Expert Interview: Altair’s Ravi Kunju On Simulation Software For 3D Printing
20 January 2020
Achieving a simpler and faster design preparation workflow has been an ongoing quest within the 3D printing industry. Designing for Additive Manufacturing is a complex process, with its unique challenges and opportunities.
Therefore, it requires relevant tools to enable engineers to take full advantage of the design flexibility of AM. Altair is one such company that develops these solutions. Altair is a global technology company that provides software and cloud solutions in the areas of product development, high-performance computing and data analytics.
In this week’s Expert Interview, we speak with Ravi Kunju, Sr. VP Business Development & Strategy, Simulation-Driven Design, at Altair. With Ravi, we learn more about the recently launched Altair Inspire Print3D software tool, the current state of simulation software for 3D printing, and explore some of the exciting AM applications enabled by Altair solutions.
Could you tell us a bit about Altair and the challenges you’re solving?
We’re a global technology company that provides software and cloud solutions in the area of product design, product development, high-performance computing and also data analytics.
Our vision, and what we’ve been doing in the 30+ years we’ve been in business, is to transform product and business decision-making through our simulation technology, our data analytics solutions, and also our industry-leading design optimisation solutions.
I’m responsible for the simulation-driven design products for Altair.
You’ve recently launched Altair Inspire Print3D software. Could you explain the different software solutions you provide?
Altair Inspire Print3D is just one of many solutions we offer.
Altair has been a leader in the area of optimisation for many years. We have customers using our optimisation technology to create their designs for all kinds of manufacturing methods – whether it’s sheet metal forming, casting, extrusion or injection moulding. They also use our technology to better understand the performance requirements and create generative designs specifically for a manufacturing process.
In that context, it’s important to understand the two ends of the spectrum. One is what drives the design and the other is what happens once you have a design that you want to manufacture. These elements come together on our platform.
One of the things we’ve done with our Inspire platform is to bring the simulation-driven design process upfront and make it very easy for the designers to understand and drive designs, while being completely cognisant of the manufacturing process.
Since it is not prudent to separate the manufacturing process from the design requirements, we’ve put all of them in one single environment through our platform.
So, Inspire Print3D is focused on two things. One is, under the Inspire platform it allows our users to generate designs specifically for any AM process; using specific manufacturing rules (constraints) that drive design to meet the manufacturing process.
Second is to take all the performance requirements and combine them, and use advanced numerical methods to automatically generate a design for either selective laser melting (SLM) or fused deposition (FDM) or binder jetting (MJF) or Wire Arc Additive Manufacturing (WAAM).
So, the Print 3D module allows you to not only generate the design but also helps in virtually validating the performance of the new design that you have created.
The first release of Print3D allows the user to simulate the selective laser melting process. An advanced thermo-mechanical simulation is embedded in this environment to evaluate any manufacturing issues that may arise during 3D printing like distortion, high stresses and ruptures associated with them. The designers can generate the design and add in the support structures, and fix any of the problems all within one single environment before going to print.
The biggest benefit we see is that today, if you look at what the customers are doing in AM, they usually have a suboptimal approach for creating an optimal design. Additionally, once they have come up with a design, they’ll try to put in support structures to ensure they’re able to print the part and then discover later that they have issues. For all these steps there are separate software solutions.
Altair eliminates all that by enabling users to design and evaluate a part within one single environment.
It is well known, that around 45 per cent of the cost associated with metal AM today can be attributed to support removal. Effectively using our design rules (constraints) allows end-users to create designs that have minimal or zero supports. We also allow users to create support structure, understand its effectiveness through the thermo-mechanical simulation; wherein we can simulate the build, cooling, support removal and predict the subsequent springback and associated distortion and avoid downstream failures.
That’s what Inspire Print3D does: it allows end-users to ideate, evaluate and validate your design, in one single environment. Altair Inspire thus helps our end-users to create lightweight and high-performing designs while simultaneously improving productivity.
How would you describe the current state of design, simulation and topology optimisation software for AM?
Altair has been the leader in topology optimization and generative design for a number of years, not just for additive, but for all manufacturing processes. We have more than 5,000 customers using our products on a daily basis to create optimal designs.
But not all generative design tools are alike. We have the best numerical methods to solve key problems and we are the only ones who take different performance criteria, load cases together and combine them with manufacturing constraints, to create designs that are very specific to that design process.
In order to drive and generate a design, there are two things that need to be understood well: performance requirements and the manufacturing process.
For example, if you’re doing metal casting and you don’t want to have any cores, that are sacrificial and expensive, or, if you want to create a shape without undercuts for efficiently removing patterns from the die cavity; the right manufacturing constraints have to be combined with performance manufacturing to generate lightweight design.
There are lots of tools out there that can generate an organic design, and people tend to think that this is all that is needed. But, in fact, that is just the beginning, because you want to make sure you understand the manufacturing processes and what the optimal design should be for a given process. Just generating an optimal shape is not sufficient if you don’t understand the manufacturing requirements.
In the generative design space, there are many numerical approaches that you can use; for example, you can perturb some design variables and generate thousands of designs and then say, ‘I’m going to vary all these different shapes and sizes and that will give me a thousand designs, evaluate each one and then identify the best one.’ This can be suboptimal, time-consuming and expensive for certain component level optimization. You may not get a good solution.
On the simulation side today, AM has been predominantly confined to prototyping. But Altair has been on a quest to help our customers transform the process to make more than one-off parts. Can we explore the other methodologies like binder jetting? Can we explore hybrid casting, where you do sand printing and then pour castings into a sand mould? Can we explore some of these options to convert your capability into capacity?
That’s been our quest to deeply understand the unique manufacturing requirements. Today we are the leaders for creating high-performance lightweight parts, as well as tooling and assembly, using the latest design for manufacturing methods.
Are you able to talk about some of the applications that have been achieved, in part thanks to your design software?
The earliest adopters were the satellite and aerospace companies, because they didn’t have large volumes, but they needed highly optimized and lightweight designs. We designed a telescope bracket and other brackets with EOS for EADS where complex loads came into play.
We’re also working with automotive companies, including the likes of BMW, Ford, GM and a plethora of other companies around the world, that are exploring additive manufacturing as a viable option for prototyping.
If I slice it down, we see not only direct 3D printing, but an abundance of hybrid manufacturing as well, where traditional manufacturing is combined with additive. What I mean by that is, for example, sand 3D printing of cores and moulds for casting.
The second area is moulds for plastic injection moulding. It is important that the mould assembly that forms the cavity does not separate during the pressurization cycle inducing flash that needs to be removed. The entire mould can be structurally optimized using generative design to maintain the integrity under the loads.
In addition to the structural optimisation, we can also optimise for heat extraction with conformal cooling lines that wrap around regions requiring rapid cooling. Such organic structures are ideal for 3D Printing.
We work with PROTIQ on these examples, where you can go almost from 9 seconds cycle time to 3 seconds. So, if you’re making a million parts a day, you can then make 3 million parts a day. It means that you can increase your productivity threefold, optimising the mould for the injection moulding process.
We also work with the robotics industry, which has numerous applications where design optimisation and 3D printing are used for robotic end-of-arm grippers. The grippers tend to wear off very quickly and so they need to be replaced immediately to prevent assembly line disruptions.
For extremely large structures, we’ve recently collaborated with MX3D on a 3D-printed robotic arm. MX3D is a 3D printing company, which uses proprietary wire arc-based technology to produce large metal structures.
Our software-enabled MX3D to optimise the robotic arm design to reduce more than half of the original weight, while considering printing constraints. For this project, our engineers used Generative Design Customisation to come up with the most efficient shape for the 3D-printed robot arm.
There are also many defence applications that can benefit from 3D printing. For example, if part of a combat vehicle breaks, you want to be able to print this part locally, right away, without having to wait for a replacement part to arrive. This is especially the case for legacy parts that you may not have drawings for.
Our solutions are used in the field of medical 3D printing as well. For example, Andiamo, an orthotic company, is using 3D printing to create better-fitting orthotic devices. The traditional way to make an orthosis is by wrapping a limb of a torso in plaster, which is then cut off and sent for manual fabrication.
Andiamo‘s process eliminates the need for plaster casts, instead starting with a digital 3D scan of the body, creating a highly accurate model to start designing around. The process also involves numerous simulations to guarantee a perfect fit for a child.
We’re also seeing an increased interest in 3D printing processes like binder jetting. We’re working with some of our partners in this space, like Desktop Metal and ExOne. We presented binder jetting applications at Formnext, where we walked through the whole process of creating a bike bracket with FDM, SLM, Hybrid-Casting and binder jetting process.
Looking at the industry more generally, what do you see as some of key developments for 2020?
The industry is moving very fast. Whenever I go to AM events, it’s clear that the number of printer manufacturers and materials suppliers is almost doubling year on year. With the competition increasing, I’m very positive that the cost is going to be reduced, which is a big deterrent on the additive manufacturing side right now.
The increasing number of players is probably going to help the end-consumer.
Look at the dental industry, for example. It is one of the most mature, because if a consumer wants to get a new crown fixed, their dentist simply takes a scan of the tooth and sends the scan to be printed in 2-3 days. That cycle needs to be achieved in other industries as well. And that’s what everybody will continue to strive towards in 2020.
Are there any challenges that you think still need to be overcome in order to further accelerate the adoption of 3D printing?
There are a number of challenges which are intertwined with each other.
Number one is cost. The cost is obviously related to the size of the part and the volume of production which determine what type of manufacturing method should be used. Even within additive you might want to go, for example, either with selective laser melting or with metal binder jetting.
The second aspect is certification. How are we able to certify a part depending on whether the part is load-bearing part or a safety-critical part? And what is the level of repeatability?
Today, the challenge is that we can’t control the cost and have low repeatability. If a part is printed in a particular printer, can one achieve the same specifications if that part is printed by a different printer and in a different location? What are the odds that the parts will behave exactly the same? That results in a challenge of being able to accurately model the physics that’s going on at the micro-level.
This raises the question of whether users can be confident that the final part can be printed consistently across different platforms and locations.
There’s so much work that needs to be done in terms of establishing industry-wide standards and material qualification. Materials suppliers, printer manufacturers, software providers – everybody has to come together to establish certain standards in terms of what are acceptable tolerances for lightly loaded, or heavily loaded safety-critical parts; in terms of meeting internal porosity and/or external surface quality.
If you look at history, whether it’s casting, forging or sheet metal, over the years they’ve all had an association linked to them, like American Foundry Society, for example. There are many organisations that are dedicated to bringing everyone together and creating standards. Today, the AM market is exploding in all areas, but eventually, it all needs to come together to collectively create standards and ensure that each and every industry player is on the same page.
Finally, what does the year ahead hold for Altair?
We will continue to develop more simulation solutions for our users. As for the additive manufacturing processes, we’ll continue to develop solutions that help technology users to validate the process and understand the uncertainties that go along with that.
Ultimately, we’re focused on three main pillars: understanding performance, creating a design by combining two things; performance, and the manufacturing process itself. They all have to go hand in hand, and we will continue on our mission to help our customers validate performance and the manufacturing process as accurately as possible to drive the designs.
We’ll continue to combine physics with high-performance computing and data. We have to put all of them together, because some problems you can solve by understanding the physics and some of them you have to solve with machine learning. We’ll strive to combine all of the technologies we’re developing to make things more efficient and profitable for our customers, with an end-goal of helping them to make better decisions and better performing products.