Roush Anatrol, 935 Benecia Ave., Sunnyvale, CA 94086
Although the vibrating beam technique has been widely used and demonstrated to be an effective technique for measuring the dynamic properties of materials, it has its own limitations. This is because the present analysis uses the fourth-order beam equations which do not adequately handle the boundary conditions of the test specimens especially for the fundamental mode of vibration. Because of that, measurements on the first and sometimes the second modes of vibration have been omitted which limits the frequency range where measurements could be made. To overcome such limitations, a new approach using finite element analysis has been developed to compute the dynamic properties of materials for several modes of vibration, including the lower ones. This analysis is suited for either extensional or shear deformation, depending on the geometry of the specimen. Results of using this analysis to compute the dynamic properties of the various proposed materials for the S2WG79 standard will be presented and discussed.