Shimizu Construction Co., Ltd.

Mitsugu Kuramochi

Minoru Imai

Yoshitaka Yabe

Increasing use of thermo-mechanically treated high strength steels in construction projects has created a need for on-site inspection of welded joints by ultrasonic techniques. However, such steels are acoustically anisotropic, and corrections of test results for anisotropy, according to the traditional methodologies, require lengthy and complex preparation steps which are unsuitable for on-site testing. The present invention presents an automated quick and simple methodology, and a compact apparatus for determining the acoustic anisotropy in such materials. The apparatus is expected to lead to effective management of quality assurance not only in civil and architectural engineering projects but in heavy machinery and ship building industries.

Method for evaluation of acoustic anisotropy and measuring apparatus

A high-damping probe capable of obtaining not only sound velocity information but also other ultrasonic information useful for ultrasonic testing, such as the frequency and amplitude of the received wave, and also capable of increasing the accuracy of ultrasonic testing of structures made of concrete or other materials. The high-damping probe includes a transducer having a low-frequency damper attached thereto. By virtue of the above-described arrangement, the transmission wave will not oscillate for a long period of time and it is therefore possible to clearly discriminate between the transmission wave and the received wave. Since the received wave can be distinctly separated from the transmission wave, it is possible to obtain ultrasonic information such as the frequency and amplitude of the received wave. Further, it is possible to impart wide-band frequency characteristics to the probe, so that it becomes conformable to an ultrasonic testing device wherein the transmission frequencyt is variable. In addition, an ultrasonic measuring apparatus using the high-damping probe enables highly accurate measurement of the sound velocity of the shear wave, the thickness of the object and the position of an internal void.

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Tokyo, Japan

Mitsugu Kuramochi