Advanced composite materials make up most of the wing, fuselage and tail for the Boeing 787 and Airbus A350, plus a high percentage of the primary structures in other major aircraft in development. One look at Boeing and Airbus ideas for future commercial aircraft — blended wing bodies, structures that mimic bones, shape-changing flight surfaces and energy-capturing interiors — and the expectations for composites are clear.
Advanced composite materials are being developed to enable such products, some of which are not feasible with today’s materials. Manufacturing and especially development costs are barriers to such expanded applications, however. One reason: The decades-old building- block approach to certifying composites for use in aircraft requires thousands of costly physical tests.
Replacing at least some of these physical tests with virtual simulations (digital manufacturing) is emerging across the composites manufacturing spectrum as a promising method of documenting the effectiveness of new composite materials, advanced design tools and manufacturing processes faster and more cost-effectively. Few predict that computer-based simulation will eliminate physical testing altogether. But many see a future where simulation and computer-aided analysis play a significantly larger role in streamlining development cycles and reducing costs.
“Simulation tools can guide understanding of uncertainty in design and also how it propagates.”
Flattening the Pyramid
One example of virtual testing’s promise comes from the first spacecraft fuel tank designed to disintegrate upon reentry. The carbon-fiber composites design is made by Cobham Life Support in Westminster, Maryland (USA), for the US National Aeronautics and Space Administration (NASA) Goddard Global Precipitation Measurement Satellite. Thanks in part to extensive use of computer-aided design and testing, Cobham’s development program met all of NASA’s targets: cost, schedule and a host of demanding technical requirements.
Cobham’s process reduced the number of destructive tests by 50%, saving roughly $500,000 over the 38-month program. “Our testing and analysis worked hand-in-hand to improve efficiency,” explained Robert Grande, business manager for Cobham. “We fed real material properties from tests into the models and then used physical testing to validate the results as we iterated the design. Because our test results matched our analytical predictions, from subcomponents to pressure burst and fatigue testing on the full tank, we completed the full qualification by the time we finished the design.”
“Simulation tools can guide understanding of uncertainty in design and also how it propagates,” stated Dr. R. Byron Pipes, John Bray Distinguished Professor of Engineering, Purdue University.
This article is an excerpt, originally published in Dassault Systèmes’ Compass magazine, and was used with permission. Read the full article here.