Dynamic modulus of urethane

Includes bibliographical references (leaf [91])Estimation of the properties of viscoelastic materials plays an important role in determining the behavior of the structures using them. To analyze the vibrational behavior of a structure bonded with viscoelastic material, estimation of its dynamic properties such as the complex modulus are critical. The objective of this thesis is to estimate the dynamic modulus of urethane using a non-resonant method (tripod test). In the tripod test method, cast cylindrical samples of urethane are strain gauged, and -- using a dual-channel FFT analyzer dynamic properties are measured as a function of frequency. A random mode of vibrations is used to excite the samples. Strain gauges estimate the dynamic strain applied on to the specimen. Four specimens of different sizes are tested. Strain gauging also aids in determining the pre-load applied onto the specimens.M.S. (Master of Science