Fixing device comprising a fixing member provided with a bearing head, a sensor provided with a detector of the mechanical force to which the fixing member is subjected, the detector being mounted in contact with the fixing member, and a connecting component which is electrically connected to the sensor, which is configured to transmit a measurement of a mechanical force provided by the sensor and which is mounted on the fixing member, the fixing member comprising a body which is mounted on the bearing head and which extends along a longitudinal axis protruding from the bearing head.

A looseness detection sensor for detecting looseness of a bolt for fixing a component, including: a resonance unit arranged adjacent to a head portion of the bolt and made of an insulating material confining a high-frequency signal input externally; and a conductive member in conduction with the component across the resonance unit, wherein the conductive member is a cap put on the head portion of the bolt and includes a protrusion contacting a surface of the component.

An ultrasonic wave propagation member, which is able to improve durability while ensuring measurement performance, is provided with an ultrasonic wave propagator including a first contact surface coming into contact with an measurement target, and a second contact surface provided opposite to the first contact surface and coming into contact with a fore end surface of an ultrasonic probe; and a holder holding the ultrasonic wave propagator and including a third contact surface coming into contact with the measurement target on a radially outer position than the first contact surface, wherein the ultrasonic wave propagator is softer than the holder.

A method for determining the state of at least one sensor whose mechanical behaviour is nonlinear as a function of the amplitude of the pressure exerted against the sensor, the sensor and an electromechanical transducer being able to be coupled to a support, the method comprising the steps of: applying an electrical signal at a first amplitude to the terminals of the first electromechanical transducer, and determining a first set of values of a parameter characteristic of the electrical impedance of the first electromechanical transducer in response to the application of the electrical signal; applying the electrical signal at a second amplitude to the terminals of the first electromechanical transducer, and determining a second set of values of the parameter characteristic of the impedance; measuring a deviation between the first set of values and the second set of values; determining a state of the sensor as a function of the deviation between the first set of values and the second set of values.

In the present disclosure, embodiments including a system, device and methods are disclosed for accurately measuring the strain or extension of a fastener that occurs as the nut on the fastener is tightened and the fastener is put under load. The measurement technique is based on measurement of the time for an ultrasonic wave generated on one end of the fastener to travel a round trip through the fastener. As the fastener is tightened, the applied stress causes an associated increase in length. This length can be determined from a measurement of the increase in transit time. In various embodiments, the disclosed device and method uses laser ultrasonic testing (LUT), in which a pulsed laser generates the ultrasonic wave and a type of laser vibrometer detects the wave when it returns to the position of generation following a combination of longitudinal wave reflections and a mode conversion to a shear wave.

A method for checking the tightening tension of at least one fastening bolt for fastening at least two aeronautical parts, wherein it includes the steps consisting in mounting a centring device on a head of a screw of the bolt, the centring device including an aperture aligned with an axis of the screw; engaging one end of a sensor in the aperture of the device until this end is in contact with the head of the screw; checking at least one physical parameter of the bolt by the sensor, this parameter being representative of the tightening tension of the bolt; then removing the centring device.

The invention relates to a solution for how to measure the strain in a washer mounted in a bolt assembly comprising a bolt, nut and washer. The invention concerns a strain measuring washer assembly comprising a plate shaped washer body, sound emitting means and sound detecting means, and a method for using such.

The present invention discloses a method and system for detecting the fastening state of a fastening structure which fixes structural elements. At least a first vibration sensor is mounted on a first structural element for collecting vibration data of the first structural element. At least a second vibration sensor is mounted on a second structural element or on the fastening structure for collecting vibration data of the second structural element or the fastening structure. The fastening state of the fastening structure is determined using the vibration data collected. The method and system enable detection of the fastening state of a fastening structure with low-power consumption and low cost.

An ultrasonic probe (100) includes an oscillator accommodating part (110), a first coil spring (130), and a collar (140). The oscillator accommodating part (110) has an accommodation shaft (116) having an ultrasonic oscillator (111a) accommodated therein, and a curved surface part (114) connected to one end portion of the accommodation shaft (116) and having formed thereon a curved surface (114a) facing a direction opposite to a direction in which the accommodation shaft (116) is present. The first coil spring (130) receives the curved surface (114a) of the curved surface part (114), and produces an elastic force pressing the curved surface (114a). The collar (140) accommodates the first coil spring (130) and the curved surface part (114), and restrains movement of the curved surface part (114) pressed by the first coil spring (130). The curved surface part (114) and the first coil spring (130) configure a spherical joint (100J).

Provided is a method for setting bottom-touching-determination standard capable of setting a bottom-touching-determination standard based on parameters with high reliability. The method for setting bottom-touching-determination standard includes a screwing step of screwing a measurement screw (11) into a measurement screw hole (13a), a parameter acquisition step of acquiring parameters in the screwing step, a bottom-touching-determination step of determining the presence or absence of bottom-touching on the basis of an axial force of the measurement screw, and a determination standard setting step of collating the determination result in the bottom-touching-determination step and the parameters to set the bottom-touching-determination standard.