A thermo-viscoelastic–viscoplastic–viscodamage constitutive model for asphaltic materials

• Published in: International journal of solids and structures Vol. 48; no. 1; pp. 191 - 207
• Main Authors: Darabi, Masoud K., Abu Al-Rub, Rashid K., Masad, Eyad A., Huang, Chien-Wei, Little, Dallas N.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2011; Elsevier
• Subjects: Applied sciences; Buildings. Public works; Continuum damage mechanics; Exact sciences and technology; Finite element implementation; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Nonlinear viscoelasticity; Physics; Road construction. Pavements. Maintenance; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Surfacing; Transportation infrastructure; Viscodamage; Viscoplasticity; Finite element implementation; Continuum damage mechanics; Viscodamage; Viscoplasticity; Nonlinear viscoelasticity; Constitutive equation; Viscoelasticity; Invariant; Nucleation; Thermoviscoelasticity; Temperature effect; Iterative method; Modeling; Finite element method; Asphalt; Inelasticity; Damaging; Strain rate; Thermomechanical properties; Experimental study; Cavitation; Radial return method; Recursive method; Thermoviscoplasticity; Non linear effect; Effective medium model
• ISSN: 0020-7683; 1879-2146
• DOI: 10.1016/j.ijsolstr.2010.09.019

A temperature-dependent viscodamage model is proposed and coupled to the temperature-dependent Schapery’s nonlinear viscoelasticity and the temperature-dependent Perzyna’s viscoplasticity constitutive model presented in Abu Al-Rub et al. (2009) and Huang et al. (in press) in order to model the nonlinear constitutive behavior of asphalt mixes. The thermo-viscodamage model is formulated to be a function of temperature, total effective strain, and the damage driving force which is expressed in terms of the stress invariants of the effective stress in the undamaged configuration. This expression for the damage force allows for the distinction between the influence of compression and extension loading conditions on damage nucleation and growth. A systematic procedure for obtaining the thermo-viscodamage model parameters using creep test data at different stress levels and different temperatures is presented. The recursive-iterative and radial return algorithms are used for the numerical implementation of the nonlinear viscoelasticity and viscoplasticity models, respectively, whereas the viscodamage model is implemented using the effective (undamaged) configuration concept. Numerical algorithms are implemented in the well-known finite element code Abaqus via the user material subroutine UMAT. The model is then calibrated and verified by comparing the model predictions with experimental data that include creep-recovery, creep, and uniaxial constant strain rate tests over a range of temperatures, stress levels, and strain rates. It is shown that the presented constitutive model is capable of predicting the nonlinear behavior of asphaltic mixes under different loading conditions.