Generative design is very hot these days, but it doesn't help that there are two definitions of it. One generates dozens or hundreds of design variations and candidates, usually in the field of architecture; the other optimizes a single part by repeatedly analyzing it and converging to one optimal solution, usually for mechanical designs. See figure 1.
Figure 1: Parts (shown shaded) and their generative optimizations by ParaMaters (images sourced from ParaMaters)
Well, not so much change as the focus is becoming more in focus. Initially, the impetus for the software was to minimize the weights of parts: the software removes all material unnecessary for stiffness . Then more functions were added, like FEA [finite element analysis], constraints (for locating fasteners), bounding boxes (to restrain the size), and lattices (for semi-hollow interiors). Earlier last year, direct output to 3D printing was added.
Just as I was writing this, Siemens PLM Software announced their plan to eventually extend generative design from single parts to entire sub-systems of electro-mechanical assemblies. And that's really the big idea: software that designs 3D parts, optimized and strengthened, and suitable for 3D printing or machining. We humans just input the parameters, and press Start.
Shortly before Christmas, I spoke with Michael Bogomolny. He is co-founder and chief technical officer of ParaMatters.
ParaMatters CongiCAD
ParaMatters is engineering-oriented, asserting that there is one optimal solution: the lightest possible design that satisfies engineering constraints, like stress, stiffness, deformations, and vibration frequencies. Their software, CogniCAD 2.0, is cloud-based, because it works at very high resolution, dealing typically with up to 10 million elements -- but can reach 60 million. "This is one of our main strengths," said co-founder Michael Bogomolny, "90% of our compute resources are in FEA."
CogniCAD imports STEP files, needing only to retain data like bearing bolt areas, with which the part is later attached to the assembly. The interface has few buttons; you just follow the on-screen menu and go through six steps:
1. Choose the material
2. Select design space; this is the volume inside of which the design must stay
3. Specify areas to be untouched by the optimization process, such as bolt hole faces
4. Apply load cases:
- Static loads forces and moments (available now)
- Vibration analysis (in beta)
- Thermal loads and porous structures (to be added later)
5. Define design goals, such as to minimize the mass so that stresses do not exceed the limits, or else maximize stiffness under material amount constraint
6. Select resolution: 0.5 (low), 2.5 (medium) and 10 million (high) elements, or even higher
The output is a smooth, watertight STL file ready for 3D printing, or you can export the result as a STEP file for import into CAD for editing and documentation. The software runs on Amazon cloud. Payment is through tokens, which are used to pay; higher resolution runs take more tokens, so you would start off with low-resolution runs.
Dr. Bogomolny says, "Our innovation is to design for deformation, stress, stiffness and frequency constraints, with the objective of minimizing mass. Generated designs are ready for manufacturing without any manual smoothing or geometry remodeling, and are output in STL or STEP format. Designs have a very accurate feature-size control, which is crucial for manufacturing.”
Typical design exploration in low resolution takes from 20-40 minutes, while lightweighted design under stress constraints can take from 50 minutes up to few hours. He shows me the trailing arm for a car that his software made 47% lighter.
"Don't just replace a part here or there; redo the entire automobile frame holistically," he says. "Frames of cars could see a 25% weight reduction, but even 10% would be significant-- excellent for electric cars and drones." These parts can only be manufactured with 3D printing, and so this will give a boost to 3D printing.
"Our designs are material agnostic, whether plastic or metal," he says. CogniCAD also works with multi-material designs, and specifies which material goes in which areas of the part. Some need to be stiffer, while other areas need to be more flexible. For instance, put titanium where stresses are high, aluminum where they are lower. Being a single part, less assembly is needed on the manufacturing line.
Today's 3D printers, however, need to be given two STL files, one for each material, although a company in Canada has an add-on that feeds two materials on demand.
The Lattice Controversy
Some other products have sophisticated lattice design systems that produce beautiful-looking interlocking 3D designs to minimize the amount of material inside of parts -- which is particularly important in optimizing 3D printing.
The problem, he says, is that porous structures need to be aligned in the direction of the principal stress. See figure 2. Normal lattice structures go in all directions. They look nice, but engineering-wise they are a waste of material. The user is expected to pick a lattice shape, perhaps not knowing which one to pick. CogniCAD is able to generate the optimally porous structures.He calls it a meso-structure, because the 'lattice' word is misleading for his product.
Figure 2: Meso-structures (variable lattices) aligned in the direction of stressMeta-Materials
Another technology introduced by ParaMatters is the meta-material compiler. You use it to specify the material and lattice properties to handle shears -- transverse or longitudinal -- and to minimize Poisson's ratio -- the amount a material deforms by expanding sideways when stress is applied from the top and bottom. See figure 3
Figure 3: A negative Poisson's Ratio at work
In the real world of nature, the Poisson ratio cannot be negative: materials cannot contract sideways when stress is applied. But using meta-materials design, they can, because of the holes inside the part that the material can budge into -- even with negative thermal expansion.
Hybrid (convergent) modeling worked on kernels developers isn’t yet mainstream, but is a good idea for designers, whose complex ideas can be introduced with mesh models, and then detailed with CAD.
Dr. Bogomolny foresees a future of fail-safe design through generative-designed parts using meso-structures to create redundant structures locally, so that failures are stopped by secondary load paths.
https://paramatters.com/
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| Here are some of the most recent posts to the WorldCAD Access blog:
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Sean Flaherty left Nemetschek as of January 1. He was the company's chief strategy officer and the former ceo of Vectorworks.
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The Open Design Alliance ups the ante by including rudimentary 3D modeling in its DWG API. Extrude and revolve with 3D solids is now part of the renamed Drawings SDK 2019.2 (formerly Teigha). Other improvements include faster display of RCS point clouds through LODs (levels of detail), DWG incremental save and PDF import optimizations, and multi-theaded loading of DGN (Microstation) files.
The ODA also released BIM SDK 2019.2 for working with Revit-format files. This point release creates basic parametric walls, the first step towards creating all Revit parametric elements with the SDK, which is expected later this year, and an initial implementation of RFA family file import.
https://www.opendesign.com
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So now Autodesk has removed my original order for my purchased license of 3DS Max 2014 (a perpetual license), and also completely removed my AutoCAD 2014 perpetual license from my product lists. Both are now unavailable.
Autodesk, in effect, has stolen my perpetual licenses. Granted both versions were 2014 releases but I've spent a lot of money on plug-ins for 3D Studio Max that no longer work with 2019, 2018, or 2017, which is all they now offer. In total, I've spent around $8,620 just for the big items, not including all of the small Mental Ray items for 3D scenes for 3DS Max.
After Thanksgiving 2018, I loaded a trial version of 3DS MAX 2019 just to see what was new. The result was Autodesk modifying my 2014 version of Max to a subscription and so it will no longer load. Now I'm paying $202 monthly for something I owned. Autodesk no longer cares for the user as they once did.
They kept the price for 3DS Max the same as a core value. It's still one of the most expensive applications for 3D animation on the market following Maya, also by Autodesk, and a few others. Some have reported receiving checks from Autodesk. It's hard to claim without a copy of the original order as they modify all old orders.
The war has begun. I'm looking for a class action lawsuit.
- Troy L Cagle (on WorldCAD Access)
I've been a general contractor and designer for almost 30 years and I am still using Generic Cadd 6.1 nearly daily for residential, light commercial, and custom landscape designs. The box set of books and 3.5 inch floppies are still on my shelf, and my original computer and printer are still cranking out designs just fine.
I recently resurrected an old Toshiba running Windows XP and loaded Generic Cadd 6.1 for when I travel, since I'm semi-retired. The program runs just fine. PROBLEM: I can't make the darn thing print to the HP 3050 I have available. I found and downloaded DosPrint 1.1 hoping that would translate the files to the printer, but still get error messages. Any Ideas?
- Ken Proctor
Re: Readers Respond to Will Computers Revolt?
"This means that the AI code for Go cannot teach itself beyond Go by playing something else, like checkers or chess, or going on to diagnose cancer." That statement might be out of date. DeepMind's AlphaZero (the next iterations of AlphaGo) is now claimed to be a self taught master at go, chess and shogi (Japanese chess). So in principle at least, one step at a time, we are approaching general artificial intelligence.
- Duncan Lithgow
The editor replies: I think the question might be, Do we want to have an AI we cannot control?
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I always try to read your newsletters, thanks! I’ve also been enjoying Stephen Hawking’s The Grand Design. The discussions below made me remember Isaac Asimov’s favourite short story, and one of mine: The Last Question.
- Greg Morehouse, ceo
Motovated Design & Analysis, New Zealand
The editor replies: There is a lot of thinking to do about an issue we know little about.
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And here's another thought to throw into the mix: When computers become intelligent enough that they are capable of independent, rational, logical thought, will they logically conclude that they came into being through the actions of an intelligent creator, or will they conclude that they came into existence through random chance? Which conclusion is more logical?
- Bill Fane
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In my opinion, there is no truth in machines nor in their programs; there’s only instructions. If there were truth, it would be like saying there’s truth in a car or fridge or a wrench or a gun. Such propaganda people peddle today in the name of science!
- Chris Cadman
Re: Air Pollution Affecting Hemp Rope
"He replied that modern air pollution was destroying the original rope material." There's a fashionable trend to attribute everything bad to climate change or pollution. But I think that hemp rope has been considered a temporary solution for many thousands of years. From the perspective of the 1700s, it was the worst possible material to make a marine rope out of, except for all of the other materials.
- Jess Davis, president
Davis Precision Design, USA
Re: 1,001 Issues
Congratulations Ralph. Every one has made a positive contribution. I look forward to many more.
- Malcolm Davies, ceo
Techevate, USA
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Congratulations on reaching 1,001 issues. It is quite an accomplishment. I’m sure you’ve outlasted many of the companies and applications that you’ve reported on over the years.
- Jason Bourhill
CAD Concepts, New Zealand
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