COMPOSITES MODELING FOR RADOMES: SHAPING A SOLUTION

As concerns over fuel efficiency increase, lightweighting planes is an ongoing concern — and composites materials are an obvious solution. With their light weight, relatively low cost, electrical transparency, strength and structural stability, today’s innovative composites are revolutionizing the aerospace and defense industry. For example, the latest generation of commercial aircraft from Boeing and Airbus are made up of over 50 percent composites materials.

While composites offer many benefits, they present significant engineering challenges. Material layers must be stacked in different orientations, at varying thicknesses, to ensure structural stability while creating the complex, curving shapes that characterize aircraft. Perhaps nowhere is this challenge more apparent than in designing radomes, the curved weatherproof structures that house antennas. With more than two decades of experience in modeling composites, ANSYS helps leading aircraft engineering teams to overcome the challenge of designing radomes and other composites structures. ANSYS Composite PrepPost (ACP), a module in ANSYS Workbench, enables engineers to import a radome model and perform ply stacking, draping and fiber orientation in an intuitive virtual design space. They can determine where composite layers should start and stop as well as design appropriate transitions between thick and thin material sections.

ACP also allows engineers to evaluate performance of a composites design, assess its structural strength, and identify potential regions of failure. By iterating this process, the team can easily optimize a design that thrives in real-world conditions. ACP is completely integrated into the Workbench platform, enabling aircraft engineers to change the radome’s geometry and then automatically pass the new shape into the solver, eliminating intervention or rework. New in ANSYS 14.5, solid composites geometries can be evaluated as solid 3-D mesh and integrated into ANSYS Mechanical solid assemblies within Workbench, enabling more accurate prediction of material stiffness and strength. This feature complements the existing shell representation capability, and it was designed with the very specific needs of aerospace and defense engineers in mind. New workflows in ANSYS 14.5 make composites design faster and more intuitive. The ANSYS Mechanical suite enables parametric analysis for composites designs, delivering increased speed and insight for mechanical engineers. Teams can perform what-if analysis to quickly gauge the effects of design alterations — for example, changing the fiber orientation, thickness or ply drop-off locations, or even suppressing or including ply stacks parametrically. As aircraft engineers use these features to make refinements, they can look at multiple design points, applying aerodynamic or inertial loads to assess material strength and displacement. They can replicate mechanical impacts created by real-world forces, such as bird strikes or hail, to ensure radome integrity.

Engineers can also incorporate the effects of thermal changes on the design. The integration and flexibility of the entire ANSYS suite allow radome engineers to apply tools such as ANSYS HFSS, industry-standard simulation software for 3-D full-wave electromagnetic field simulation. Used together, the suite helps to ensure the structural strength of a radome design as well as to verify that it delivers high signal-transmission performance — obviously a critical concern in the radome application.

ANSYS Composite PrepPost enables engineers to import a radome model and perform ply stacking, draping and fiber orientation in an intuitive virtual design space.