title: Characterizing the low strain complex modulus of asphalt concrete specimens through optimization of frequency response functions.
abstract: 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.
authors.affiliation: Highway and Railway Engineering, KTH Royal Institute of Technology, Brinellvägen 23, 100 44 Stockholm, Sweden. andgud@kth.se
authors.forename: Anders
authors.initials: A
authors.lastname: Gudmarsson
authors.forename: Nils
authors.initials: N
authors.lastname: Ryden
authors.forename: Björn
authors.initials: B
authors.lastname: Birgisson
mesh_terms: D061725:Accelerometry; D000162:Acoustics; D003198:Computer Simulation; D003252:Construction Materials; D004548:Elasticity; D020342:Finite Element Analysis; D005583:Fourier Analysis; D006838:Hydrocarbons; D016014:Linear Models; D008422:Materials Testing; D008962:Models, Theoretical; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014783:Viscosity
chemical_list: D006838:Hydrocarbons; C006647:asphalt