RUI: Modal Testing Using Ultrasound Stimulated Radiation Force Excitation

Gustavus Adolphus College, Saint Peter MN

Investigators

Abstract

RUI: Modal Testing Using Ultrasound Stimulated Radiation Force Excitation Abstract: The goal of this faculty-student project is to investigate the capabilities of ultrasound stimulated radiation force excitation in air as a noncontact method of measuring vibrational modes. The unique characteristic of this method is that a driving force can be applied to the object through the interference of ultrasound signals, with no physical contact between the transducer and object. When ultrasound radiation force excitation is coupled with detection using a laser vibrometer, this provides the distinct advantage of both excitation and detection completely without contact. Since there is no mechanical contact required to vibrate the object, this technique has great potential in modal testing, especially in the study of Micro Electro-Mechanical Systems (MEMS) and similar small devices. Using the ultrasound radiation force, it is also possible to selectively excite different vibrational modes of an object while suppressing others. This project will result in a more fundamental understanding of the capabilities and limitations of the ultrasound radiation force, and its application for modal testing. In parallel to the detailed experimental studies, another major objective will be to create a computer model of this excitation process. This model will be essential for detailed quantitative studies of the response of some objects, to develop new techniques, and to study practical applications of the ultrasound radiation force excitation.