Image courtesy of Missile Defense Agency
Solution

National Missile Defense, Inflated Fabric Radome for Sea-Based X-Band Radar

United States

Completion

2005
National Missile Defense, Inflated Fabric Radome for Sea-Based X-Band Radar
National Missile Defense, Inflated Fabric Radome for Sea-Based X-Band Radar
National Missile Defense, Inflated Fabric Radome for Sea-Based X-Band Radar

The Sea-Based X-Band Radar (SBX) is a major component of the Ground-Based Mid-Course Missile Defense (GMD). The SBX is a mechanically steerable, phased-array radar antenna mounted on a self-propelled, ocean-going, semi-submersible platform. This advanced X-Band Radar (XBR) is housed within an inflated radome designed to protect the radar from the harsh sea environment and cyclones of the Pacific Ocean. SGH worked with Raytheon and ILC Dover to design the radome. 

 

Scope | Solutions

 

The air-inflated, fabric radome is 120 ft in diameter with a spherical top half and prolate bottom half. The radome fabric is made of vectran fibers and was built by ILC Dover. Working with subconsultants Oceanweather Inc. and CPP Inc., SGH’s completed following:

  • Established design wind conditions and performed wind tunnel tests

  • Characterized the fabric’s nonlinear material properties, including uniaxial and biaxial testing, and determined effects of handling damages and UV exposure on fabric strength

  • Conducted testing to determined creep rupture characteristics of the fabric under sustained loading due to internal pressure combined with wind loading

  • Performed nonlinear finite element analysis of the fabric radome, considering nonlinear material properties and large deflections along with the effects of wind-induced rippling resulting from low shear strength of the fabric

  • Incorporated the results of our analysis and testing into a reliability model, accounting for variabilities in wind loading and material resistance (e.g., degradation, handling damages, stress biaxiality, and sustained loading effects)

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