Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this paper formulates a plane strain elastic–plastic model of a plate subject to shearing action by opposing rigid platens. Shear failure at the local level is modeled by a cohesive ...

We use a modified filament stretching rheometer to quantify the influence of a known controlled pre-shear history on the transient extensional viscosity of a dilute polymer solution. Two different types of pre-deformation are explored; both influence the subsequent stretching significantly, albeit in opposite ways. Small-amplitude oscillatory straining parallel to the direction of stretching en...

The purpose of this paper is to analysis the viscoelastic models under dynamic loading. A five-parameter model is chosen for study exhibits elastic, viscous, and retarded elastic response to shearing stress. The viscoelastic specimen is chosen which closely approximates the actual behavior of a polymer. The module of elasticity and viscosity coefficients are assumed to be space dependent i.e. f...

We have studied the syn-kinematic very low-grade metamorphism in a polyphase Variscan deformed region using X-ray diffraction techniques. Two phases of regional metamorphism are related to their respective episodes of penetrative deformation in the southern Central Iberian Zone. The data obtained suggest that the rocks did not reach metamorphic equilibrium, but strain favoured the progress of m...

The paper deals with the design of cognitive artefacts. It is supported that both normative and descriptive design approaches fail to acknowledge the co-adaptation between users and artefacts; this leads to the so-called design paradox and obstructs the co-evolution of practice and artefacts. In the first section, the paper discusses the task-artefact cycle and presents examples showing that th...

Physics|Solid State) STRESS FLUCTUATIONS IN CONTINUOUSLY SHEARED GRANULAR MEDIA by Brian J. Miller Department of Physics Duke University

The impact deformation and fracture behaviour of cobalt-based Haynes 188 superalloy are investigated by means of a split Hopkinson pressure bar. Impact tests are performed at strain rates ranging from 1×103 s-1 to 5×103 s-1 and temperatures between 25°C and 800°C. The experimental results indicate that the flow response and fracture characteristics of cobalt-based Haynes 188 superalloy are sign...

The temporal evolution of surface strain, resulting from a combination of normal and tangential loading forces on the fingerpad, was calculated from high-resolution images. A customized robotic device loaded the fingertip with varying normal force, tangential direction and tangential speed. We observed strain waves that propagated from the periphery to the centre of the contact area. Consequent...

in the present study, shearing properties of sugar cane stems were determined at five moisture content levels (46, 54, 62, 70 and 78% wb), three shearing speed (5, 10 and 15 mm min-1) and at ten positions on the stem. for measuring the shearing forces, the stems were severed by using a computer aided cutting apparatus. decrease in moisture content of stem from 78 to 46% wb led to 16.3 and 16.7%...