An experiment for determination of the mechanical property in shear for a linear, isotropic viscoelastic solid

Measurement of the Isotropic Dynamic Young's Modulus in a Seismically Excited Cantilever Beam Using a Laser Sensor

“…The fact that the loss factor is very low also explains why some &&#uctuation'' is observed in the experimental curves: namely, the unavoidable measurement errors a!ect more the loss factors than the absolute values, the former being very small in value. 4. CONCLUSIONS This paper has presented an approach to the measurement of the dynamic Young's modulus for a viscoelastic material by using a contactless sensor, based on a laser emitter}receiver.…”

“…Gottenberg and Christensen [4] described an experimental technique to determine the complex shear modulus of a linear, isotropic, viscoelastic solid and its dependence on frequency and temperature.…”

Determination of the Viscoelastic Shear Modulus Using Forced Torsional Vibrations

“…If a mass with mass moment of inertia / and a torsional spring of constant k are attached to one end of the cylinder as shown in figure 1, and the other end of the cylinder is subjected to a harmonically varying torque, then the expression for the angular acceleration response ratio of the top plane of the cylinder to the bottom plane is given by [4,5] ^ Mrgp^/^ [C,a*sin(ft*)+cos(ft*)]-' (1) (7) Thus, if R and 4> are the measured ampHtude ratio and phase angle, respectively, and all the physical and geometric parameters of the specimen are determined by other means, then G' and G" can be found using eqs (6) and (7). However, because of the complexity of these equations, G' and G" cannot be solved for explicity.…”

“…In addition, the fixture itself must be free from structural resonances over a broad frequency range and for test samples of varying length and diameter. The design chosen was a combination of certain features of previous works [4,5] and is shown in figure 2. through a moment arm about the center of the spring of radius r^.…”

“…Some of these methods have been summarized [1,2]' and those that have been used more recently appear in a collection of abstracts [3]. The method described herein, which uses forced torsional vibrations, is an updated version of previous works [4,5]. It was selected because it most easily met the requirements placed on the geometry and dimensions of the sample, a circular cylinder whose diameter ranged from 2 to 9 cm and whose length ranged to 15 cm.…”