SIMULIA Community News
March 2016: Exploring the Power of Optimization
Design Engineers Share their Experiences Innovating with the Power of Optimization
What’s it like to put Isight and/or Tosca to work on tackling your design challenges? Can these tools really help you move from solve to innovate? Whether or not you are using either of these SIMULIA portfolio applications yet, you are probably already becoming aware of pressures in your own
workplace to provide deeper insights and think-outside-the box analyses as you strive to produce design ideas that meet your company’s customers’ demands in creative ways. And, of course, to do it all in less time, and more cost-effectively, than ever before. While Abaqus FEA remains at the core of much of what our SIMULIA user community does, there’s so much more you can accomplish these days. And it’s much easier than ever before because tools like Isight and Tosca automate and organize your processes for you on so many levels. You may already be feeling like you could use support in this area: As increasingly sophisticated analysis results pour in, you need to manage your data, capture your processes for reuse, collaborate with your peers—in fact, you need to optimize everything you do. To further explore some examples of optimization at its best, we talked with SIMULIA customers Ford Motor Company and Optimal Device to find out how they are already using the tools and what their plans are for the future. Ford Motor Company has taken an early lead in automotive innovation with their new aluminum truck body. But even in the case of their “everyday workhorse” exhaust manifolds, they are combining Isight, Tosca and an in-house solver into a workflow that lets them imagine manifold geometries in new ways to reduce weight while enhancing performance and durability. Optimal Device provides software training and consulting services with a focus on the medical industry but, as you’ll see, they also apply optimization in other fields in some very creative ways.
FORD MOTOR COMPANY: LIGHTWEIGHTING AN OPTIMIZED EXHAUST MANIFOLD WITH ISIGHT AND TOSCA
While U.S. mileage and emissions standards differ to some extent from those in Europe, American manufacturers are pursuing similar vehicle lightweighting strategies as important routes to help meet ever-tightening government regulations. One example of this is Ford Motor Company’s approach
to optimizing the design, performance and durability of a vehicle exhaust manifold. This cast-steel or -iron component is expected to have a long service life that is certified crack and leak free—despite 800 to 1000° C operating temperatures that can cause Thermal Mechanical Fatigue (TMF) in the form of material degradation, creep, and corrosion.
“A big challenge in exhaust-manifold design is to design one that is lightweight that still allows us to achieve the desired durability while under the harsh thermal and vibration loadings on a firing engine,” says Jerry Hsieh, Durability Technical Expert at Ford.
Real-world testing of an exhaust manifold involves operating a dyno engine at peak exhaust gas temperatures for 10 minutes, cooling it for another 10 minutes, and repeating the cycle until the manifold either fails or passes a vehicle-specific number of hours. “It’s time-consuming to use hardware testing to drive or fix our designs,” says Hsieh. “So using CAE to analytically assess exhaust manifold TMF life is now a required standard at Ford and it has shortened our development time and improved our quality.”
In their quest for the best manifold designs for the many cars and trucks in the Ford fleet, Hsieh’s team uses Abaqus FEA as well as SIMULIA’s Isight (parametric) and Tosca (nonparametric) optimization tools.
When considering the geometry of a particular exhaust manifold, the engineers need to identify those areas that experience the highest temperatures and stress/strain over time. They run a series of CAE analyses: 1-D-Intake-Combustion-Exhaust (ICE) Simulation, 3D CFD exhaust manifold flow analysis, transient exhaust manifold heat transfer analysis, transient exhaust manifold thermal stress analysis, and finally TMF life calculation. Some 28 different internal and external Heat Transfer Coefficients (HTCs) are calculated at seven locations and optimized with Isight’s datamatching module. “This Isight approach improves quality and development time, achieving an accurate match to thermalcouple
measurements,” says Hsieh.
With optimized HTC data in hand, the engineers then transfer these values into Tosca for shape optimization. “When using Tosca, we link our previous Abaqus transient thermal stress analysis with our in-house TMF life calculator (called ‘HotLife’) to identify those areas of low fatigue life,” says Hsieh. “We let Tosca shape optimization ‘patch’ only those areas that need it with a bit more material.” This technique avoids “overbuilding” a manifold and adding excess weight.
The Ford team finds that Abaqus, Isight and Tosca work well together to help them meet their design targets and program timing goals. Says Hsieh, “With Isight and Tosca, we have shortened development time and improved quality and durability and reduced weight at the same time.”
OPTIMAL DEVICE: USING TOSCA TO DESIGN FOR DIFFERENT MANUFACTURING PROCESSES
Rob Stupplebeen’s company name, Optimal Device, reflects his enthusiasm for the power of optimization. A longtime Abaqus user whose consulting and training team focuses on medical devices, he has employed SIMULIA’s Isight, Tosca and Simpoe to help design everything from ballistic face
shields for the military to precision optics for space telescopes. He also likes to showcase the occasional “goofy” design just for fun. A former high-school lacrosse player, and now a coach for his eight-year-old son, Rob recently began a usecase blog about lacrosse-stick head design—that he is turning into a presentation for the upcoming Science in the Age of Experience event in Boston. Stupplebeen began by comparing the equipment he played with in the past to the sticks in use today. “When looking at my old lacrosse head, I saw noticeable differences between it and the more modern ones,” he says. “It had clearly evolved from my time, as an injection-molded industrial-design with manufacturing constraints, to the current engineering-driven design with a truss structure of varying angles and sizes. This kind of organic truss structure is essentially what topology optimization evolves towards.”
Starting from the NCAA rules regarding stick dimensions, Stupplebeen created a CATIA model of the head component with the largest permissible amount of material. Then he brought the drawing into Abaqus. “Once you have that working FEA model it can include nonlinearities because of Tosca’s unique abilities to handle nonlinear topology optimization,” he says.
Work went quickly, Stupplebeen reports. “From opening up the rule book to having a viable design on-screen only took a couple days and I produced something remarkably similar to recent commercially available injection-molded designs,” he says. “I also was able to do it all on my own. Topology optimization provides a huge amount of power and intuition into a design without a lot of labor at your end.”
MANUFACTURING OPTIONS: INJECTION MOLDING OR 3D PRINTING?
Stupplebeen looked at two manufacturing solutions for his optimized design, injection molding (which he could simulate with SIMULIA’s Simpoe-Mold software) and additive manufacturing in a 3D printer.
“Design has always been influenced at best and restricted at worst by the manufacturing technique,” says Stupplebeen. “Topology optimization naturally creates organic designs that can be difficult to manufacture with traditional techniques. These are ideally suited to the minimal design constraints
offered by additive manufacturing. However, Tosca can also provide optional constraints such as demolding control, which is especially useful for injection molding.”
Regardless of final manufacturing method, Stupplebeen says, “Tosca is as close to magic as you can get with simulation.”
POWERING INNOVATION WITH OPTIMIZATION
We hope these examples have helped you understand the huge potential for product and process improvement that optimization with Isight and Tosca offer you. The journey from solve to innovate has already begun in many companies. And it is more accessible—to design engineering shops of all sizes—because the tools are easier to use than ever before. Getting a firm grip on the complexity of today’s product design process is how you move forward and become an employee who is more valuable to his or her company. Being empowered in this way will free you to innovate even more.
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