A battery module containing a plurality of battery cells electrically connected to one another in series or in parallel, two contact surfaces (14a, 14b) for the purposes of tapping off a module voltage of the battery module (10) and at least one bolted joint device (22) for the purposes of fixing a component (12), in particular a current-conducting component, of the battery module (10), wherein the at least one bolted joint device (22) is provided with a sensor (26) for the purposes of determining a preload force applied to the bolted joint device (22).

A bolt axial force measurement apparatus of the present invention includes an echo detection section and an axial force calculation section. The echo detection section sets a head echo gate for the head echo and sets a bottom echo gate for the bottom echo, and executes tracking for a plurality of ultrasonic pulses emitted during tightening of the bolt so that the head echo gate and bottom echo gate are shifted independently to include the predetermined positions at the same position in the head echo gate and bottom echo gate.

In the present disclosure, embodiments including a system, probe and method 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 and shear wave reflections.

The systems and methods described herein are for monitoring the tightness of bolts. The systems and methods may be used with a mechanism to apply a percussive tap and with a recording or monitoring device for detecting and recording the acoustic signals that are generated by the percussive tap. The acoustic signals generated by percussive taps applied to bolts in various looseness states are analyzed and a machine learning model is developed that allows for determining bolt looseness based on the acoustic signals.

A portable inspecting device includes PZT transducers and performs active sensing to measure the characteristics of bolted connections. The PZT transducers are mounted on opposing ends of spring-loaded rods and can be moved apart to accommodate a structure for testing. The springs cause the PZT transducers to push against opposing parts of the structure in a stable but temporary fashion. The device can be physically moved to inspect the status and health of multiple different bolted connections.

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.

In the present disclosure, embodiments including a system, probe and method 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 and shear wave reflections.

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 battery module containing a plurality of battery cells electrically connected to one another in series or in parallel, two contact surfaces (14a, 14b) for the purposes of tapping off a module voltage of the battery module (10) and at least one bolted joint device (22) for the purposes of fixing a component (12), in particular a current-conducting component, of the battery module (10), wherein the at least one bolted joint device (22) is provided with a sensor (26) for the purposes of determining a preload force applied to the bolted joint device (22).

A method for measuring a preload of a fastener is described. The method, which may be practiced at least in part by an apparatus, includes establishing an initial value associated with an absence of the preload of the fastener and providing an adapter and a transducer rotatably coupled to the adapter. The transducer may be positioned in contact with the fastener. The transducer is caused to direct an incident ultrasonic wave to the fastener and to receive a reflected ultrasonic wave from the fastener. Data associated with the incident ultrasonic wave and the reflected sonic wave is used to generate a modified value associated with the preload of the fastener, and the preload of the fastener is calculated based on a difference between the initial value and the modified value.