Inflatable Habitat Structural Health Monitoring via Embedded Fiber Optic Sensors

Abstract

Inflatable structures present a novel solution to high volume-to-weight habitation for future space missions. Structural health monitoring (SHM) of flexible softgoods materials cannot be achieved with many traditional techniques. Fiber optic sensors that measure strain every 0.65 mm along the fiber have been embedded in Vectran webbing to measure strain profiles, gradients, and anomalies within these flexible load-bearing structures. The sensors directly address the two leading failure modes of inflatables: creep and micro meteoroid impact. Fiber optic data were collected during creep tests of an individual strap and during a 1.5-month creep test of a 1/3-scale inflatable at NASA Johnson Space Center culminating in a burst. Distributed strain datasets from the embedded fiber optics were compared with photogrammetry/digital image correlation (DIC) results. System integration studies detailing how the sensing system could be included in future space deployments of inflatable habitats for increased reliability is also presented.