Experimental validation of a fractional model for creep/recovery testing of asphalt mixtures

Linear and Nonlinear Fractional Hereditary Constitutive Laws of Asphalt Mixtures

“…While the integer order derivative involves the knowledge of the state of the system at one or more previous instants, when the fractional operator appears the entire past history (hereditary materials) gives information at the given time instant (long tail memory). From recent literature on the subject for bitumen and asphalt mixture based upon fractional constitutive laws the readers may be referred to (Di Paola et al 2009;Celauro et al 2012;Stastna, Zanzotto 1994, 1996Oeser et al 2008). In previous papers the mechanical model was composed of a fractional element alone (usually termed as springpot in literature) or arranged in parallel with a spring.…”

Computational analysis of the creep behaviour of bituminous mixtures

“…A step forward in the constitutive modelling of asphalt concretes can be achieved, in terms of theoretical generalisation of the rheological models, by means of the continuum thermomechanics, introducing concepts as the Helmholtz free energy and the dissipative inequality of Clausius-Duhem [5][6][7][8]. Alternative approaches rely on the fractional models [9][10][11][12], the continuum damage mechanics [13,14] or the distinct element method [15][16][17][18]. This paper, after providing a brief summary of a thermodynamically congruent visco-elastic model, presents and discusses a plastic flow law that completes the constitutive modelling framework, on the basis of inviscid plasticity and isotropic hardening.…”

Young’s modulus and creep compliance of GaAs and Ga1-xMnxAs ferromagnetic thin films under thermal stress at varied manganese doping levels

“…This implies that the applied stress, in case of manganese dopant of 1 %, creates more space (free volume) for internal molecular motions (chain slippage) and the material becomes softer. For the range of MDL from 1 to 10 %, the manganese atoms occupy intermolecular spaces and reduce the space that would have been available for internal movements [20,[24][25][26]. This makes the material rigid.…”