Aditya Kumar

Georgia Institute of Technology | GT · School of Civil & Environmental Engineering

This Note lays out the specialization of the two-potential constitutive framework — also known as the “generalized standard materials” framework — to rubber viscoelasticity. Inter alia, it is shown that a number of popular rubber viscoelasticity formulations, introduced over the years following different approaches, are special cases of this framew...

A macroscopic theory is proposed to describe, explain, and predict the nucleation and propagation of fracture and healing in elastomers undergoing arbitrarily large quasistatic deformations. The theory, which can be viewed as a natural generalization of the phase-field approximation of the variational theory of brittle fracture of Francfort and Mar...

In a recent contribution, Kumar et al. (J Mech Phys Solids 112:523–551, 2018) have introduced a macroscopic theory aimed at describing, explaining, and predicting the nucleation and propagation of fracture and healing in elastomers undergoing arbitrarily large quasistatic deformations. The purpose of this paper is to present an alternative derivati...

In a recent contribution, Kumar et al. [23] have introduced a phase-field formulation and associated numerical implementation aimed at modeling the nucleation and propagation of fracture and healing in elastomers undergoing arbitrarily large quasistatic deformations, phenomena that have come into clear focus thanks to new experiments carried out at...

Twenty years in since their introduction, it is now plain that the regularized formulations dubbed as phase-field of the variational theory of brittle fracture of Francfort and Marigo (1998) provide a powerful macroscopic theory to describe and predict the propagation of cracks in linear elastic brittle materials under arbitrary quasistatic loading...

Frontal polymerization (FP) is a rapid, energy-efficient technique for the manufacturing of polymeric materials and composites. It has also emerged as a way to rapidly alter the shape of partially cured polymeric materials through mechanical deformation. The first objective of this paper is to introduce a coupled thermo-chemo-mechanical theory capa...

In a recent contribution, Kumar et al. (J Mech Phys Solids 142:104027, 2020) have introduced a comprehensive macroscopic phase-field theory for the nucleation and propagation of fracture in linear elastic brittle materials under arbitrary quasistatic loading conditions. The theory can be viewed as a natural generalization of the phase-field approxi...

In a recent contribution, Kumar, Bourdin, Francfort, and Lopez-Pamies (J. Mech. Phys. Solids 142:104027, 2020) have introduced a comprehensive macroscopic phase-field theory for the nucleation and propagation of fracture in linear elastic brittle materials under arbitrary quasistatic loading conditions. The theory can be viewed as a natural general...

Frontal polymerization, which involves a self-propagating polymerizing reaction front, has been considered as a rapid, energy-efficient, and environmentally friendly methodology to manufacture lightweight, high-performance thermoset polymers, and composites. Previous work has reported that the introduction of thermally conductive elements can enhan...

A numerical and analytical study is made of the macroscopic or homogenized viscoelastic response of suspensions of rigid inclusions in rubber under finite quasistatic deformations. The focus is on the prototypical case of random isotropic suspensions of equiaxed inclusions firmly embedded in an isotropic incompressible Gaussian rubber with constant...

This note presents approximate analytical expressions for the velocity of the self‐propagating reaction front in the frontal polymerization of thermoset polymers and composites. Prior estimates available in the literature for the front velocity have been limited by their applicability to simple reaction kinetics. The improved estimates provided in...

Despite being commonly credited with initiating the field of cavitation in elastomers, the famed poker-chip experiments of Gent and Lindley (1959) have yet to be fully explained. One likely reason for their elusiveness is that it had long been presumed that cavitation in elastomers was a phenomenon that could be explained solely on the basis of the...

Through direct comparisons with experiments, Lefèvre et al. (Int. J. Frac. 192:1–23, 2015) have recently confirmed the prevailing belief that the nonlinear elastic properties of rubber play a significant role in the so-called phenomenon of cavitation—that is, the sudden growth of inherent defects in rubber into large enclosed cavities/cracks in res...