National Research Council of Canada

Silvio E Kruger

Jean-Pierre Monchalin

Guy Lamouche

Zhigang Sun

Daniel Levesque

Kuo-Ting Wu

Daniel Lévesque

Methods and systems for determining a change in condition of a rock bolt. Some methods may comprise, at a first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a first time of flight for each of the shear and longitudinal waves, at a second point in time after the first point in time, propagating shear and longitudinal ultrasonic waves along the rock bolt to measure a second time of flight for each of the shear and longitudinal waves, and using the relative changes of the first and second time of flights, determining the change in condition of the rock bolt section.

Methods and systems for ultrasonic rock bolt condition monitoring

In an ultrasonic transducer assembly, a conformable ultrasonic transducer has a piezoelectric layer and electrodes able to conform to curved surfaces, and a clamp for pressing the transducer into ultrasonic contact with a curved surface. Conformability is ensured with a thin, porous piezoelectric layer and suitable electrical conductors and insulators. The ultrasonic transducer may operate without further thermal shielding under harsh environments and/or at high temperatures.

Ultrasonic transducer assembly and system for monitoring structural integrity

A method and system is disclosed for determining a property of an object by measuring ultrasonic attenuation. With the proposed method, a measured ultrasonic interaction signal of the object is compared with a reference signal produced using the same generation and detection setup, but using a reference part. The reference ultrasonic signal has low attenuation, and exhibits equivalent diffraction properties as the object, with respect to a broadband ultrasonic pulse. The difference is attributable to the attenuation of the object. The attenuation as a function of frequency, the attenuation spectrum, is fitted to a model to obtain a parameter useful for identifying one of the many properties of an object that varies with ultrasonic attenuation.

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Brossard, Canada

Silvio E Kruger