The mechanical properties and plastic deformation mechanisms of metal nanowires have been studied intensely for many years. One of the important yet unresolved challenges in this field is to bridge the gap in properties and deformation mechanisms reported for slow strain rate experiments (∼10-2 s-1), and high strain rate molecular dynamics (MD) simulations (∼108 s-1) such that a complete unders...

THE FRACTURE of ductile solids has frequently been observed to result from the large growth and coalescence of microscopic voids, a process enhanced by the superposition of hydrostatic tensile stresses on a plastic deformation field. The ductile growth of voids is treated here as a problem in continuum plasticity. First, a variational principle is established to characterize the flow field in a...

We present a contribution on the risk of hydraulic fracturing in CO2 geological storage using an analytical model of hydraulic fracturing in weak formations. The work is based on a MohrCoulomb dislocation model that is extended to account for material with fracture toughness. The complete slip process that is distributed around the crack tip is replaced by superdislocations that are placed in t...

190 Abstract In this paper, a new analytical method for solving stable crack propagation problems in a ductile panel with a row of cracks, is presented. The main purpose of the present study is to estimate the maximum load carrying capacity of such panels accurately. The so called Elastic Plastic Finite Element Alternating Method (Pyo et al. (1994)) was extended to account for the propagating c...

Extruded unplasticised Poly(Vinyl Chloride) (uPVC) pipes are certified using pressurised pipe tests. During these tests the pipes are subjected to a certain temperature and internal pressure, while the time-to-failure, the time at which the internal pressure drops due to rupture or fracture, is measured. These tests are time consuming and are therefore costly. To circumvent these costs a model-...

Excellent exposures on wave-cut platforms display along the northeastern Taiwan coast a thick Oligocene succession that suffered low-grade metamorphism. The strata show anisotropic ductile-brittle deformation associated with the Late Cenozoic Taiwan mountain building event. Paleomagnetic analyses suggest probable contraction-induced remagnetization of remanent magnetization, taking place before...

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...

Densification of cuboidal micrometer-sized lithium fluoride particles as ductile ceramic by spark plasma sintering (SPS) was investigated. Specimens were fabricated at different pressures and temperature conditions, ranging from 2 to 100 MPa at 500 C and from 200 to 700 C under 100 MPa of applied pressure, respectively. Dense specimens of 99 % relative density were fabricated by heating to 500 ...

Bin Zhou, M. D. Thouless, and S. M. Ward Department of Mechanical Engineering Department of Material Science and Engineering University of Michigan Ann Arbor, MI, 48109 Scientific Research Laboratory Ford Motor Company Dearborn, MI, 48124 Abstract A methodology for determining the cohesive facture parameters associated with pull-out of spot welds is presented. Since failure of a spot weld by pu...

The posterior sucker of a leech represents a fascinating natural system that allows the leech to adhere to different terrains and substrates. However, the mechanism of adhesion and desorption has not yet to be elucidated. In order to better understand how the adhesion is performed, we analyzed the surface structure, adsorption movements, the muscles' distribution, physical characteristics, and ...