Abstract: A fastener health monitoring system includes a structure including a first component and a second component, one or more fasteners securing the first component to the second component, and an optical fiber arranged adjacent to the one or more fasteners. The fiber is configured to detect strain on the structure from the one or more fasteners. Strain patterns are derivable from sensed data from the optical fiber, and any deviation in strain value greater than a threshold value at a particular fiber position along the optical fiber is indicative of a missing, damaged, or loosened fastener amongst the one or more of fasteners corresponding to that particular fiber position.

Abstract: In a general aspect, an optimization problem is solved using a hybrid computing system. A classical processor unit receives a first data structure that represents the optimization problem. The classical processor unit executes a branch-and-bound process on the first data structure to generate values for a first subset of elements of a solution to the optimization problem. A second data structure is generated based on the first data structure and the first subset of elements. The second data structure represents a reduced version of the optimization problem. A quantum processor unit and a classical processor unit are used to execute a quantum approximate optimization algorithm (QAOA) on the second data structure to generate values for a second subset of the elements of the solution to the optimization problem. The first subset and second subset are combined to obtain the solution to the optimization problem.

Abstract: A fastener health monitoring system includes a structure including a first component and a second component, one or more fasteners securing the first component to the second component, and an optical fiber arranged adjacent to the one or more fasteners. The fiber is configured to detect strain on the structure from the one or more fasteners. Strain patterns are derivable from sensed data from the optical fiber, and any deviation in strain value greater than a threshold value at a particular fiber position along the optical fiber is indicative of a missing, damaged, or loosened fastener amongst the one or more of fasteners corresponding to that particular fiber position.

Abstract: A core-stiffed composite structure includes a plurality of bonded layers forming the core-stiffened composite structure, a fiber optic conductor embedded between two of the plurality of bonded layers, the fiber optic conductor including a terminal end, and a protective box embedded in the core-stiffened composite structure and bonded to one or more of the plurality of bonded layers, wherein the terminal end of the fiber optic conductor projects into the protective box.