We determine the linear viscoelastic response of jammed packings of athermal repulsive viscous spheres, a model for emulsions, wet foams, and soft colloidal suspensions. We numerically measure the complex shear modulus, a fundamental characterization of the response, and demonstrate that low frequency response displays dynamic critical scaling near unjamming. Viscoelastic shear response is gove...

Poisson’s ratio in viscoelastic solids is in general a time dependent (in the time domain) or a complex frequency dependent quantity (in the frequency domain). We show that the viscoelastic Poisson’s ratio has a different time dependence depending on the test modality chosen; interrelations are developed between Poisson’s ratios in creep and relaxation. The difference, for a moderate degree of ...

Determining the mechanical properties at micro- and nanometer length scales using nanoindentation or atomic force microscopy is important to many areas of science and engineering. Here we establish equations for obtaining storage and loss modulus from oscillatory indentations by performing a nonlinear analysis of conical and spherical indentation in elastic and viscoelastic solids. We show that...

The mathematics and mechanics of the Shallow Trench Isolation process are described. The diffusionreaction problem is posed in terms of fundamental mass balance laws. Finite strain kinematics is invoked to model the large expansion of SiO2, dielectrics are modelled as viscoelastic solids and annealing-induced density relaxation of SiO2 is incorporated as a historydependent process. A levelset f...

Experiments have shown that shear waves induced in brain tissue can develop into shock waves, thus providing a possible explanation of deep traumatic injuries. Here, we study the formation soft viscoelastic solids subject to an imposed velocity at their boundary. We consider plane shearing motion semi-infinite half-space, which corresponds spatially one-dimensional problem. Incompressible whose...

Abstract We show that the Persson-Brener theory of crack propagation in viscoelastic solids gives a fracture energy factor $$G/G_0 = 1+f$$ G / 0 = 1 + f which is ...

We investigated the mechanical properties of two abundant, cytoplasmic proteins from Acanthamoeba, profilin and actin, and found that while both profilin and nonfilamentous actin alone behaved as solids, mixtures of the two proteins were viscoelastic liquids. When allowed to equilibrate, profilin formed a viscoelastic solid with mechanical properties similar to filamentous and nonfilamentous ac...

In a recent work, Wyss [Phys. Rev. Lett. 98, 238303 (2007)] have noted a property of "soft solids" under oscillatory shear, the so-called strain-rate frequency superposition. We extend this study to the case of soft solids under large-amplitude oscillatory shear (LAOS). We show results from LAOS studies in a monodisperse hydrogel suspension, an aqueous gel, and a biopolymer suspension and show ...