Name: Designing the Perfect Fireman Helmet with SOLIDWORKS & 3DEXPERIENCE Lattice
Uploaded: 2025-06-17T20:31:32.982Z
Duration: 44 min 26 s
Description: Designing the Perfect Fireman Helmet with SOLIDWORKS & 3DEXPERIENCE Lattice

Transcript for "Designing the Perfect Fireman Helmet with SOLIDWORKS & 3DEXPERIENCE Lattice": Hello, everybody. Thanks for coming to our presentation, designing the perfect fireman's helmet with Scanning, three d Printing, and ModSim. Today, we have Matt Schirach, Steven Darcy presenting, and we'll get to some introductions in just a moment. Brief introduction of our topics today. We're gonna start with, introducing the presenters, then we'll discuss three d scanning and reverse engineering, and then how to get that three d scan into CAD, for alignment and, purposes of reverse engineering. Then we'll talk about creating a lattice. Then we'll run a simulation, validate some results, do an optimization on those simulation outputs, and discuss three d printing. So let's begin with the introduction. Thanks, Matt. Hi, guys. I'm Steve Darcy out of Austin, Texas. Got my mechanical engineering degree at UALR. I'm an elite applications engineer, an expert in three d design. I like anything robotics, automation, technology. I'm a two times marathon finisher for Austin marathon, and I like any kind of computer software, three d printing, or pretty much anything nerdy. Alright. Back to you, Matt. My name is Matt Sherak. I am a senior simulation product specialist here at GoEngineer. I work out of the Denver, Colorado office. And as such, I like to do all the typical Colorado things, hiking, biking, spending lots of time up in the mountains. And I've been making a killing on chicken eggs, with my backyard chickens. Also, I have been doing simulation all day every day for the better part of ten years. Some might call me an expert, but I am constantly learning new things and discovering new things about simulation. So I'm really excited to be here and be presenting this topic for you all. So let's discuss the inspiration for this presentation. Despite popular belief, working at a reseller can be dangerous. Lots of shenanigans happens around here. So in between shenanigans, I happen to be perusing YouTube one day, and I found the video, that you can see in the bottom right hand corner. You can view the video yourself with the QR code there. But they discussed the mass customization as possible using three d scanning, three d printing, for, like, the helmet industry. So, you know, certain professional sports leagues and things like that, they already use this similar kind of workflow. And I thought, well, here at GoEngineer, we have everything we need to do this exact thing. So we decided we were gonna make a fireman's helmet because that was easy for us to get our hands on and do a quick three d scan of. So how do we go about doing this workflow? We're gonna need a a sort of a bill of materials of a little bit of hardware and a little bit of software. Software. So in this demonstration, we're gonna on the software side, we're gonna be discussing mostly the three d experience suite of tools, including CATIA for computer aided design, reverse engineering. But we'll also discuss the three d experience add ons that allow you to do, collaboration, file management, the lattice design obviously, and then simulation as well. So everything on the software side, we should be able to accomplish all on one platform, which is amazing. In terms of hardware, we have some three d scanning solutions from Artec and Creaform, that we have access to and then we have a full suite of three d printing solutions, from Stratasys that we'll be using in this presentation as well. So that's enough of an introduction. Let's begin talking about three d scanning. And I'll hand it over to Steven Darcey. Alright. Thanks, Matt. So first off with three d scanning, first thing we did is went down to our Austin fire department and grabbed one of the guys' helmets, took it completely apart, put a whole bunch of little dots on it. And then after we got the dots on it, then we were ready to scan. Andy is our local scanner guy. So you just scan that dude up. And you see while he's painting it, adding it to a mesh on the computer. Pretty cool. Alright. And then once he did one side, we had to flip the thing over and do the inside. And then once we got that done, then we pulled it into some VX software, and we're able to export it as surfaces. And with the three d scanning done, we're on to reverse engineering. Okay. One thing that I found that was quite useful was bringing the step into CATIA. So the surface model is in CATIA. And then I'm initially just gonna create an access system, which is kinda like my zero zero zero for x, y, and z. And then under tools, it'll go to the measure inertia of the part, and I can pick on that surface, which gives me kind of the zero of just the surfaces out there, and it orients it correctly too. So then all I have to do is move it from the inertia of the scan to zero zero zero. And then you can see if I just rotate this guy around, we look at, like, the top view, front view. You can see it looks really nice and straight. And so now that we have it all nice and straight, we can just export it out and bring it as a step file. And then with that step file, we'll bring it into SolidWorks. Alright. So we go into SolidWorks. We're gonna open up that centered step file. So we'll just open that guy up. It does have a lot of surfaces to it, so I sped this guy up considerably so you guys don't get too bored. And then once it comes in, comes in all nice. It is a step file. It's linked to the original, so I'm just gonna break that link. There we go. I'm not worried about it updating or anything like that. We have a little extra surface. I'm just gonna delete that guy out of the way. And then now we want to go in and start creating a parametric file, And we'll save that as the fireman's helmet. Alright. Then we're just gonna create a spline halfway through the part, and I'm gonna try and line that up on the virtual sharp of that surface. And then I'm just gonna do a three d sketch on a surface and just make a spline. We do have to create some constraints. I wanna make sure that it's tangent on the front and the back end of that spline. And then once it's on there, then you may have to kinda drag this thing around or add some some constraints and dimensions to tightly fit that, you know, as close to the surface as you can. Then once I have that, now I need to do the bottom part. I'm gonna do this very similar to it. I'm also gonna draw a line down here, that I'm gonna use that one later for a plane. And then same thing, three d sketch on surface, and then we'll add some constraints on it, some lines out the side. Make sure those are tangent, and then drag those to where I'm I'm fitting to that surface. Alright. So I have my top and the bottom. Next, I need some guides through the center of this. So the the top and bottom are kinda my u direction. These are gonna be my v direction. And so once I have that spline and this is just a two point spline. I'm just gonna drag the handles and get that as close as I can. So then we're gonna sketch on this plane through the center of it. And this one, I'm gonna make sure that I use some constraints to make sure those are pierced through those guide curves, and then we'll drag that in. This one's not going quite the way I wanted, so I may have to and this happens occasion where you go back to the original, you drag that around, and then that's gonna update the pierce on the secondary sketch. And since now it's tight, that looks pretty good. And we'll finish it out on our third sketch and make sure that that looks good, contours well. And then we're just gonna do a boundary surface, We're gonna go through the v direction, and then the pink is the u direction. We'll add some constraints, make sure it's normal to the profile. And then there's our first surface. And if we turn on our initial surfaces, then you could see we've got a pretty good, correlation between the two. Alright. With that done, we're gonna sketch back on the front side plane. I'm gonna start working on the Mohawk area. And, again, just just a two d spline on a plane. And then we're just gonna extrude that back in space. I know I'm gonna need a couple more guides, so I'm gonna add two more in there. We'll create some planes on that. And then we'll just do a three point spline, and we'll make sure that we're doing pierce through the edge of the surface and tangent to the surfaces, try and guide them, make sure that they're pretty close to to that end surface. Alright. Once they're on there, we'll turn off the original surface, and we'll just do a loft. So surface loft using the surfaces as guides. And then the last thing is to put two filled surfaces, and then that's starting to look pretty good. We'll just knit it together, and we're done with that section. Next, we're gonna do kind of the brim area. So I'm gonna create a sketch on the top view and just kinda get close to that. And, again, we're just gonna do a surface extrude, and then I'm a do a side view of that, get that one kinda close. We've got couple different spline points in there, and then we'll extrude that out too. So I have two intersecting surfaces. So now I have a three d spline where the intersection occurs, and then I just need some cross sections. This time, instead of using a spline, I'm gonna use an arc and a line command. And then I'm gonna draw a bunch of straight lines, put a bunch of planes through those lines, and same thing. I'm gonna draw a bunch of lines with arcs. And that way, you can kinda control and make sure that the the flare out is kind of conical as it sweeps around there. And then once you get them all pretty close, then we can turn off the main surface. We'll just use those profiles for the loft. And then we have the guide curve of the three d sketch and the surface. And we'll say okay. And that looks pretty good. And so the next part of this, gonna use the part reviewer, and we're just gonna take the features down one at a time. So we do some surface sweeps. We do some revolves. We do some fillets to make it look cool. We'll knit it all together, then we'll thicken it. So now we have a solid part. We'll do some surface cuts. We need to add a little, surface brim on the end of it. And then to add some drafts, some more surface cuts. And then kinda once we're done with the outside of this thing, we gotta do a little bit of work on the inside. So let's rotate that around. Let's go back and put the fillets back on there real quick, and that looks better. Then on the inside, we need something to hold our strap on there. So we'll just sweep that out. We'll combine it, add some fillets, and that's looking pretty good. Last thing you do is just mirror the thing, and we've got a fully parametric fireman's helmet. So that finishes out the reverse engineering. Now let's take a look at the alignment of the scan and the CAD. So in order to make the cushion, we're gonna need the helmet and the head. So let's get to it. We have our models in SOLIDWORKS, but we need to get them on the cloud. And something we can do on the cloud is to make a bookmark. It's kinda like a folder on the cloud. So I'm gonna call this one three d x world twenty twenty five, and it's just a depository for us to put stuff. So then I'm gonna launch design with SolidWorks. So that's gonna launch SolidWorks, but also have me logged in as my current user. So we have an IGES file called Matt is a NERB. This is his head model, an exact duplicate of his head. So we're gonna go ahead and break the link of the IGES file. And then when we go to save it, you'll notice that it's automatically giving me a part number for the file name. Alright. So then let's go ahead and open up the fireman's helmet, and that is our fully parametric SolidWorks part. And we're just gonna dump these into an assembly. So we'll just insert the fireman's helmet, then we'll insert Matt as a NURBS head. It's looking good. I'll rotate it around just a little bit just to orient it, and then we'll just start to assemble it. So we use the same moment of inertia for the planes. So as long as we line them up, then they should be somewhat symmetric. Here we're just gonna do a little parallel, and then we'll do a quick section view. And then we can just drag this into position and just kinda center it as best we can between the front and the back. And because the helmet is parametric, we could make it larger if we wanted to now. So that's looking pretty good. We'll double check it with a little quick section, and we'll save this out. You'll notice that we also have automatic file names. And before we save them up to the cloud, we're gonna go into the dialogue box, and we're gonna go ahead and select the proper bookmark. So go ahead and browse for it since it's new, and there it is, 3XWorld2025. So I'll apply to all. So all those files, if I go look in that bookmark, we'll be able to see them. So now we have the assembly, the fireman's helmet, and Matt Sherak's head up on the cloud. Now we need to make the cushion. So let's take the assembly. We're just gonna do a save as, and we're gonna save this as a part file. So then we'll just open up that part file. So now I have a part with two solids in it. So the first thing I need to do is go ahead and create a block that is the size of the largest amount that I can print on my three d printer. So So in this case, it's nine and a half by four inches. So I'm gonna go and just drag this around just to kinda get it close to where I'm getting the most amount out of Matt Sherak's head and the fireman's helmet. So drag that into position. And, of course, I could fully constrain it if I need to, but that's close enough. And since this is a three d cushion, we just need to extrude that up midplane. And whatever the extents of our printer is, which is seven and a quarter, I also wanna make sure that when I extrude, I am not merging the result. So when I'm left, I have three solids. Then all I'm left with is to do a combine. I'm just gonna subtract one solid out of the other. So now I've got Matt's Sherak removed. Now I just need to remove the inside surfaces of the helmet. So let's go ahead and just do an offset surface of zero, which is gonna do a copy surface, and I'll just select those inside surfaces. That looks good. We'll go ahead and turn on the cushion, and we're just gonna do a cut with surface. So now I have the exact duplicate of the top of the fireman's helmet and the bottom of Matt's Sherak. And with that, we'll go ahead and select the right bookmark and save it up to the cloud. So now that we're on the cloud, we can put look in the bookmark, and we could see we've got four solvers files. We've got our assembly with the two parts, and then we have our cushion. And we can add descriptions and and other attributes to help aid in searches. And with that, we're ready to create our lattice. Initially, we created a lattice, and we just brought it into the software. And we clicked a few buttons, and this is what we got. Real simple, easy to create. It's real choppy around the outside and the inside of the surface. And we went ahead and three d printed one, and when we put it on our Sherak, it really hurt. So we decided to make it a little bit cooler. We decided to use an inside and outside surface. That way, it would grab to the fireman's helmet really well and also perfectly fit your head. So in order to do this type of a lattice, we had to create a partition solid to tell the software where to actually lattice the part. So let's get right to it. Lattice Designer is a native app that runs inside of the three d experience platform. And since they're SolidWorks files, I'm initially gonna start out native apps with assembly modeling. So we'll go ahead and launch native apps. I'm gonna go ahead and just start with a physical product, which is an assembly. And then with that assembly, I'm just gonna drag and drop the SOLIDWORKS file in there. Now the SOLIDWORKS file is read only, so the only thing I can really do is drop it into assembly. I can't make any changes or updates to that file. So in order to do the lattice, I'm gonna go ahead and insert a three d shape into the product. And once we have that, now I can edit the three d shape. So I double click on that. And now we can actually copy the solid from the SolidWorks file and paste it into the three d shape. So I'm just gonna do it as a result. So that looks good. And then I'm gonna change this to the part body, which is kinda like the main solid, and I'll just delete out that extra solid there. Alright. With that done, we can actually turn off the SolidWorks file, And now we have a three d shape that has that solid body. So initially start with part design. I wanna select some edges to create some fillets, so that way I have a tangent face all the way around the outside. Just gonna make it easier for selecting. Then I'm gonna go into generative shape design and go ahead and start offsetting some faces. So I'm gonna offset this face pretty much one millimeter, point o three nine inches, and we'll go and offset the outside face as well. And we're offsetting them to where I'm creating a solid inside this area. K? Then I'm gonna offset a plane. I want that plane just a little bit above just to make sure that the partition solid is inside of the main solid. Alright. And once I have those, I'm gonna go and extend the outside edges of those surfaces just a bit, and we'll go and extrapolate or extend that other one as well. Then I'm gonna go ahead and split those with that plane. So I kind of extended them up to the plane. I wanna make sure that even though they extend, they cut off flat against that plane. So we're gonna do the same thing on the inside one. That looks good. And then I'm gonna create two boundaries, one on the outside and one on the inside. And then with these boundaries, boundary three and four, I can do a fill. So the outside fill is gonna be that boundary three. The inner boundary is gonna be four. It's just gonna make a solid flat face there. So with all of these, I can join them together. That creates my inner boundary, and I have to do a closed surface for the lattice to use as a volume. So just keep in mind that the darker is the volume surface. So next, we're gonna go in. We'll just add some properties. I'll just call this guy the lattice volume, and we'll go ahead and add a title. Call it Matt's cushion for the lattice, and we'll save that up to the cloud just to be safe. Then we'll go ahead and hide the volume. We'll go ahead and turn on our original solid, and then I want to create some little air holes. It was a little bit warm when we first put this on, so I wanted to put some air gaps in here. So I'm just gonna go ahead and offset this surface, then go into, part design. And once I'm in part design, I'm gonna offset a plane. Just put this way up on top of the part. Eight inches looks good. We'll just simply do a two d sketch on this plane. We'll just draw a circle out of here and add some dimensions. And once I get the dimensions on here, we're just gonna do an extrude cut or cutie, we call it a pocket. And I'm gonna say up to surface, and I'm gonna select on that offset surface. So you can see it's going down into the part. I also went down a little bit further than that partition surface. And then we'll just do a circular pattern, put five of them out here. That looks pretty good. Make sure you check the box for keep specification, so offsets to the surface. And then we'll put some fillets on there to make it look cool. That looks pretty awesome. Alright. We're almost there. Now we can switch back over to lattice design. And in lattice design, I'm gonna go ahead and turn on my lattice volume there, and we're gonna do a partition. So you can kinda see the dark gray area is the part that's actually gonna get the lattice, which is gonna leave a little thin film on the inside and the outside except for where the boundary holes are. Also, when you're doing the partition, make sure you turn off your join. For some reason, it won't let you select that with the join in the closed surface on. So now that my partition is created, we'll go ahead and turn off our lattice volume, and then we'll go right into the lattice design assistant. Now this is a simple little five step method. We'll just hit create. We'll tell it the solid that we want to do the lattice on, which is the surf cut, and then the volumes. There's actually three volumes with the partition. We're gonna do the middle one. You can see we got the inside and the outside. Then we can select our lattice design. So we have different ways to conform the lattice. In this case, we're using rectangular. We have TPMS, which is pretty much surface lattices. You And so we have a wide variety of surface lattices. Then we can also do different types of bars, crowns, cubes, diamonds. We're gonna do diamonds. Matt's gonna tell us a little bit why a little bit later, and we'll just set the size of it, and we'll take a look at the preview. We'll take rotate that around a little bit, and we can kinda see that that looks pretty good. Size and the radius are very important here. Now when we start to do optimizing, these will be the parameters we can control. Alright. Then we can do concept information, which is gonna tell you the volume and the percent fill. And then the last step is the design detail. So we'll click on that. We have a decimation sag, and we'll hit okay. Now this did take about seven minutes to complete, so I sped this up so you guys don't get too bored. And once it's done, we can close out of the assistant, and we can rotate around, take a look at what our lattice looks like. We have to do some gratuitous panning and zooming just because that's cool, and then we just need to save that out. And just because we saved it doesn't mean it's in our bookmark, so we'll just drag and drop that into our bookmark. So you notice we've got our SOLIDWORKS files, and then now we have our CATIA Lattice file. Now that's saved, we can export it if we want to just to do a prototype, and we'll save this guy out as a STL. And with that, we're done with the lattice, and we'll hand it over to Matt. Thanks a lot for that, Darcey. I get the feeling that you did most of the hard work on this. The simulation part, as we'll see here in a minute, is actually really simple. So let's dive into it. The three steps to creating a simulation using the three d experience suite of tools are first, you generate a finite element model. So this is taking your CAD geometry, discretizing it with mesh elements, and then assigning materials and connections, that type of thing. From there, you define the physics that happened to the model or the scenario as it's called in the three d experience tools. And then after that, you run it and you get results. So we'll start from the beginning and kinda work our way through this process. So to create a finite element model of our structure, we first need a CAD model. So this is the the helmet, and you can see that I've also put a impactor on the top side of it, then that's what we're gonna be dropping onto the top of this helmet for our validation case. Alright. So everything looks great here. We'll go ahead and begin the structural model creation app. This is where we create meshes and assign material properties, that type of thing. So once we're in the structural model creation app, we'll go to the mesh tab here. And I'm gonna begin, taking this beautiful helmet that Darcey reverse engineered, and I really only care about the outside surfaces. So sorry, Darcey, but for simulation purposes, we don't need all of this. So I'm gonna use a tangency selection here to just grab those outer surfaces of the helmet for our mesh. This is going to be what's called a shell mesh or a two d mesh for that outer surface of the helmet. And then once it's complete, it'll look like this. So you could see nice quad elements on there. From here, I'll be creating meshes on the other components. So this is a three d tetrahedral mesh on the impactor, the steel ball. We'll also do a three d tetrahedral mesh on the representation of my head. It's always strange seeing your head on a screen. And then from here, we're gonna hide the helmet so we that we can get more easily to the inside of things. And we're gonna be doing a special mesh on the cushion, the lattice cushion. So to do that, the secret sauce here is to go to the setup tab and choose the lattice finite element model. So this lattice finite element model allows us to take all the hard work Darcey did setting up that lattice, complete with the definition of the beam radius and the beam length and I can transfer it into a combination of beam elements and solid complementary volumes meshed with tetrahedron elements. And I can enter the appropriate element sizes in this box you can see on your screen. Alright. So now if I turn the meshes back on, I'll have to hide the solid shapes so you can see those beam elements. On the inside, you can see that there's a bunch of beam elements and some, one element thick skins for the solid tetrahedral volumes. So for the FEA nerds among you, like myself, there's a lot going on here. And that was just a couple clicks. So let's dive in deeper and show what that really means because this is sort of the crux of our presentation here. So here's just the the volume of the the lattice itself and if I highlight them you can see that yes we have the beam elements and the complementary volumes tetrahedrons and we can plot the beam elements in three d so you can see their virtualized thickness. Again, this is all pulled from the definition of the lattice design that Darcey had done. It also ties together each of these beam elements to each other and to the complementary volume skins on either side of this cushion as well. So the reason this is such a big deal is if you were to try to take this lattice geometry and make each of those segments of lattice its own beam element and then try to tie that to other beam elements and also go in and tie each of those that happens to be touching the outer skin to the skin. That'd be a very manual and labor intensive process and it would probably take hours and hours and hours to go through that and you would still probably miss a couple of those tie connections. The fact that the three d experience platform does it all automatically for you and so seamlessly is really, super powerful. So I wanted to make sure that we highlighted that for you. So from here, we'll add our material conditions in. The nice thing about working with Stratasys three d printers is they publish all of their material data for their printers. So you can see that I have taken the the material properties. This is for the Neo material, one of our SLA materials, that we have here in the Denver office. And I've created a simple linear elastic, and elasto plastic model for this in our three d experience material data card. So to assign it, it's pretty simple. We just have to grab the individual components and we can sort of drag and drop these materials on to their individual components. So here I've got a rubber that we're putting on to the beams and solid sections of the cushion, and then we'll just use these rigidized materials for the head and the helmet. And then this the impactor will be made out of steel. And then the helmet itself will be made out of that neo material. You could see it's automatically filling in the grayed out box there. We have to enter a thickness for the the helmet, which is three millimeters. And we can control our offsets of those shell elements to make sure that we don't have any strange initial over closures or interferences. Okay. So this is just a review of the different materials involved. You can see on the right hand side is a legend. So I did the the rigidized neo torus material for the head and the helmet. I've got rubber for the cushion and then the impactor on the top is stainless steel three zero four. Alright, so that's finite element creation. It's really simple. The the big takeaway from this is the ability to use that lattice generation that was from the CATIA lattice generator app and use that to generate a mesh of that lattice in three d experience simulation. So it's really a neat functionality there. So next is going to be scenario creation. Scenario creation is probably the easier part for an analysis like this because we're just dropping a steel ball onto a helmet. So we're going to launch the mechanical scenario creation app and this is where we define our physics. For this type of analysis, we'll be doing an explicit dynamic study because it's an impact so it's a high energy sort of fast duration event most suited for the explicit solver. So under procedures, you could see the explicit dynamic step here that enables that type of solver scheme. Alright. So we enter the total impact time. So we'll do point o five seconds or o o five seconds, excuse me. So this is happening very quickly. And then for initial conditions, our only initial condition is that that steel ball is falling towards our head. Right? So I'm gonna grab the debris, finite element representation of that ball and then enter a specific velocity that it's coming down at. So we'll take off the minus sign there so the arrow goes in the correct direction. Alright. So far so good. Pretty simple. Alright. The next step is to define how all of these parts interact with each other. So the general contact algorithm is excellent. This is all based on the abacus solver. It is the abacus solver under the hood. And general contact with two clicks allows you to have sliding contact between all components in your model, all at once. So no face pair clicking, nothing like that. The rest of the setup is very simple. We're going to clamp or fix what is my head in space or my my strange oblong skull in space, for something for the to resist the impact. Right? And then all that we have to do now is simulate this. One of the benefits of the three d experience simulation tools is we can run locally or on the cloud. And on the cloud, we can run with up to 192 cores, CPU cores of cloud compute. That's really overkill for an analysis like this. Just wanted to highlight that for you folks who might be doing very large simulation studies. So I wanted to quickly highlight general contact before we move on. So the general contact algorithm is a modern contact algorithm that I like to say just works. I've used a number of other simulation tools in the past and generally the the way that you assign sliding contact between geometries and FEA is on the left bottom part of my screen where you're saying this component interacts with this component or this pairs of faces on this component interacts with these pairs of faces on this component. And it's very time consuming and, it's sometimes it doesn't even really work right. I like to say the general contact algorithm just works. All of these models that you can see animating on my screen were analyzed with just general contact assigned to it. So it's very robust, it works very well and it's super easy to set up. So one of my favorite features about the Abaqus solver is general contact. Okay. So we created a cool finite element model that was super easy. Scenario creation was also very simple we're just dropping a steel ball on the helmet. And then finally let's look at some results. So on the right hand side of my screen you can see that I'm clicking through individual time steps to figure out at what explicit point in time my contact is beginning to develop here. So this is a displacement plot. So I'm looking for the top of the helmet to begin displacing. Once I know where we're at we can go to a von Mises stress plot and this is going to allow me to animate this plot to really see how the elastic wave propagates this helmet during the impact. Remember, this whole analysis is only taking place for the duration of zero point zero five seconds. So very fast duration. So this is super super slow mo. Right? We can do a section view here so that we can see how the elastic wave propagates through that inner lattice. So as the ball comes down, you can see that the helmet has a lot of stress waves propagating through it but also that internal lattice beam structure rendered in three d for us is sort of bouncing around and is dissipating energy as the animation goes through. I think this next slide does a better job of showing this animation. So we'll go ahead and show that for you. This is a little bit more sped up, but the ball hits and you can see the Von Mises stress, the, stress wave propagating through the helmet. The ball slowly rebounds and even after the ball is no longer in contact you can see those vibrations going through the material. I did another animation of this where I turned off the visibility of the skins. So this is just a very simplified animation of the drop onto the helmet, with nothing really rendered in three d. It's all kind of rendered as as wireframes, if you will. And you can really see how everything's bouncing around much better with this more simplified animation. We can swap to a displacement plot. The colors will look a little more interesting with this plot. So you can see the helmet does kind of squish down and then this lattice structure is absorbing all of that energy and you can really see how much it's bouncing around. So really cool stuff. At the end of the day though, we need hard data out of this. So I wanna know how much reaction force, my head experiences due to this impact. So I'm gonna be doing a reaction force plot, to measure the amount of newtons that are gonna be absorbed by my skull. So it's a little bit shy of 10,000 newtons. So you can see it's 9,950 Newtons. 10,000 Newtons sounds like a lot but if you actually do the hand math without any energy loss to structure deformation or anything like that, the expected impact force, as you can see on my screen here, is 31,000 Newtons. So we already have a 66, you know, about a two thirds reduction in the amount of impact force experienced by my head with the base geometry. So we did finite element creation. We did scenario creation. We looked at some results. So we've done simulation on a lattice structure and we've simulated a lattice. But is it the best lattice? So that's where optimization is gonna come in here. So when we're going to do a parametric design optimization we need to define what our outputs are and what our inputs are. In this case for our outputs we want to maximize safety by minimizing the amount of force on the wearer. So that's the reaction force variable we were looking at earlier. We want to make sure that number is as low as possible. That's our ultimate goal. We also want to minimize the mass of the helmet so that the helmet is still comfortable. So nobody wants a 50 pound or a 100 pound helmet even if it's highly effective because it's not going to be comfortable to wear. So we want to make sure we minimize the mass of the helmet. In terms of the inputs or the design variables we can use those same two variables that Darcey used earlier in CATIA to define the lattice. That's the radius of each of those lattice beams and the length of those beams. So let's take a look at how we can set up this parametric design study. Alright. So we'll search for the parametric design study app and go ahead and launch that, and then it's gonna greet us with an assistant panel that guides us through the setup of this study. So we're gonna click the feature to launch a design improvement study and we can base this on any number of different inputs that are already open in our current session. Next, we'll define our design space. These are our input variables. So we're gonna again use those same two CATIA parameters that Darcey defined earlier. So we'll go into the three d shape for the cushion itself and you can see those parameters listed in the window here. So we can select beam radius and cell length from the list. Click Okay. We could choose maxima and minima for each of these and step size if we so choose. I want a good idea of the design space so I'm gonna leave these values of their default. Next we'll choose our response variables and this is what we're looking to get out of the simulation. Again, safety first. So I'm gonna choose reaction force which is that variable we were looking at earlier, to minimize the amount of force that my head experience is doing to an impact. So we'll choose for objective here to minimize this force. So as it goes through parametric runs, it's gonna choose the one with the least amount of force here. Alright. Next step is to minimize the mass as well. So we'll go ahead and select mass out of the next variables list and also choose minimize for the objective on that one. Click okay. Now our simulation is ready to run. So if we click simulate, we can run 20 design points simultaneously if we want to, each of them with up to eight cores. We could run up to all 20 at once. That's probably overkill. This analysis isn't that complex in terms of computation, but we can if we have the resources available to do that. We'll launch up to four simultaneous and click okay. And once our simulation is completed, our results will look like this. I can peruse each design point individually. You could see me clicking through them. I get the appropriate response variables and the design variables for each of the design points and I can plot these points against each other. So what I'm looking for here is any correlation maybe between, like, the beam radius and the mass of the structure or, you know, between any of our inputs or outputs that I deem necessary. In this case, there's not great correlation. There's always that kind of one outlier there, but we can look for these trends in our data that might not be super obvious. So it gives us best, and we can review the best output here. Or if I wanted to compare everything side by side, I can do this neat lasso selection and grab all my desired design points and put them in this nice table view side by side right next to one another. So it shows each of the designs whether they're feasible, whether they're infeasible, and which one's the best. So in this case, it looks like our optimal output is a point four millimeter beam radius and a nine millimeter beam length. So that's it. We've now made the perfect lattice structure for this fireman's helmet. The next step is to three d print all of the parts for this. So we'll talk about that next. We use two different printing technologies for the fireman's helmet and the lattice structure. We used SLA and DLP. Both of them are liquid resin based printing technologies and they kind of work in reverse of each other. So with SLA technology, you have a build platform that's partially submerged in a vat of the liquid resin and then you have a single laser that goes through and it draws each individual layer of the print itself. So it'll draw a layer, the build platform will go down a little bit, it'll draw the next layer, so on and so forth until the build is complete. DLP works very similarly but in reverse. With this technology you push the build platform down to the bottom of the liquid resin vat. At the bottom of that liquid resin vat it's actually clear. So then from the bottom, we project the entire layer for that print for that layer of the print all at the same time. So instead of one laser drawing the layer, we project the entire print layer all at once. We used each of these for different components of the build and we'll talk about that a little more here in just a second. So for the helmet itself and for our first runs at the cushion, you can see that this is the SLA machine. On the left hand side is the actual speed at which this prints. I didn't speed up that video at all this is taken from my cell phone as these were printing. You can see how fast even though it's one laser it really moves over this material very quickly. Once the parts have completed they're gonna come out of the vat of liquid resin and you can see that in the middle picture here. And they still have a small coat of the resin on them because they're emerging from a vat of liquid. So you'll have to remove the parts from the build tray and then remove the support material that's underneath them. So you can see that support material here. This is kind of like a a lattice like support, if you will, that's underneath the actual helmets themselves. It's very easy to break away. It's very lightly connected to these parts. So you remove the parts from the tray. You remove the support from the parts. You give it a a little bath of isopropyl alcohol to get off the excess resin, and then from there you put it in a UV cure oven to give the the structure a final cure to make sure that it's full strength. We used this technology for the helmets because the helmets are a little too big to fit on our DLP printer that we have available. So for DLP we use the Stratasys Origin One machine that we have here in Denver and you can see in the middle picture there that's the print partially completed. So it's it goes down, it cures a layer, comes up and then goes back down, cures another layer, so on and so forth until you end up with the completed part that you see on the right hand side. You could see there's a little waterfall of resin draining out of that lattice structure. This is useful for this machine because this machine is very versatile in the number of materials it can print and how quick it is to change out these materials. So we use this machine itself because it can print like a rubberized polymer, which is really great for the lattice structure. We learned a lot of lessons when we were going through design iterations of building this fireman's helmet. You should really take into account the printing technologies that you have available when you're approaching any project like this. Design for additive manufacturing, everybody's heard this term, but there is a lot that goes into it. So in our first sort of build attempts, as you can see on the left hand side here, we had the lattice kind of going horizontal sort of like from the left hand side to the right hand side of my head and from the front to the back. And this is fine for the lattice generation and the simulation, but each one of those tiny little lattice beams would need support material in order to actually be printable because they have a large cantilever. So on the right hand side you can see that originally we had this sort of cubic representation that was perpendicular to the print direction which is not actually really feasible because all of those individual lattice beams would need support. So instead we oriented our lattice so that it's kind of standing on one of the vertices of the, of the actual cube that is our lattice. And this is useful because we can print with up to 45 degrees self supporting angles, very easily with this machine. So that means there was no support material to remove from the finalized product. With that, we're through with our content for today. So I just wanted to be the first to say thank you so much for attending our webinar today. This and a bunch of other great content are on our YouTube channel and it's posted all the time on our social media. So please, if you enjoyed this, go and check out some of our other videos. Feel free to reach out to Steven Darcey and myself with any questions, comments, concerns, and we hope to see you in the next