The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Eric Paroissien - One of the best experts on this subject based on the ideXlab platform.
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Simplified stress analysis of multilayered Bonded Structure under 1D-bar kinematics
Composite Structures, 2020Co-Authors: Vincent Torrelli, Eric ParoissienAbstract:Many current materials and structural systems are layered. The structural performances of these multilayered systems are dependent on interfaces, the presence of which is inherent to them. A methodology for the simplified stress analysis of such Structures under 1D-bar kinematics is presented. The macro-element technique is used to solve the set of ordinary differential equations involved. A dedicated macro-element is formulated through the approximation of displacements fields by Taylor expansion power series. The predictions of the simplified stress analysis are in close agreements with those obtained by FE analyses. Finally, the influence of adhesive thickness and of the overlap length on the adhesive stress peaks is presented.
Vincent Torrelli - One of the best experts on this subject based on the ideXlab platform.
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Simplified stress analysis of multilayered Bonded Structure under 1D-bar kinematics
Composite Structures, 2020Co-Authors: Vincent Torrelli, Eric ParoissienAbstract:Many current materials and structural systems are layered. The structural performances of these multilayered systems are dependent on interfaces, the presence of which is inherent to them. A methodology for the simplified stress analysis of such Structures under 1D-bar kinematics is presented. The macro-element technique is used to solve the set of ordinary differential equations involved. A dedicated macro-element is formulated through the approximation of displacements fields by Taylor expansion power series. The predictions of the simplified stress analysis are in close agreements with those obtained by FE analyses. Finally, the influence of adhesive thickness and of the overlap length on the adhesive stress peaks is presented.
Uzi Landman - One of the best experts on this subject based on the ideXlab platform.
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hydrogen Bonded Structure and mechanical chiral response of a silver nanoparticle superlattice
Nature Materials, 2014Co-Authors: Bokwon Yoon, W D Luedtke, R N Barnett, Jianping Gao, Anil Desireddy, Brian E Conn, Terry P Bigioni, Uzi LandmanAbstract:Self-assembled nanoparticle superlattices, which consist of inorganic cores capped by organic ligands, can show emergent behaviour as a result of the coupling between their nanoscale components. The atom-level Structure of a silver nanoparticle superlattice, deduced from X-ray imaging and simulations, is now reported as well as its response to hydrostatic compression, which involves anomalous pressure softening and correlated chiral rotation of the nanoparticles.
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hydrogen Bonded Structure and mechanical chiral response of a silver nanoparticle superlattice
Nature Materials, 2014Co-Authors: Bokwon Yoon, W D Luedtke, R N Barnett, Jianping Gao, Anil Desireddy, Brian E Conn, Terry P Bigioni, Uzi LandmanAbstract:Self-assembled nanoparticle superlattices-materials made of inorganic cores capped by organic ligands, of varied Structures, and held together by diverse binding motifs-exhibit size-dependent properties as well as tunable collective behaviour arising from couplings between their nanoscale constituents. Here, we report the single-crystal X-ray Structure of a superlattice made in the high-yield synthesis of Na(4)Ag(44)(p-MBA)(30) nanoparticles, and find with large-scale quantum-mechanical simulations that its atomically precise Structure and cohesion derive from hydrogen bonds between bundledp-MBA ligands. We also find that the superlattice's mechanical response to hydrostatic compression is characterized by a molecular-solid-like bulk modulus B(0) = 16.7 GPa, exhibiting anomalous pressure softening and a compression-induced transition to a soft-solid phase. Such a transition involves ligand flexure, which causes gear-like correlated chiral rotation of the nanoparticles. The interplay of compositional diversity, spatial packing efficiency, hydrogen-bond connectivity, and cooperative response in this system exemplifies the melding of the seemingly contrasting paradigms of emergent behaviour 'small is different' and 'more is different'.
M Saito - One of the best experts on this subject based on the ideXlab platform.
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Stress analysis around DSCu/SS316 HIP Bonded interface
2001Co-Authors: S. Kikuchi, Y Nomura, M SaitoAbstract:Abstract HIP Bonded Structure of DSCu/SS316 is proposed for ITER plasma facing components. In 20th SOFT, we reported the fracture strength of HIP Bonded interface at ambient temperature. But first wall is at high temperature in operation, we estimate in this study the fracture strength of HIP Bonded interface at 473K as a first step of high temperature. The results of fracture strength test indicate that the fracture strength of HIP Bonded interface at high temperature is lower than that at ambient temperature. The fracture surfaces of specimens ruptured at ambient temperature and at 473K were observed. Crack surfaces were nearly 10 μm apart from the Bonded interface into DSCu side. Scanning electron microscope observation is considered to show the existence of the thin new layer in DSCu region in which the dispersed Al2O3 was diminished. Assuming the thin layer to be composed of Cu, fracture behavior of HIP Bonded Structure is simulated by three layers model DSCu/Cu/SS316 and the fracture strength is estimated by the stress intensity factor K. The analytical results conclude that crack propagates in DSCu/Cu interface more easily, which is good agreement with fracture surface in experiments.
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Stress analysis around DSCu/SS316 HIP Bonded interface
2001Co-Authors: S. Kikuchi, Y Nomura, M SaitoAbstract:Abstract HIP Bonded Structure of DSCu/SS316 is proposed for ITER plasma facing components. In 20th SOFT, we reported the fracture strength of HIP Bonded interface at ambient temperature. But first wall is at high temperature in operation, we estimate in this study the fracture strength of HIP Bonded interface at 473K as a first step of high temperature. The results of fracture strength test indicate that the fracture strength of HIP Bonded interface at high temperature is lower than that at ambient temperature. The fracture surfaces of specimens ruptured at ambient temperature and at 473K were observed. Crack surfaces were nearly 10 μm apart from the Bonded interface into DSCu side. Scanning electron microscope observation is considered to show the existence of the thin new layer in DSCu region in which the dispersed Al2O3 was diminished. Assuming the thin layer to be composed of Cu, fracture behavior of HIP Bonded Structure is simulated by three layers model DSCu/Cu/SS316 and the fracture strength is estimated by the stress intensity factor K. The analytical results conclude that crack propagates in DSCu/Cu interface more easily, which is good agreement with fracture surface in experiments.
Emily B Moore - One of the best experts on this subject based on the ideXlab platform.
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water modeled as an intermediate element between carbon and silicon
Journal of Physical Chemistry B, 2009Co-Authors: Valeria Molinero, Emily B MooreAbstract:Water and silicon are chemically dissimilar substances with common physical properties. Their liquids display a temperature of maximum density, increased diffusivity on compression, and they form tetrahedral crystals and tetrahedral amorphous phases. The common feature to water, silicon, and carbon is the formation of tetrahedrally coordinated units. We exploit these similarities to develop a coarse-grained model of water (mW) that is essentially an atom with tetrahedrality intermediate between carbon and silicon. mW mimics the hydrogen-Bonded Structure of water through the introduction of a nonbond angular dependent term that encourages tetrahedral configurations. The model departs from the prevailing paradigm in water modeling: the use of long-ranged forces (electrostatics) to produce short-ranged (hydrogen-Bonded) Structure. mW has only short-range interactions yet it reproduces the energetics, density and Structure of liquid water, and its anomalies and phase transitions with comparable or better accu...
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water modeled as an intermediate element between carbon and silicon
arXiv: Soft Condensed Matter, 2008Co-Authors: Valeria Molinero, Emily B MooreAbstract:Water and silicon are chemically dissimilar substances with common physical properties. Their liquids display a temperature of maximum density, increased diffusivity on compression, they form tetrahedral crystals and tetrahedral amorphous phases. The common feature to water, silicon and carbon is the formation of tetrahedrally coordinated units. We exploit these similarities to develop a coarse-grained model of water (mW) that is essentially an atom with tetrahedrality intermediate between carbon and silicon. mW mimics the hydrogen-Bonded Structure of water through the introduction of a nonbond angular dependent term that encourages tetrahedral configurations. The model departs from the prevailing paradigm in water modeling: the use of long-ranged forces (electrostatics) to produce short-ranged (hydrogen-Bonded) Structure. mW has only short-range interactions yet it reproduces the energetics, density and Structure of liquid water, its anomalies and phase transitions with comparable or better accuracy than the most popular atomistic models of water, at less than 1% of the computational cost. We conclude that it is not the nature of the interactions but the connectivity of the molecules that determines the structural and thermodynamic behavior of water. The speedup in computing time provided by mW makes it particularly useful for the study of slow processes in deeply supercooled water, the mechanism of ice nucleation, wetting-drying transitions, and as a realistic water model for coarse-grained simulations of biomolecules and complex materials.