” And they gave me the software but the software was in beta, and there was basically nothing going with it. All the tutorials were in Korean. The presentation of other software were in Korean as well. They gave me a video of one of their VP speaking in Korean about the software. And they basically told me, “Okay, listen to this video and try to understand what he’s saying.” And I was like, “Okay, let’s start like that.” I started by looking at the Korean interface and the English interface to try to understand all what all those features meant. And really, I just graduated. I already had some experience about FEA that I had done in school or in university, trying to do some projects and stuff like that with other Abaqus.

Cyprien Rusu:

I thought that I knew a lot about FEA, but when you’re young you tend to think, “Okay I know a lot.” And then that’s when you’re basically crushed by the world and you realize that you know nothing, and you have to start from zero to learn again all this stuff. So I went through the software. I had to learn because this is very generalist software. So there was everything into it, all simulation, linear, nonlinear, dynamic frequency based, explicit, fast dynamic and CFD. And all of that was pretty new for me. I had done a bit of linear, a bit of nonlinear static, but that was all. And they just gave me a software and said, “Okay Cyprien, you have to make all the training materials, you have to train people over in the world. You have to find us some partners everywhere in the world.” So I had to start from scratch, to go all over all their stuff. And it was hard at the beginning, but it was really a really fascinating experience.

Cyprien Rusu:

It was a Korean company, so everyone was speaking Korean. I was an international team, so they were a bit more Anglicized, but still I had to, that’s why my Korean became much better after that. I was the guy who basically had to, let’s say market, and I started with the technical stuff, but really I switched to business very quickly because they needed some guy to do this kind stuff. And they basically put me in charge of the team, to spread the software in the world. So I had to do all the advertising, I had to do all the marketing, all the sales. I was doing the phone calls to the people. And, I was doing webinars all the time. Like, we have two webinars per week. So one month I had around 10 webinars per month to give. So I think, in four years I did something like 300, 400 webinars.

Jousef:

That’s crazy.

Cyprien Rusu:

It was pretty crazy stuff, but definitely very interesting. And so that was when I started, and I became just even more and more interested into FEA. That’s when I decided to launch my blog, because everyone who starts into FEA has to go through this process. So why not tell everyone what I know through my blog to share my experience, teach everyone else. It’s good for everyone, good for me. It’s good for all them. This is really interesting. So, I started to do that to publish videos, to teach people. And afterwards, after MIDAS I went back to China. I worked for some time for EDF, the electricity company in the nuclear field. There, I was doing also some mechanical simulation for nuclear systems. And now, two years ago I went to OnScale where I started to do the as engineering director Asia for OnScale because, like I told you, I speak a lot of Asian languages. So very efficient to find the good people in Asia, to present the softer and to also solve problems in various languages. So yeah, that’s it.

Jousef:

That’s great. That’s great. Going back to FEA, if a newbie in this field watches this video, how would you explain him to him or to her? Why would we need FEA? Why is it necessary?

Cyprien Rusu:

Okay, that’s a very good question. Why do we need FEA? Well you have to consider that as engineer, what is the purpose of an engineer? Engineer basically build things. We are builders, right? We create new things from scratch. We create systems, we create reality. So, you need to have some system in place to help you to do that. Some tools to do this. When you design a system, you design something, especially when it’s a mechanical system, the worry is basically will it work? Will it crash, will it be destroyed under certain circumstances, under certain kinds of loads? And you understand that if you are engineer in a business which has very high stakes, like you can think about nuclear, you can think about aerospace. If you design a plane, you design a nuclear power plant or stuff like that. It cannot fail.

Cyprien Rusu:

You cannot take the risk that something breaks loose and, bolts breaks loose and everything explodes, right? So you have to be sure 100% about your job, and about the accuracy of what you’re doing. Those systems are so big that you cannot say, “Okay, I will build a prototype and I will try to see if it breaks on that.” You cannot build a power plant prototype and hope that, make it explode to see if this will work. So, that’s why in these critical areas where you really have some dangerous systems, that’s where FEA is the most important because this allows you to move to basically make virtual experiments on your computer. Instead of going out in the wild and making some prototype and trying to break it with some machinery, you’re just doing the same stuff but inside your computer. This allows you to take no risks at all, because you’re able to break things and look at how it breaks simply by using your computer.

Jousef:

So what we are basically doing is some kind of simulation, right? We would try to mimic the real world. How do you think that, say if we have a complex loading on our component and we cannot really mimic that or implement that into our FEA software, how do you think, how can someone manage the real world behavior?

Cyprien Rusu:

There’s always a difference between the real world and the model, right? Because we want always to get as close as the real world as possible. But we have to be aware that what we get on the computer is not the real world. That’s a model of the real world. There are assumptions, approximations behind stuff. You have systems, the mechanical system you have, always have some kind of things which are simply not real. Because for a lot of reasons, you cannot model 100% of reality. There are several reasons for that. Some reason is, sometimes it’s just too complex to model reality because reality has so many phenomenons and physics involved. And the second reason is, do you really need to simulate all that? Why would you simulate a freak behavior over an airplane, if what you’re interested in is really the stiffness of the airplane itself?

Cyprien Rusu:

You can simply approximate the air flow by using some loads, so you can say this is an approximation of the reality, but this will always be an approximation. So to answer your question, there is always a way to simulate the loads that approximate the real world, let’s say. Because you know what are the kinds of loads that exist in the world. There’s only a limited choice, the force, the pressure moments and then you have all that depending on time, temperature, and all of that are physics that are modeled by the solvers and different kinds of loads. So of course, you’re not always able to do it within a certain software because maybe this software has some limitations, but that’s another topic, right? It depends on the implementation of the people who have developed the numerical code. If you suppose that you have full access to the software, you’re using something open source for example, and you can develop the numerical methods you need to use and to change the loading. Well, I would say that you can do pretty much whatever you want.

Jousef:

Are we living in a simulation? What do you think?

Cyprien Rusu:

I don’t know.

Jousef:

You don’t know? Okay. So let’s say someone wants to do an FEA analysis, and of course a lot of people trust what they see in the computer, right? They see maybe red numbers, like red legend, maybe it breaks, maybe doesn’t break. How far often of a good engineer do you have to be to really understand what the computer shows you? You also have to put it in your own expertise. Right? Cannot trust the computer itself.

Cyprien Rusu:

Yeah, of course. So how good engineer you have to be to understand, what you see inside the computer. You have to be aware of certain stuff. First, do you mean someone who modeled something himself inside the software, and then look at his own results? Or do you mean someone who looks at a simulation done by some experts who know what he’s doing, and then doesn’t understand the results? What do you mean?

Jousef:

First, if he’s doing it by himself and then looking at the results and then say, “Okay, I did it, so it must be right and I trust the computer.” How do you see that?

Cyprien Rusu:

Okay. That’s a big problem, because I think lot beginners have this mindset that they don’t understand how the software and the algorithm behind it work. So, they tend to think that computer cannot be wrong, or whatever I see on my screen is correct. Of course not. Of course not. What is the software? The software is just a tool which basically show you, if there is a graphical interface, it’s just a way to translate the physics and the algorithms that are calculated behind in a graphical way, so you see what happens. But if you think about the algorithms in themselves, do you think that algorithms are always right? Of course not. There are a lot of assumptions that are involved. Algorithm have to converse towards a solution, and you have to use the right algorithms as well.

Cyprien Rusu:

If your software doesn’t implement the right algorithms, and if it doesn’t do things in the right way behind the screen, software can be wrong. So, it totally depends on the software. But I’m not saying, most of the time the software is not the problem. Most of the time, the user is the problem.

Jousef:

Yeah, definitely.

Cyprien Rusu:

I’m just saying that the software might be wrong as well, but most of the time the main problem comes from the user, and it comes basically from the fact that people want to do something very quickly, without having to think too much about what they input into the tool. But really what is important in FEA is the input you give. If the input is wrong, if the material properties you’re using are not correct, of course you get something which is not correct at the output.

Cyprien Rusu:

There’s a principle for that called the garbage in, garbage out. Beginners tend to ignore this fact and they’re just like, “Okay, I’m following a tutorial, something they tell me to do like this.” But the tutorial is just one example of what you can be doing, but everything depends on your model, on what you want to simulate, what you want to do, what kind of application you have, what physics is involved, what kinds of assumptions you’re doing, the size of your loading, the type of boundary condition you are using, the mesh size. All this stuff is important. So, you obviously have to know in some way, all of this to be able to simulate something correctly. Saying that if you don’t know anything, and you just throw a model into your computer and you look at the results, I would say 90% of time this is wrong.

Cyprien Rusu:

But there is a way to kind of come back to reality and see if this is correct or not, it’s to compare that to an experiment of course. If let’s say you are comparing what you see on the screen with the real experiment, and you are doing a matching of those results, well then you get some way to evaluate and to compare reality with the simulation. And if you get this way to compare, then you have a way to say, “Okay, I’m wrong or I’m not wrong.” And of course, it takes also some knowledge to do experiments the right way, so you need to have that as well. But that’s the way I see beginners who would like to know if their result is wrong or not, could do. Now, what I always tell to my students and people who read my blog is, take the time to understand how this works. Take the time to understand the system.

Cyprien Rusu:

Don’t rush to a solution or just clicking a few buttons. FEA software is an engineering tool. It requires some reflection, some thinking about the physics. It’s not a MS Word processor. It’s not about doing something quickly, and you see your result that you can judge like that so quickly. It requires a lot of experience. So, to answer your first questions, how experienced you should be? Well you should be experienced enough. That’s what I want to say. You should be clear about the engineering method you use and you should be clear about the physics which is involved, and you should know what is stress, what is the displacement? And you should have those basics in order to at least judge, and always keep in mind that you can be wrong. Computer can be wrong as well. Most of the time you are wrong. So try to, let’s suppose that you are 90% wrong all the time, and that if you keep trying and you should keep using the good method, maybe one day you will start to be less wrong until it will start to match real results.

Jousef:

That’s good input, Cyprien. Thanks a lot. There’s this famous 10,000 hour rule, which says once you have reached the 10,000 hours, you’re an expert in this field. Do you believe in that? And do you think it’s applicable for the field of simulation?

Cyprien Rusu:

Yeah, of course. Well, who said that? I forgot the name of the guy who told about this 10,000 hour rule. But I agree with this, and I disagree at the same time. What I want to say is that if you spend 10,000 hours, it’s sure that you will be an expert, but you can be an expert without necessarily spending so much time. It really depends how much you are focused on this, and how much you’re focused on relearning the stuff and trying to understand this, because if you spend 10,000 hours, it really depends on your concentration every day. If you’re just learning 30 minutes, for several years, you will become an expert of course after several years. But if you really do the job to read a lot of books, to ask lot of sample questions to understand what you do, to do a lot of practice, this can go really fast and much faster than you think. I would say it really depends on the people and your background, and what you really want to achieve on that.

Jousef:

I see. So let’s say someone wants to delve into the field of FEA work. What resources would you recommend to him or to her apart from the software? Software doesn’t matter. First, what resources would you recommend to get started or to delve deeper into the field of simulation?

Cyprien Rusu:

Well, to get started, you can start with my blog of course.

Jousef:

Yeah, of course.

Cyprien Rusu:

It depends what you want to learn. Ask the right questions, read a lot. Actually I have one rule to learn something, in my opinion, the best way to learn something is really to find the best book you can find on the topic, and take some time to choose a good book, not the first one you can find in the library or something, but really something which has been recommended by a lot of people. Just take this one book and spend some real time to read it chapter by chapter, do the exercise and go over the stuff. Practice a lot, ask some people, and if you do like that, you will become proficient very, very shortly. And if you have some doubts or anything, you can send me some questions. I have a lot of people asking me this question actually, through the blog, through YouTube. I have a basic free course also on the blog. So, you can really, there’s a lot of ways to learn. It depends on your own motivation.

Jousef:

Very good. Thanks a lot, Cyprien. There’s a lot of abbreviations in the field like CFD, FEA, FEM, CAD, CAE. Can you explain the difference between CAD and CAE? What the difference is?

Cyprien Rusu:

Yeah, of course. That’s maybe something that as a real beginner, you’re wondering, like you say, you have lots of abbreviation, you don’t really know what it means. Well, CAD means computer assisted design and CAE means computer assisted engineering. So, the difference here is really between design and engineering. When you talk about design, it’s more the graphical aspect that enters into play. You’re thinking about basically making the CAD of the model, the graphical model, the geometry. CAD is about designing the geometry of your system in terms of shapes, lines, nodes and all that, and CAE is about applying engineering methods to do some virtual testing on this geometry.

Cyprien Rusu:

So, those are two different aspects in the CAD process, is just about creating a geometry. It’s 100% about the visual aspect of it. Like, how do I make my faces, how do I generate these kind of shapes? CAE is about, okay, now I have this virtual geometry, how do I transform that into a numerical model, and how do I do some virtual testing? How do I apply loads? How do I do some tests of the stiffness of this model, of this trends and how do I out some results that I will need to understand the physical characteristics of this geometry?

Jousef:

What would you say? What are the barriers of FEA? Where’s the limit of FEA?

Cyprien Rusu:

Well when, when I started really using FEA, finite element analysis, I always wanted to think that you can simulate everything. Now in my opinion, I still sometimes think that there’s no real limits to FEA because everything depends on the engineer imagination. If you really need to simulate the system, you can always find a way to do it, to make a model which will be more or less accurate and to understand that. But you always have to think that the limits of the model and the simulation is the physics, right? You cannot simulate something which will be un-physical, and you always have to stay in the bounds of reality and in the laws of physics. Sometimes that’s something that people don’t understand the physics. They want to get out, they want to simulate something.

Cyprien Rusu:

But sometimes it doesn’t even come to mind that this might be un-physical, and that’s the problem, because this is totally 100% virtual. So we can take any model or we can put any kind of load and just look at the results. But in reality, will you have this airplane with this huge load on it? Never. If you stay within the bounds of the reality and the physics you are simulating, I think FEA can give you the right answers. Now, if you really want to dream and to make some science fiction, then better to try some After Effects and to make some cinema movies than use FEA.

Jousef:

Yeah, that’s good. I want to also give you some philosophical questions. What I’d like to ask us, let’s say the phone rings now in your room and you pick it up an 18-year-old Cyprien is on the phone. What would you tell 18 year old Cyprien? Some tips about life, about simulation maybe, what would you tell him?

Cyprien Rusu:

That’s a very good question. Let me one minute to think, because I’ve never thought about that. What I would tell myself, I don’t think I would tell myself anything actually, because I think life is much more interesting if you don’t know what is happening in the future. It’s always some kind of discovery for me, learning new stuff all the time. Going from one thing to another, learning new ways to think, new ways to evolve. I believe that what is important is the process of this learning, and you cannot jump from point a to point B. If someone tells you something 20 years after, “This is critical, important for your life.” Well if this is important for your life, like I don’t know, don’t go in this plane because it will explode like in the movies, then I’d probably tell it to myself of course.

Cyprien Rusu:

But I’m talking more in a realistic way. I’m not dead right now, so obviously I can give some advice to myself. And what I mean is that, what is important is the learning with serendipity. I don’t know if you know what is the meaning of serendipity. It’s the concept that you basically want to learn something, and on the way to learning this thing, you discover three or four new things that you weren’t aware about it before. And you start to go in this direction, and after some time you discovered, “Wow, this thing that I was never even aware about. It’s so great. It’s so interesting, and it can change the world so much I want to learn that.” And then you repeat all of this process for several years, and you start to see that you are evolving towards a certain direction and learning very interesting stuff.

Cyprien Rusu:

So, my only principle is just, if something is not working for you, just ditch it out. Sort it out. Don’t spend too much time doing things that do not work, or do not interest you. Go in the way which has the maximum learning for you. That’s my philosophy, let’s say, because some people ask, “What is the easy way? What is the way to do this kind of stuff easily?” I never asked myself this question. I always prefer the hard way, which is to learn things in a very difficult way, because I believe that this brings you a lot of stuff on the way that you simply cannot foresee these things in the future. And if I was telling me this in the past, I just wouldn’t listen probably to myself in the future. So, it’s useless when someone tells you something. You have to discover it by yourself in order to really take it seriously. You know?

Jousef:

That’s great, yeah.

Cyprien Rusu:

I don’t know if you have this experience, but it’s very… I have a lot of people here. I tell them, “You should absolutely read this book.” And most of the people, like 99% they’re like, “Okay, yeah, I’m sure I have to read it.” And then what happens is, five minutes after they just forget about this. But when someone tells me this, and I trust this guy, what I do is I immediately buy the book and I start to read it. And if this is bullshit, I just drop the book. But if there are interesting things in this book, I just learned from it. So, always try to experience things.

Jousef:

Yeah. Great, great. Cyprien, what is fulfillment for you? What gives you fulfillment? What would you say?

Cyprien Rusu:

Well, I would say learning a lot of complex things, and just enjoying the result. If you learn some new methods, or some new language, or some new things at the beginning it’s hard. But after a few years, you realize that you can do those things so much faster than anyone else. So, it’s just enjoyable to you, to improve your skills and to improve your mind to think faster, and then you will always discover that there are always people who are more intelligent than you, so that’s even better because you can learn from them.

Jousef:

Yeah, you’re completely right. I think if you’re the smartest one in the room, then there’s something wrong. So, I wouldn’t like to be the smartest one in the room. Definitely not. Anything else you would like to let the people know about you as a person, apart from all this simulation stuff? What should people know about you?

Cyprien Rusu:

Well, they should know that I really like to talk to people, and to help people to do things. So really, if you have any questions, you need any help on some things, you’re free to contact me. I cannot guarantee that I will always answer you, because I receive thousands of emails every day. But really, if there is some interesting problem and if I can really help on something, always happy to receive some emails and comments from other engineers.

Jousef:

That’s great. So, we know each other for over seven years now, and it was really a pleasure talking to you. And I will put every link to your blog, of course, which is great, and also your YouTube channel down in description. In case you want to contact Cyprien, I will put just everything down in the description. So, it was great talking to your Cyprien, hope you stay safe and healthy. And I would say, see you soon hopefully.

Cyprien Rusu:

Yeah. Thank you, Jousef.

Jousef:

Bye.

Cyprien Rusu:

And stay safe, as well.

Jousef:

Yeah, thanks.

Cyprien Rusu:

Bye.

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Thanks as always

Cyprien “Engineering Knowledge First” Rusu

PS: I took this image last year before all the current madness… Hang in there and stay safe!