We consider current-current deformations that generalize T ¯ T ones, and show that they may be also introduced for integrable spin chains. In analogy with the integrable QFT setup, we define the ...deformation as a modification of the S matrix in the Bethe equations. Using results by Bargheer, Beisert and Loebbert we show that the deforming operator is composite and constructed out of two currents on the lattice; its expectation value factorizes like for T ¯ T . Such a deformation may be considered for any combination of charges that preserve the model's integrable structure.
The article describes the possibility of usage of drawing method for production of pipes of fibered composite AL-B. The authors suggest using a construction of drawing mill, where the material volume ...reduction is carried out on the floating plug. With an aim of quality improvement technological shell is used. There were examined the mechanisms of joint deforming of compact blank part and solid shell.
One strategy for reducing the sign problem in finite-density field theories is to deform the path integral contour from real to complex fields. If the deformed manifold is the appropriate combination ...of Lefschetz thimbles-or somewhat close to them-the sign problem is alleviated. Gauge theories require generalizing the definition of thimble decompositions, and therefore it is unclear how to carry out a generalized thimble method. In this paper we discuss some of the conceptual issues involved by applying this method to QED1+1 at finite density, showing that the generalized thimble method yields correct results with less computational effort than standard methods.
In this paper, deformation behaviors and microstructure evolution of a hot-rolled AZ31B magnesium alloy under cyclic loadings are investigated. The relationship between plastic deformation and ...microstructure evolution and the crack formation mechanisms are discussed. Under a high cyclic stress (90–140 MPa), steady ratcheting effect occurred in the material and the development of ratcheting strain went through three stages: 1) Stage I - initial rapid increase stage; 2) Stage II - steady stage; and 3) Stage III - final abrupt increase stage. Under a low cyclic stress (≤ 90 MPa), inconspicuous ratcheting effect was found in the material, indicating a light damage in the material. When the cyclic stress is below 30 MPa, no ratcheting effect is found and only elastic deformation occurs in the material. The formation of cracks in Stages I & II is mainly due to the activation of the basal slip system. The mean geometrically necessary dislocations (GND) are calculated to analyze the relationship between the basal slip and the ratcheting effect during the cyclic loading. Finally, a new approach is proposed to estimate the AZ31B magnesium alloy’s cyclic strength (at 107 cycles) according to the cyclic stress at which steady ratcheting effect starts to occur in the material.
A century ago, a Scottish biologist published ideas that would be built on generations later by those working in the field of statistical shape analysis. Kanti V. Mardia, Fred L. Bookstein, Balvinder ...S. Khambay and John T. Kent celebrate D'Arcy Thompson's most famous work on the 70th anniversary of his death
A century ago, a Scottish biologist published ideas that would be built on generations later by those working in the field of statistical shape analysis. Kanti V. Mardia, Fred L. Bookstein, Balvinder S. Khambay and John T. Kent celebrate D'Arcy Thompson's most famous work on the 70th anniversary of his death.
In analysing metal forming processes the deformation mechanism map (elastic-plastic, elastic-viscoplastic, or creep type behaviour) for a particular process is commonly built solely in relation to ...temperature; which can be acceptable for a defined modest strain rate range. However, for a given temperature, if strain rate variation is large, the deformation mechanism could vary significantly. In this paper, a deformation mechanism map is proposed to clarify the interacting effect of deformation conditions (temperature and strain rate) on workpiece behaviour in metal forming processes. Rate type deformation equations which can be used to comprehensively model the effect of temperature and strain rate on deformation mechanism characteristics are elucidated and as examples, determined for Ti–6Al–4V and Al–Mg alloy.
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•A deformation mechanism map is built incorporating the interacting effect of temperature and strain rate.•The map accurately clarifies the effect of deformation conditions on metal behaviour in a wide range of forming processes.•Rate type equations capture the smooth transition between different deformation mechanisms throughout forming processes.
In situ tensile tests, accompanied by scanning electron microscopy coupled with electron backscatter diffraction (EBSD) analyses were performed on neutron-irradiated 304L steel specimens (5.9 dpa, ...irradiation in boiling water reactor at 288 °C). Selected regions of interest were analyzed following tensile deformation of the specimens to increasing levels of strain, allowing for tracking and investigating strain-induced misorientation evolution, lattice rotation, twinning, and phase instability. Deformation-induced changes in EBSD misorientation parameters, such as kernel average misorientation (KAM) and grain reference orientation deviation (GROD), were analyzed as a function of the strain level (ε). The mapping of GROD values revealed the formation of specific “hot spots” (areas with high local misorientation) in the early stages of tensile deformation (ε ∼0–0.02) with values increasing much more quickly for irradiated specimens than for nonirradiated specimens. In contrast, average KAM values showed very little change in the small strain range (ε < 0.02) and fast growth at larger strain values.
Bulk nanostructured (ns)/ultrafine-grained (UFG) metallic materials possess very high strength, making them attractive for high strength, lightweight and energy efficient applications. The most ...effective approach to produce bulk ns/UFG metallic materials is severe plastic deformation (SPD). In the last 30 years, significant research efforts have been made to explore SPD processing of materials, SPD-induced microstructural evolutions, and the resulting mechanical properties. There have been a few comprehensive reviews focusing mainly on SPD processing and the mechanical properties of the resulting materials. Yet no such a review on SPD-induced microstructural evolutions is available. This paper aims to provide a comprehensive review on important microstructural evolutions and major microstructural features induced by SPD processing in single-phase metallic materials with face-centered cubic structures, body-centered cubic structures, and hexagonal close-packed structures, as well as in multi-phase alloys. The corresponding deformation mechanisms and structural evolutions during SPD processing are discussed, including dislocation slip, deformation twinning, phase transformation, grain refinement, grain growth, and the evolution of dislocation density. A brief review on the mechanical properties of SPD-processed materials is also provided to correlate the structure with mechanical properties of SPD-processed materials, which is important for guiding structural design for optimum mechanical properties of materials.
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