Ice streams are fast flowing bands of ice separated from stagnant ridges by shear margins. The mechanisms controlling the location of the margins remain unclear. We use published ice deformation data and a simple one-dimensional thermal model to show that West Antarctic ice stream margins have temperate ice over a substantial fraction of their thickness, a condition that may control their width...

Shear-induced structural transitions of a micellar cubic phase during large amplitude oscillatory shear flow is studied with time-resolved oscillatory rheological small angle neutron scattering. This technique allows us to resolve the structural changes within a cycle of oscillation. By applying a strain rate near the critical melting shear rate, melting and recrystallization occurs in a cyclic...

Reported mechanical properties of orbital connective tissue and fat have been too sparse to model strain-stress relationships underlying biomechanical interactions in strabismus. We performed rheological tests to develop a multi-mode upper convected Maxwell (UCM) model of these tissues under shear loading. From 20 fresh bovine orbits, 30 samples of connective tissue were taken from rectus pulle...

The ideal strength of a material is the stress at which the lattice itself becomes unstable and, hence, sets a firm upper bound on the mechanical strength the material can have. The present paper includes an ab-initio calculation of the ideal shear strength of Fe. It is, to our knowledge, the first such computation for any ferromagnetic material. The paper also elaborates on our earlier calcula...

In recent work it was clarified that amorphous solids under strain control do not possess nonlinear elastic theory in the sense that the shear modulus exists but nonlinear moduli exhibit sample-to-sample fluctuations that grow without bound with the system size. More relevant, however, for experiments are the conditions of stress control. In the present Rapid Communication we show that also und...

Muscle fascicles insert into a sheet-like aponeurosis. Adjacent aponeuroses are structurally in contact with each other, and ultimately merge into a common tendon. Consequently, fascicle shortening in planes of tissue layers in adjacent compartments must cause sliding between aponeuroses parallel to the acting forces. In this study, we used velocity-encoded, phase-contrast, and water-saturated ...

We study the transient drag force FD on a localized intruder in a granular medium composed of spherical glass particles. A flat plate is translated horizontally from rest through the granular medium to observe how FD varies as a function of the medium's initial volume fraction, ϕ. The force response of the granular material differs above and below the granular critical state, ϕc, the volume fra...

The novelty of this study is presentation of an exact solution for prediction of postbuckling behavior of shear deformable micro- and nano-scale beams based on modified couple stress theory and using principle of minimum potential energy. Timoshenko and Reddy-Levinson beam theories are applied to consider the shear deformation effect and Von Karman nonlinear kinematics is used to describe the n...

BACKGROUND The role played by the thoracolumbar fascia in chronic low back pain (LBP) is poorly understood. The thoracolumbar fascia is composed of dense connective tissue layers separated by layers of loose connective tissue that normally allow the dense layers to glide past one another during trunk motion. The goal of this study was to quantify shear plane motion within the thoracolumbar fasc...

We use shear transformation zone (STZ) theory to develop a deformation map for amorphous solids as a function of the imposed shear rate and initial material preparation. The STZ formulation incorporates recent simulation results [T. K. Haxton and A. J. Liu, Phys. Rev. Lett. 99, 195701 (2007)] showing that the steady state effective temperature is rate dependent. The resulting model predicts a w...