Tech Front: Software Slims Composites, Metals Design
For many industries, composites are the material of choice for achieving lightweight, fuel-efficient and strong designs. The challenge going forward for engineers is to take full advantage of the properties of composites by using advanced analysis tools to predict margins of safety, performance, cost, and design for manufacturability (DFM) without adding unneeded weight at each juncture of the engineering design creation and review process.
HyperSizer v6.2 software from Collier Research Corp. (Newport News, VA) is used widely in the spacecraft and aviation industries and includes new modeling capabilities for airframe wing box designs as well as laminate zone and ply-count optimization enhancements to improve manufacturing efficiency. HyperSizer’s capabilities are also appropriate for applications in wind turbine blades, ship hull and superstructures, high-speed railcars, and automobile body components, helping teams move from conceptual design studies through to final validation for aerospace, wind, shipbuilding, railroad and automotive composite applications.
"Composites are booming due to stepped-up fuel consumption efficiency goals," says Craig Collier, president of Collier Research. "This is pushing the movement towards light-weighting. But creation of lighter, stronger designs is limited by many of today’s standard industry practices. Weight is needlessly added because engineers have only a partial view of options. They often overdesign to play it safe."
"It’s a robust analysis tool that allows
us to complete our weight and strength studies in far less time, while finding
optimal ply coverages."
To overcome such drawbacks, HyperSizer targets weight while serving as an independent and neutral data exchange hub for CAD, FEA, and composite software packages. It iterates with FEA solvers, calculates margins of safety, validates failure predictions with test data, and sequences composite laminates for fabrication—avoiding weight growth as designs mature.
"HyperSizer works from preliminary design through flight certification," says Collier. "This gives the engineering team a more wide-open conceptual design space for performing trade studies involving thousands of alternatives. They can find robust solutions that lead to significant weight and cost savings. On average our customers reduce weight by 20%."
"In the past, our designs were often overweight," says Ian Fernandez, former materials and analysis lead on NASA Ames Research Center’s LADEE satellite project. "HyperSizer has enabled our Center to be more competitive in this regard. It’s a robust analysis tool that allows us to complete our weight and strength studies in far less time, while finding optimal ply coverages."
HyperSizer has been used on a wide variety of NASA spacecraft projects including the current Space Launch System (SLS) rocket, previous Ares I and V launch vehicles, the Composite Crew Module, and the metal Orion Multi-Purpose Crew Vehicle. Commercial aviation customers include Boeing, Bombardier, Goodrich, Gulfstream, and Lockheed Martin.
New features and enhancements in HyperSizer v6.2 include:
Discrete Stiffener Modeling—For airframe wing box and fuselage structures, the software automatically identifies in the FEM, skin shell and stiffener beam elements and optimizes their spacings, heights, and laminates.
Laminate Optimization for Manufacturability—An improved, six-step process optimizes laminates (transition zones, ply-count compatibility, ply drops/adds, global ply tracking) while balancing strength, stability, and manufacturability. This leads to fabrication efficiencies and factory-floor cost-savings. ME
For more information on Collier Research and HyperSizer v6.2, go to www.hypersizer.com or phone 757-825-0000.
Chasing titanium parts production for the Airbus 350 and Boeing 787 involves a serious commitment to technology. As part of its most recent $100 million expansion, Aerospace Dynamics International (ADI; Valencia, CA) chose two five-spindle MAG Ti profilers that can deliver more parts per cycle than single-spindle machines and comparable speeds and feeds. "The new MAG profilers, and others like them in our shop, simply make us more efficient and competitive in the global aerospace machining market," explains ADI President and CEO John Cave.
"We can complete up to five parts per setup, and always have the spindles making chips while new workpieces are being set up in another work zone, which minimizes out-of-cut time. In machining titanium, a single-spindle machine is limited to about the same speeds and feeds as our profilers, and even with a fast toolchanger, a single-spindle machine is no match for one that completes five hard-metal parts in the same cycle. We get five parts in the same cycle time that a single-spindle needs for one part. That’s productivity-enhancing performance that we pass on to our customers," Cave says.
The two machines share a 120' (36.6-m) X-axis rail for multipart production advantage in machining titanium components and join two MAG U5 universal machining centers, two MAG boring mills, and MAG’s Freedom eLOG monitoring software. ADI also purchased tooling and applications support from MAG’s Productivity Solutions business to ensure world-class competitiveness and productivity in machining titanium.
"We can complete up to five parts per setup, and always have the spindles making chips while new workpieces are being set up in another work zone."
One of ADI’s specialties is machining large, complex titanium parts for OEMs, including Lockheed Martin, Boeing, Airbus, NASA, and Spirit, among others. The company’s volume has been increasing steadily in recent years, with legacy work on Boeing 737 and 777 and Airbus A380 and A330 programs all increasing in rates, according to Cave. ADI also supports Boeing’s 787 program. "We’re acquiring these profilers for new work—production of complex assemblies for the Airbus A350," he explains. "The work involves a large, complex structural assembly that includes electrical and hydraulic systems. The new profilers are brutes, designed for high metal removal rates with titanium, which further improves our competitive position in pursuing this work."
MAG introduced the Ti profiler in response to surging demand for aerospace titanium parts. The spindle motors are rated 51 kW, with 2523 N•m torque and a speed range of 10–3500 rpm. To apply this much power with stable dynamics, the machines are engineered with a new spindle support housing and an extremely stiff, heavyweight machine structure providing superior damping. The ADI profilers utilize 60-taper tools to support highly efficient roughing and finishing operations. Five six-pocket tool exchangers, located at each end of the work zone, permit five tool exchanges per machine. X-axis motion is powered by rack-and-pinion drives on both rails, while Y and Z axes are driven by large-diameter ballscrews, with a counterbalance and brake on the Z. ME
For more information on MAG, go to www.mag-ias.com
or phone 859-534-4685.
Med Cell Packages
oboDrill Med Cell from Methods Machine Tools Inc. (Sudbury, MA) is a complete pre-engineered, fully-integrated production machining cell that automates loading and unloading of medical device parts. The FANUC RoboDrill machining center is at the core of the system. The Med Cell has full five-axis machining capability and is well-suited for medical machining applications including short-run production of parts in a variety of materials from stainless steel to titanium.
The compact Med Cell is designed for simple installation, fast setups and changeovers, operator safety and production flexibility. Featuring an integrated macro chuck, the Med Cell enables different parts to be mounted on the same universal chuck base for maximum versatility. The Med Cell is easily configured to handle virtually any part that will fit in its 6" (152.4-mm) vise or chuck. The workpiece is pallet-mounted, ensuring that parts remain perfectly aligned when moved through other production operations. The Med Cell incorporates a compact, custom-engineered drop trunnion rotary table that positions the table faceplate close to the RoboDrill table surface, providing increased rigidity and enhanced accuracy.
With a fully integrated FANUC six-axis robot, the Med Cell automates loading and unloading and minimizes or eliminates a long list of production problems. The high-speed six-axis FANUC LR Mate 200iC Robot comes complete with grippers, a teaching pendant, and several easily customizable programs. The package also includes fully-interfaced inbound and outbound conveyors and guarding that are customized to receive the integrated macro chuck, for full lights-out automation.
The heart of the Med Cell is the RoboDrill vertical machining center (VMC), which is designed for years of continuous, full five-axis machining via powerful CAMplete software (optional) for today’s exotic materials and designs. RoboDrill offers a 14-tool (or optional 21-tool) toolchanger, 10,000 or 24,000-rpm spindle, torque to 56 ft-lb (76 N•m) rigid tapping to 5000 rpm (8000 rpm optional), accelerations in X, Y, Z axes to 1.5 g, rapid traverses to 2125 ipm (54 m/min), feed rates to 1181 ipm (30 m/min) with optional 2362 ipm (60 m/min), high-speed reverse tapping, thread milling, 1000 registerable programs, and 54 work offsets. In addition, the industry-standard FANUC 31i control is operator-friendly and easy to use. The Med Cell can also be modified for use in turning applications in conjunction with a Nakamura CNC lathe, also from Methods Machine Tools Inc. An optional graphite machining package is also available, and a vision system can also be added to identify parts of differing sizes. ME
For more information on Methods Machine Tools Inc. go to www.methodsmachine.com or phone 978-443-5388.
This article was first published in the July 2012 edition of Manufacturing Engineering magazine. Click here for PDF.