Abstract: A probability multiply-sum structural damage imaging positioning method and system based on a delay factor includes obtaining optimal excitation frequency and group-velocity theoretical correction function based on numerical simulation of composite laminates; based on optimal excitation frequency, obtaining ultrasonic guided wave response signals of composite laminates in healthy and lossy states and sensor coordinates used for signal collection; performing path screening based on ultrasonic guided wave response signals; obtaining group-velocity correction function based on measured group velocity obtained based on ultrasonic guided wave response signal in healthy state, and calculating actual delay time based on obtained effective path, group-velocity correction function, and sensor coordinates; obtaining damage delay factor based on actual and reference delay time; forming path probability distribution based on damage delay factor, and performing path probability multiply-sum operation to obtain structural

Abstract: A digital, self-diagnosis, sensing intelligent layer integrating active and passive monitoring, including: a capacitance testing unit, configured to charge a to-be-tested piezoelectric transducer by generating a step signal, and determine a transition moment, to obtain a free capacitance value of the to-be-tested piezoelectric transducer; a frequency testing unit, to charge the to-be-tested piezoelectric transducer by generating sinusoidal signals of different frequencies, and detect a resonant frequency according to the transition moment; an active and passive monitoring module, to obtain analog response signals in an active mode and a passive mode, and convert the analog response signals into digital response signals for transmission; and a main control module, to transmit a self-diagnosis result and the digital response signals to a guided wave host. The intelligent layer integrates active damage scanning and passive impact monitoring while implementing self-diagnosis for a piezoelectric transducer state.