Characterizing the low strain complex modulus of asphalt concrete specimens through optimization of frequency response functions

• Published in: The Journal of the Acoustical Society of America Vol. 132; no. 4; p. 2304
• Main Authors: Gudmarsson, Anders, Ryden, Nils, Birgisson, Björn
• Format: Journal Article
• Language: English
• Published: United States 01.10.2012
• Subjects: Accelerometry; Acoustics; Computer Simulation; Construction Materials; Elasticity; Finite Element Analysis; Fourier Analysis; Hydrocarbons; Linear Models; Materials Testing; Models, Theoretical; Reproducibility of Results; Stress, Mechanical; Temperature; Time Factors; Viscosity
• ISSN: 1520-8524
• DOI: 10.1121/1.4747016

Measured and finite element simulated frequency response functions are used to characterize the low strain (~10(-7)) complex moduli of an asphalt concrete specimen. The frequency response functions of the specimen are measured at different temperatures by using an instrumented hammer to apply a load and an accelerometer to measure the dynamic response. Theoretical frequency response functions are determined by modeling the specimen as a three-dimensional (3D) linear isotropic viscoelastic material in a finite element program. The complex moduli are characterized by optimizing the theoretical frequency response functions against the measured ones. The method is shown to provide a good fit between the frequency response functions, giving an estimation of the complex modulus between minimum 500 Hz and maximum 18|000 Hz depending on the temperature. Furthermore, the optimization method is shown to give a good estimation of the complex modulus master curve.