An elastic matrix determination method for a laminated iron core, which can optimally determine a shear modulus in two planes including a laminating direction of the laminated iron core included in an elastic matrix in a constitutive equation representing a stress-strain relationship used for vibration analysis, and also provided is a vibration analysis method. When performing a vibration analysis of a laminated iron core formed by laminating steel sheets using a constitutive equation representing a stress-strain relationship in a matrix representation, a shear modulus in two planes including a laminating direction of the laminated iron core included in an elastic matrix in the constitutive equation is determined depending on an average tightening pressure in the laminating direction of the laminated iron core.

A method for determining a quality of a friction stir welded seam is described. The method involves applying an impact to a welded plate and comparing its damping capacity with the damping capacity of a geometrically equivalent defect-free plate. Damping capacities that differ by a small percent difference indicate that the welded plate is also defect-free. This method is particularly advantageous when dealing with small defects, which produce miniscule changes in natural frequency which may not be measureable.

A method for monitoring a pantograph. The method includes acquiring an impulse response of the pantograph, extracting a natural frequency and a damping coefficient of the pantograph from the impulse response, obtaining a similarity factor of a plurality of similarity factors, and detecting a fault in the pantograph from the plurality of fault types based on the plurality of the similarity factors. Acquiring an impulse response of the pantograph includes generating the impulse response by tapping the head of the pantograph and recording the impulse response utilizing a recording equipment.

A defect detection device 10 is provided with: a laser light source 11 for irradiating laser light to a measurement region R of a surface of an inspection object S; a laser light source control unit 15 for controlling the laser light source so as to cause laser light to be outputted continuously or quasi-continuously for a time longer than a period of vibration generated in the inspection object; an interferometer (speckle shearing interferometer 14) for generating interference light in which reflected light of the laser light reflected in the measurement region and reference laser light emitted from the laser light source 11 interfere; a detector (image sensor 145) for detecting the intensity of the interference light for each point in the measurement region R; a phase shifter 143 for shifting the phase of the reflected laser light or the reference laser light; an integrated intensity pattern determination unit 16 for obtaining an integrated intensity obtained by integrating the intensity for each point over an integration time longer the period of the vibration in three or more phases, the phase being shifted by the phase shifter 143 into three or more different phases; an interference degree distribution generation unit 17 for obtaining the distribution of the degree of interference based on the integrated intensity obtained in each of the three or more phases for each point; and a defect detection unit 18 for detecting a defect in the measurement region R based on the distribution of the degree of interference in the measurement region R.

Employing methodologies and systems to detect damage initiation and growth inside a composite material (matrix cracking, delamination, fiber break, fiber pullout, etc.) wherein damage produces high-frequency acoustic emission (AE) waves that are transported to recording sensors along with relatively lower frequency waves representing the flexural deformation of the impacted composite structure.

According to one embodiment, a structure evaluation system according to an embodiment includes a plurality of sensors, a position locator, a corrector, and an evaluator. The plurality of sensors detect elastic waves generated from a structure. The position locator locates the position of a generation sources of a plurality of elastic waves on the basis of the plurality of elastic waves detected by the plurality of sensors. The corrector corrects information based on the position locating performed by the position locator using a correction value set in correspondence with an impact. The evaluator evaluates a deterioration state of the structure on the basis of the corrected information.

In a wedge looseness diagnosis which is performed by striking wedges of a rotary electric machine, a variation of a wave form of a strike sound is reduced with respect to a variation of an amount of looseness of the wedges, and it is difficult that a slight difference of the amount of the looseness of the wedges is discriminated, so that the wedges are struck by a strike portion in a state where the wedges are pressed by a pressure portion which presses the wedges, and a strike sound at a high frequency is reduced, whereby an amount of a variation of magnitude of the strike sound is enlarged with respect to a valuation of the amount of the looseness of the wedges, and the amount of the looseness of the wedges is judged in accordance with the strike sound which is obtained by a strike sound measuring portion.

Disclosed herein is a detection assembly for detecting kissing bonds in a bonded joint of a part. The detection assembly comprises an electromagnetic shockwave generator that is configured to generate an electromagnetic shockwave through a target portion of the bonded joint. The electromagnetic shockwave has an intensity sufficient to induce a separation of a kissing bond in the target portion of the bonded joint and insufficient to induce a separation of a healthy bond, adjacent the kissing bond, in the target portion. The detection assembly also comprises an ultrasonic sensor that is configured to generate a transmitted ultrasonic pulse, direct the transmitted ultrasonic pulse into the target portion of the bonded joint, and receive a received ultrasonic pulse from the target portion of the bonded joint in response to the electromagnetic shockwave generator generating the electromagnetic shockwave through the target portion of the bonded joint.

A system for non-destructive testing of a bond condition of concrete beams reinforced by steel rods is described. The system includes a transducing transmitter, a transducing receiver, and an ultrasonic pulse generator configured to generate drive signals for the transducing transmitter and receive a plurality vibrational waves at the transducing receiver. The system further includes a computing device including a measurement circuit configured to record a transit time for each vibrational wave and divide a distance between the transducing transmitter and the transducing receiver by the transit time to determine a pulse velocity of each vibrational wave, a comparison circuit configured to identify a highest pulse velocity of the vibrational waves and compare each highest pulse velocity to a first reference pulse velocity, and a decision circuit including an artificial neural network configured to identify a compromised bond condition around a steel rod.

Systems and methods are provided for monitoring the structural integrity of a vehicle. In particular, systems and methods are provided for using transducers positioned at various location in and on a vehicle to measure parameters related vehicle structural health. In various implementations, the integrity of the vehicle frame and the integrity of the vehicle body are monitored using a multi-axis accelerometer and/or microphone. The use of transducers for monitoring can replace time-consuming and expensive manual inspections.