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Jun Liang - One of the best experts on this subject based on the ideXlab platform.

  • stiffness design of a multilayer arbitrary Bcc Lattice structure with face sheets
    Composite Structures, 2019
    Co-Authors: Yabo Liu, Zhichao Dong, Xiaohu Lin, Jun Liang
    Abstract:

    Abstract In this paper, a theoretical stiffness design approach for a body-centered cubic (Bcc) Lattice structure is proposed. Although numerous studies have focused on Lattice structures, particularly Bcc Lattice structure, there are still some issues that must be further investigated. Homogenization method is always followed that the mechanical properties of Lattice structure can be achieved by directly solving the unit cell, since the structure is a periodically repeated sequence of a unit cell. However, the equivalent modulus varies a lot with different array configurations from our study, which indicates that the spatial array configuration also has an important influence on the equivalent mechanical properties. In this paper, “large unit cell” assumption is used to characterize the equivalent modulus of the Lattice structure considering array configuration effect, and then validated using the finite element method (FEM) and experiment. The results demonstrate that the mechanical properties vary significantly for different array configurations, even those with the same unit cell topology. Furthermore, the proposed method is extended to an arbitrary Bcc unit cell to broaden its application for stiffness design of engineering parts. This research provides a guidance for the stiffness design of lightweight Lattice structures.

  • determination of the strength of a multilayer Bcc Lattice structure with face sheets
    International Journal of Mechanical Sciences, 2019
    Co-Authors: Yabo Liu, Zhichao Dong, Jun Liang
    Abstract:

    Abstract The body-centered cubic (Bcc) Lattice, as a type of cellular Lattice structure, has been widely researched with the representative volume element (RVE) homogenization method. This ideal theoretical approach requires infinite unit cells in a structure, which is unrealistic and unfeasible with the current manufacturing technology. In this paper, a new theoretical approach considering the effect of array configuration is developed to predict the strength of a multilayer Bcc Lattice structure. First, the compression behavior of the multilayer Bcc Lattice structure is analyzed by finite element method (FEM) simulation. Then, an analytical model inspired by the combination of the derived stress-strain curve and the specific contour is built. Predictions of the compression strength are compared with the FEM results for multilayer structures with various spatial array configurations to validate the applicability of the proposed model. And, they are in very good agreement within acceptable errors.

Timothy P Lodge - One of the best experts on this subject based on the ideXlab platform.

  • molecular exchange in ordered diblock copolymer micelles
    Macromolecules, 2011
    Co-Authors: Soohyung Choi, Frank S Bates, Timothy P Lodge
    Abstract:

    Molecular exchange kinetics of diblock copolymers forming spherical micelles packed on a body-centered cubic (Bcc) Lattice were investigated using time-resolved small-angle neutron scattering (TR-SANS). Ordered arrays of polystyrene spheres were prepared by mixing 15 vol % poly(styrene-b-ethylene-alt-propylene) (PS−PEP) in squalane, a highly selective solvent for the PEP block. Two pairs of diblock copolymers were examined, characterized by two different PS core block molecular weights (⟨MPS⟩ = 26500 and 42800). Each pair contained two nearly identical diblock copolymers, one with a deuterated PS block (dPS−PEP) and the other with a protonated PS block (hPS−PEP). Protonated and deuterated squalane were blended to achieve a contrast-matched condition with uniformly mixed dPS and hPS (50/50 by volume) core chains. Beginning with a statistically random array of pure dPS and hPS cores distributed on the Bcc Lattice, molecular exchange was monitored at multiple temperatures by TR-SANS. Exchange of deuterated a...

  • mechanisms and epitaxial relationships between close packed and Bcc Lattices in block copolymer solutions
    Journal of Physical Chemistry B, 2003
    Co-Authors: Joona Bang, Timothy P Lodge
    Abstract:

    The epitaxial relationships between two close-packed Lattices (face-centered cubic (fcc) and hexagonally close packed (hcp)) and the body-centered cubic (Bcc) Lattice of spherical micelles were investigated by small-angle X-ray scattering (SAXS) in two in situ shear cells. Two symmetric poly(styrene-b-isoprene) diblock copolymers with block molecular weights of 8.0 × 103 and 7.0 × 103 g/mol, and 1.5 × 104 and 1.5 × 104 g/mol, respectively, were employed. Thermoreversible fcc → Bcc order−order transitions were identified in three styrene-selective solvents, dimethyl phthalate, diethyl phthalate and dibutyl phthalate, and in two isoprene-selective solvents, tetradecane and squalane. Upon shearing an fcc solution, a mixture of highly oriented fcc and hcp crystals was produced, due to the random stacking of the {111} planes along the shear gradient. A Bcc phase was grown epitaxially from each hcp/fcc mixture by heating to a temperature within the Bcc window without shear. By employing two shear cells, access ...

Yabo Liu - One of the best experts on this subject based on the ideXlab platform.

  • stiffness design of a multilayer arbitrary Bcc Lattice structure with face sheets
    Composite Structures, 2019
    Co-Authors: Yabo Liu, Zhichao Dong, Xiaohu Lin, Jun Liang
    Abstract:

    Abstract In this paper, a theoretical stiffness design approach for a body-centered cubic (Bcc) Lattice structure is proposed. Although numerous studies have focused on Lattice structures, particularly Bcc Lattice structure, there are still some issues that must be further investigated. Homogenization method is always followed that the mechanical properties of Lattice structure can be achieved by directly solving the unit cell, since the structure is a periodically repeated sequence of a unit cell. However, the equivalent modulus varies a lot with different array configurations from our study, which indicates that the spatial array configuration also has an important influence on the equivalent mechanical properties. In this paper, “large unit cell” assumption is used to characterize the equivalent modulus of the Lattice structure considering array configuration effect, and then validated using the finite element method (FEM) and experiment. The results demonstrate that the mechanical properties vary significantly for different array configurations, even those with the same unit cell topology. Furthermore, the proposed method is extended to an arbitrary Bcc unit cell to broaden its application for stiffness design of engineering parts. This research provides a guidance for the stiffness design of lightweight Lattice structures.

  • determination of the strength of a multilayer Bcc Lattice structure with face sheets
    International Journal of Mechanical Sciences, 2019
    Co-Authors: Yabo Liu, Zhichao Dong, Jun Liang
    Abstract:

    Abstract The body-centered cubic (Bcc) Lattice, as a type of cellular Lattice structure, has been widely researched with the representative volume element (RVE) homogenization method. This ideal theoretical approach requires infinite unit cells in a structure, which is unrealistic and unfeasible with the current manufacturing technology. In this paper, a new theoretical approach considering the effect of array configuration is developed to predict the strength of a multilayer Bcc Lattice structure. First, the compression behavior of the multilayer Bcc Lattice structure is analyzed by finite element method (FEM) simulation. Then, an analytical model inspired by the combination of the derived stress-strain curve and the specific contour is built. Predictions of the compression strength are compared with the FEM results for multilayer structures with various spatial array configurations to validate the applicability of the proposed model. And, they are in very good agreement within acceptable errors.

Balazs Csebfalvi - One of the best experts on this subject based on the ideXlab platform.

  • An Evaluation of Prefiltered B-Spline Reconstruction for Quasi-Interpolation on the Body-Centered Cubic Lattice
    IEEE Transactions on Visualization and Computer Graphics, 2010
    Co-Authors: Balazs Csebfalvi
    Abstract:

    In this paper, we demonstrate that quasi-interpolation of orders two and four can be efficiently implemented on the Body-Centered Cubic (Bcc) Lattice by using tensor-product B-splines combined with appropriate discrete prefilters. Unlike the nonseparable box-spline reconstruction previously proposed for the Bcc Lattice, the prefiltered B-spline reconstruction can utilize the fast trilinear texture-fetching capability of the recent graphics cards. Therefore, it can be applied for rendering Bcc-sampled volumetric data interactively. Furthermore, we show that a separable B-spline filter can suppress the postaliasing effect much more isotropically than a nonseparable box-spline filter of the same approximation power. Although prefilters that make the B-splines interpolating on the Bcc Lattice do not exist, we demonstrate that quasi-interpolating prefiltered linear and cubic B-spline reconstructions can still provide similar or higher image quality than the interpolating linear box-spline and prefiltered quintic box-spline reconstructions, respectively.

  • dc splines revisiting the trilinear interpolation on the body centered cubic Lattice
    Vision Modeling and Visualization, 2010
    Co-Authors: Balazs Domonkos, Balazs Csebfalvi
    Abstract:

    In this paper, we thoroughly study a trilinear interpolation scheme previously proposed for the Body-Centered Cubic (Bcc) Lattice. We think that, up to now, this technique has not received the attention that it deserves. By a frequency-domain analysis we show that it can isotropically suppress those aliasing spectra that contribute most to the postaliasing effect. Furthermore, we present an efficient GPU implementation, which requires only six trilinear texture fetches per sample. Overall, we demonstrate that the trilinear interpolation on the Bcc Lattice is competitive to the linear box-spline interpolation in terms of both efficiency and image quality. As a generalization to higher-order reconstruction, we introduce DC-splines that are constructed by convolving a Discrete filter with a Continuous filter, and easy to adapt to the Face-Centered Cubic (FCC) Lattice as well.

  • pass band optimal reconstruction on the body centered cubic Lattice
    Vision Modeling and Visualization, 2008
    Co-Authors: Balazs Csebfalvi, Balazs Domonkos
    Abstract:

    In this paper, a pass-band optimal reconstruction technique is adapted to the Body-Centered Cubic (Bcc) Lattice. In order to perform the frequencydomain preprocessing, we derive a practical Discrete Fourier Transform (DFT) for Bcc-sampled data. In the discrete frequency domain our DFT provides a natural isotropic periodicity on a FaceCentered Cubic (FCC) pattern, unlike the previous method, which leads to periodicity on a sheared Cartesian pattern. One of the most important advantages of our approach is that no specialized FFT implementation is required, as basically the well-known traditional FFT libraries can be directly used for calculating the discrete frequency coefficients. Furthermore, the proposed DFT can be easily adapted to FCC-sampled data as well. We show that a prefiltered pass-band optimal reconstruction based on our DFT can capture the high-frequency details much better than the previously proposed generalized interpolation method.

J A Plascak - One of the best experts on this subject based on the ideXlab platform.

  • monte carlo study of the phase diagram of disordered fe p al 1 p alloys a site diluted isotropic heisenberg model
    Physical Review B, 2021
    Co-Authors: J B Santosfilho, J A Plascak, D P Landau
    Abstract:

    A site-diluted classical Heisenberg model on the Bcc Lattice, with only isotropic nearest-neighbor exchange interactions, is used to describe the phase diagram of ${\mathrm{Fe}}_{p}\ensuremath{-}{\mathrm{Al}}_{q}$ alloys ($p+q=1$) in the structurally disordered phase. Due to the larger size of Al atoms, the Fe-Fe exchange interactions along the border of the Al clusters are assumed to increase since the distance between Fe atoms becomes smaller in this region and remains constant for the rest of the Lattice. However, for higher Al concentrations the Fe-Fe exchange interaction should decrease as a result of the increase of the Lattice size parameter. Considering these assumptions, we have employed Monte Carlo simulations to obtain the thermodynamic properties of the model and obtain quite good fits to the experimental data of the transition temperature as a function of $q$. The results are still better than those recently obtained by assuming superexchange interactions induced by Al between next-nearest-neighbor Fe atoms.

  • monte carlo study of the change of critical temperature in a diluted ising model due to configuration disorder
    Physics Letters A, 2007
    Co-Authors: W R Aguirrecontreras, Ligia E Zamora, G Perez A Alcazar, J A Plascak, J Restrepo
    Abstract:

    Abstract Monte Carlo simulations on a diluted Ising Hamiltonian were used to obtain the susceptibility of virtual binary samples (conformed by ferromagnetic atoms and non-magnetic atoms) on a Bcc Lattice. Samples size of L = 10 were constructed with different configuration order using random mixtures. The susceptibility curves illustrate that the critical temperature decreases when the disorder in the samples increase. From fittings of the exchange interaction versus the concentration of non-magnetic atoms it was possible to reasonably describe the magnetic phase diagram of the Fe 1 − q Al q alloys.