Abstract: The present disclosure provides a four-dimensional imaging method for structural damage based on a time-invariant characteristic signal. The method first uses a probability statistical modeling method to describe the uncertainty distribution of the amplitude of each sampling point in the signal in the healthy state and the damaged state of the structure, respectively. Then the degree of difference between the two distributions at each point is measured to suppress the influence of the time-varying factor, highlight the influence of damage, and construct a time-invariant characteristic signal. Finally, the time-invariant characteristic signal of the pitch-catch channel is fused by using the guided wave imaging method to further enhance the influence of damage. Based on this, four-dimensional imaging is performed to achieve reliable and accurate location of structural damage.

Abstract: The present disclosure provides a four-dimensional imaging method for structural damage based on a time-invariant characteristic signal. The method first uses a probability statistical modeling method to describe the uncertainty distribution of the amplitude of each sampling point in the signal in the healthy state and the damaged state of the structure, respectively. Then the degree of difference between the two distributions at each point is measured to suppress the influence of the time-varying factor, highlight the influence of damage, and construct a time-invariant characteristic signal. Finally, the time-invariant characteristic signal of the pitch-catch channel is fused by using the guided wave imaging method to further enhance the influence of damage. Based on this, four-dimensional imaging is performed to achieve reliable and accurate location of structural damage.

Abstract: The present invention discloses a Multiple Signal Classification (MUSIC) corrosion monitoring method via excitation beam forming and weighted image fusing. Because damage-related scattering signals are weak and precision of the MUSIC algorithm is affected, the present invention first introduces excitation beam forming and two arrays into the MUSIC method, to enhance scattering signals of corrosive damage and improve their signal-to-noise ratios. Then, the two arrays serve as an excitation array or a sensor array in turn, by assigning weight to fused corrosive damage images of the two arrays, monitoring of corrosive damage in blind zones of the one-dimensional linear arrays is realized. Finally, factors related to the corrosive damage are calculated based on eigenvalues of covariance matrixes of array signals, to determine the depth of the corrosive damage.

Abstract: The present invention discloses a Multiple Signal Classification (MUSIC) corrosion monitoring method via excitation beam forming and weighted image fusing. Because damage-related scattering signals are weak and precision of the MUSIC algorithm is affected, the present invention first introduces excitation beam forming and two arrays into the MUSIC method, to enhance scattering signals of corrosive damage and improve their signal-to-noise ratios. Then, the two arrays serve as an excitation array or a sensor array in turn, by assigning weight to fused corrosive damage images of the two arrays, monitoring of corrosive damage in blind zones of the one-dimensional linear arrays is realized. Finally, factors related to the corrosive damage are calculated based on eigenvalues of covariance matrixes of array signals, to determine the depth of the corrosive damage.

Abstract: The present invention discloses a diode array-based digitized miniature ultra-low-power-consumption impact monitoring system, which belongs to the technical field of aircraft structural health monitoring. The impact monitoring system consists of a miniature sensor array interface, a passive band-pass filter array, a diode array, a digital conversion and management module, an on-board bus communication module, a monitoring data storage module, a self-powering module, and a miniature communication and power supply interface. According to the impact monitoring system, the amplitudes of impact response signals are controlled within a clamp voltage range of diodes by using the diode array, thereby realizing the first-stage digitization; and the second-stage digitization of the impact response signals is realized by using the digital conversion and management module consisting of a miniature field programmable gate array of ultra-low-power-consumption.

Abstract: The present invention discloses a diode array-based digitized miniature ultra-low-power-consumption impact monitoring system, which belongs to the technical field of aircraft structural health monitoring. The impact monitoring system consists of a miniature sensor array interface, a passive band-pass filter array, a diode array, a digital conversion and management module, an on-board bus communication module, a monitoring data storage module, a self-powering module, and a miniature communication and power supply interface. According to the impact monitoring system, the amplitudes of impact response signals are controlled within a clamp voltage range of diodes by using the diode array, thereby realizing the first-stage digitization; and the second-stage digitization of the impact response signals is realized by using the digital conversion and management module consisting of a miniature field programmable gate array of ultra-low-power-consumption.

Abstract: The present invention discloses a method for locating an impact area of a composite structure based on an energy weighted factor, which belongs to the field of structural health monitoring technologies. According to the characteristic that the closest a sensor in an impact occurring sub-area is to the impact position, the most the sensor is affected by the impact, the present invention defines a characteristic parameter of the energy weighted factor, to represent the degree that each sensor is affected by the impact within the entire impact monitoring range, then calculates the degree that each sub-area is affected by the impact within the monitoring range, and finally determines that the sub-area most affected is the impact occurring sub-area.