Abstract: Methods of operating an interrogation system that has a plurality of patches attached to a host structure. Each patch is capable of generating a diagnostic wave and/or developing a sensor signal in response to the diagnostic wave. In each method, a Euclidean undirected graph is generated by forming a plurality of paths; wherein each path connects two of the patches and the length of the path is shorter than a preset limit. Then, a directed graph or network is generated by assigning a propagation direction of the diagnostic wave to each path. Structural condition index (SCI) values are measured by use of the directed graph and, based on the SCI values, the host structure is scanned for anomalies. The directed graph is reconfigured to determine the shape and location of the anomalies.

Abstract: Systems, methods and recordable media for prognosticating a structural condition. A method for prognosticating a structural condition by use of a network having a plurality of diagnostic network patches (DNP), each of the patches being able to operate as at least one of a transmitter patch and a sensor patch, includes the steps of: (a) causing at least one of the patches to emit a transmitter signal and a portion of the other patches to receive a set of sensor signals at a point in time; (b) repeating the step (a) to receive multiple sets of sensor signals at multiple points in time, respectively; and (c) prognosticating, based on the multiple sets of signals, a structural condition of a host structure of the network at a target point in time.

Abstract: Systems, methods and recordable media for identifying damage in a structure. A method includes the steps of: obtaining a plurality of damage index values for a network coupled to the structure, wherein each of the damage index values is a quantity to be affected by damage in the structure; generating a distribution of damage index value over a surface using the obtained damage index values; and identifying the damage by analyzing the distribution.

Abstract: Systems, methods and recordable media for generating tomographic images to monitor structural health conditions. A method includes the steps of obtaining a plurality of damage index values for a network that is coupled to a host structure and has a plurality of diagnostic network patches (DNP), generating a distribution of damage index value over a surface using the obtained damage index values, and formatting the distribution as at least one tomographic image. Each of the patches is able to operate as at least one of a transmitter patch and a sensor patch. The damage index values is a quantity to be affected by damage in the host structure or associated with signals generated by the patches in a response to an impact on the host structure.

Abstract: Systems for diagnosing/monitoring structural health conditions of objects. The system, which monitors structural health conditions by use of a plurality of patch sensors attached to an object, includes at least one bridge box. Each of the patch sensors is capable of at least one of generating a wave upon receipt of an actuator signal and developing a sensor signal in response to the wave. The bridge box includes: a switch array module that has a plurality of relay switches; and a signal condition module, wherein the plurality of relay switches are operated to establish a channel between a selected one of the patches and the signal condition module.

Abstract: Methods and recordable media for monitoring structural health conditions. The present invention provides a method for interrogating a damage of a host structure using a diagnostic network patch (DNP) system having patches. An interrogation module partitions the plurality of patched in subgroups and measures the sensor signals generated and received by actuator and sensor patches, respectively. Then, a process module loads sensor signal data to identify Lamb wave modes, determine the time of arrival of the modes and generate a tomographic image. It also determines distribution of other structural condition indices to generate tomographic images of the host structure. A set of tomographic images can be stacked to generate a hyperspectral tomography cube. A classification module generates codebook based on K-mean/Learning Vector Quantization algorithm and uses a neural-fuzzy-inference system to determine the type of damages of the host structure.

Abstract: Interrogation systems for monitoring structural health conditions. An interrogation system includes at least one wave generator for generating a wave signal and optical fiber sensors applied to a structure. The interrogation system also includes at least one electronic module for generating an input sensor signal and sending the input sensor signal to the optical fiber sensors. Each optical fiber sensor impresses the wave signal onto the input sensor signal to generate an output sensor signal that is frequency shifted from the input sensor signal. The electronic module generates an information signal in response to the output sensor signal. The interrogation system also includes a signal processing unit and a relay switch array module that has relay switches. Each relay switch relays the information signal to the signal processing unit and the signal processing unit generates a digital sensor signal that is subsequently sent to a computer.

Abstract: Apparatus for monitoring structural health conditions of structures. The apparatus includes a piezoelectric device that has a bottom cover plate, piezoelectric rings concentrically disposed with respect to an axis and positioned on the bottom cover plate, and concentric filler rings made from an electrically insulating material. Each of the piezoelectric rings is interposed between two adjacent filler rings. The piezoelectric device also includes electrical connection means for communicating electrical signals to the piezoelectric rings and a top cover plate that is positioned over the piezoelectric rings and filler rings. The electrical connection means are operative to transmit electrical signals that cause one or more of the piezoelectric rings to generate waves or transmit electrical signals developed by one or more of the piezoelectric rings in response to the waves.

Abstract: Systems for monitoring structural health conditions of objects. Each system includes patch sensors attached to an object, wherein each patch sensor is capable of generating a wave upon receipt of an actuator signal and developing a sensor signal in response to the wave. The system includes a tree structured relay unit that has a root node and at least one lower level node that includes at least one leaf node connected to the patch sensors. The lower level node includes switches, wherein the switches are operated to establish a channel between the root node and a selected one of the patch sensors and wherein actuator signal or sensor signal is transmitted through the channel. The sensor signals are analyzed to monitor health conditions thereby prevent catastrophic failure.

Abstract: Sensors and systems for monitoring structural health conditions. The present invention provides a device for monitoring structural health conditions including a dielectric substrate, a piezoelectric device for actuating and/or sensing Lamb waves, a molding layer deposited over the piezoelectric device, a cover layer deposited over the molding layer and a hoop layer surrounding the piezoelectric device and being attached to the substrate. The device further includes an optical fiber coil sensor attached to the dielectric substrate, where the coil sensor has a rolled optical fiber cable and a coating layer applied to the rolled optical fiber cable. The present invention also provides a diagnostic patch network that includes a plurality of patch sensors attached to a host structure and a bridge box connected to the patch sensors. The bridge box sends information of structural health conditions to and receive power from a ground control system using a wireless communication technique.

Abstract: Methods of operating an interrogation system that has a plurality of patches attached to a host structure. Each patch is capable of generating a diagnostic wave and/or developing a sensor signal in response to the diagnostic wave. In each method, a Euclidean undirected graph is generated by forming a plurality of paths, wherein each path connects two of the patches and the length of the path is shorter than a preset limit. Then, a directed graph is generated by assigning a propagation direction of the diagnostic wave to each path. Structural condition index (SCI) values are measured by use of the directed graph and, based on the SCI values, the host structure is scanned for anomalies. The directed graph is reconfigured to enhance accuracy in determining the shape and location of the anomalies.

Abstract: Sensors and systems for monitoring structural health conditions. The present invention provides a device for monitoring structural health conditions including a dielectric substrate, a piezoelectric device for actuating and/or sensing Lamb waves, a molding layer deposited over the piezoelectric device, a cover layer deposited over the molding layer and a hoop layer surrounding the piezoelectric device and being attached to the substrate. The device further includes an optical fiber coil sensor attached to the dielectric substrate, where the coil sensor has a rolled optical fiber cable and a coating layer applied to the rolled optical fiber cable. The present invention also provides a diagnostic patch network that includes a plurality of patch sensors attached to a host structure and a bridge box connected to the patch sensors. The bridge box sends information of structural health conditions to and receive power from a ground control system using a wireless communication technique.

Abstract: Sensors and systems for monitoring structural health conditions. The present invention provides a device for monitoring structural health conditions including a dielectric substrate, a piezoelectric device for actuating and/or sensing Lamb waves, a molding layer deposited over the piezoelectric device, a cover layer deposited over the molding layer and a hoop layer surrounding the piezoelectric device and being attached to the substrate. The device further includes an optical fiber coil sensor attached to the dielectric substrate, where the coil sensor has a rolled optical fiber cable and a coating layer applied to the rolled optical fiber cable. The present invention also provides a diagnostic patch network that includes a plurality of patch sensors attached to a host structure and a bridge box connected to the patch sensors. The bridge box sends information of structural health conditions to and receive power from a ground control system using a wireless communication technique.

Abstract: Sensors and systems for monitoring structural health conditions. The present invention provides a device for monitoring structural health conditions including a dielectric substrate, a piezoelectric device for actuating and/or sensing Lamb waves, a molding layer deposited over the piezoelectric device, a cover layer deposited over the molding layer and a hoop layer surrounding the piezoelectric device and being attached to the substrate. The device further includes an optical fiber coil sensor attached to the dielectric substrate, where the coil sensor has a rolled optical fiber cable and a coating layer applied to the rolled optical fiber cable. The present invention also provides a diagnostic patch network that includes a plurality of patch sensors attached to a host structure and a bridge box connected to the patch sensors. The bridge box sends information of structural health conditions to and receive power from a ground control system using a wireless communication technique.