Download Free PDF. Download Free PDF. Strain localisation and grain breakage in sand under shearing at high mean stress:insights from in situ X-ray tomography. Acta Geotechnica, 2014. Cino Viggiani. Download PDF. Download Full PDF Package. This paper. A short summary of this paper. (PDF) Synchrotron X-ray Tomographic Quantification of Download Free PDF. Download Free PDF However, these prior studies did not link material behaviour to the detailed kinetics occurring at the microstructural scale during deformation, in which there is a complex interaction of evolving solid and liquid in a solidifying alloy. After only 90 µm of indentation, the highly localised strain
strain in the oxide layer. Typically, the maximum total strain was ~1.6 %. The choice of magnification for SEM imaging during testing was determined by the speckle size once the sample was mounted and placed in the SEM chamber. Fig.1a shows an image of the gold pattern, formed on samples polished prior to oxidation, at high magnification. Initiation of localized shear bands in plane strain Apr 01, 1980 · In plane-strain compression tests, shear bands were first detected at a strain of EI 0-036. This strain and a prior strain at which they were not detected are marked in Fig. 2. Also shown in Fig. 2 are the values of the tangent modulus % 458 MPa and the secant modulus , 59-05 GPa at the strain at which the shear bands were first observed. Localization of plastic strain at the microstructurlal however, that localised plasticity is a precursor and necessary condition for the nucleation of cracks.27 ,28 3336 Full-eld strain measurements depicting the development of plastic strain within individual grains in a polycrystalline material subjected to fatigue loading can
evolve from microdeformation processes in localised regions about 30 nm in diameter. As the deformation region develops, further localised deformation is induced. The growth and coalescence of such deformed nuclei create a narrow plastic zone. In the presence of dilatational stress, voids develop. This voided structure is Pinch and swell structures:evidence for strain either the strain hardening or weakening regime (for a de-tailed discussion of the theory see Rudnicki and Rice, 1975). However, strain localisation combined with material soften-ing is commonly seen in eld examples. A number of differ-ent processes have been shown theoretically to cause strain REINFORCED CONCRETE WALL BOUNDARY ELEMENT compression loads, with higher strain demands comparatively to the web. Therefore, care must be taken in BE detailing, so that under the compression phase of the cycle they can behave in a ductile manner (i.e., withstand large strains prior to failure). Figure 1:Plan view of a reinforced concrete wall, indicating web and BE locations
Dec 21, 2014 · This work presents results from a series of triaxial compression tests on two quartz sands (differing principally in grain shape), at confining pressures high enough to cause grain breakage during shearing. Tests are performed inside an X-ray scanner, which allows specimens to be imaged non-destructively as they deform. Observation of the acquired images clearly shows different mechanisms Temperature-independent Bragg grat ing based sensor Temperature-independent Bragg grat ing based sensor for monitoring regions of localised strain concentration Claire E Davis* a, Will G.A. Brown a, Paul R Stoddart b a Air Vehicles Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, VIC 3207 Australia. The underlying micromechanism remains to be clarified (the slope of the strain versus time curve) increases from zero to the dynamic level. The strain rate reaches 500 s-1. at the stress ~2000around tinues MPa, and con increasing to approximately 25001 prior to the fracture (Fig. 1(a)). Fig. 1(b) - s compares the typical stressstrain response of silicon carbide at the quasi-static and
The main purpose of this paper is a broad review of developments in observation and interpretation of localization in geomaterials in the laboratory, with an emphasis on low mean stress situations.