Optical fiber sensor network and method for monitoring structural health of composite cryogenic liquid hydrogen fuel tank

A fiber optic sensor network and a method for monitoring the health of a composite cryogenic liquid hydrogen fuel tank (1), the method comprising the steps of: a) determining a permeability curve k = f (t) for a material configuration as a function of a usage condition and determining a critical k value for the material configuration, b) performing actual use test on the box (1) with specific material configuration: continuously measuring the following parameters: temperature distribution inside the inner box, temperature distribution inside the middle chamber, temperature distribution on the outer box, strain at multiple positions of the box, and pressure inside the box and inside the middle chamber by optical fiber sensors integrated in the network; the change and correlation of the measurement parameters along with the use time are analyzed; and determining a threshold level of microcracks and estimating the penetration state of the tank (1), comparing k with a critical k value in order to make a decision