Research on Parametric Modeling Technology of Weaving in Micro-Architecture Manufacture

With the assistance of parametric technology, micro-architecture design based on weaving is easier to express and apply accurately. This paper analyzes the parametric modeling principle of weaving in micro-architecture design, and studies the parametric modeling technology of weaving motif micro-architecture with the example of micro-architecture shared station design. The conclusion shows that the core parameter model of micro-architecture with weaving motif includes parallel line weaving micro-architecture, gradual weaving micro-architecture and random weaving micro-architecture, each of which has its own corresponding micro-architecture function, and the parameterization technology has an obvious optimization effect on the micro-architecture's envelope shape and manufacturing. Based on this, the combination of micro-architecture and advanced modeling technology is preliminary discussed to promote the design of micro-architecture to be more efficient, ecological and innovative, to promote the upgrading of micro-building manufacturing engineering.

Beneficial use of hyperbaric process conditions for welding of aluminium and copper alloys

The joining of components with as few weld layers as possible is an important aspect of weld seam design due to the resulting reduced manufacturing effort and reduced influence of thermal cycles on the base material as well as reduced distortion. For materials with good thermal conductivity, this is not easily possible. The energy density of the arc has been found to be the core parameter for determining the penetration. In the present work, it is shown how the use of a hyperbaric process environment (2 to 16 bar) allows an increase of the energy density of the arc and thus an increase of the penetration depth for selected aluminium and copper alloys. Furthermore, the effects of this novel approach on weld metal metallurgy are presented. It is shown that the penetration depth can be doubled by increasing the ambient pressure. Furthermore, a statistical model for the prediction of the penetration depth depending on the welding parameters will be presented.

An Analytical Model of a New T-cored Coil Used for Eddy Current Nondestructive Evaluation

A model of an axisymmetric probe with a new T-core coil that can be used in eddy current testing is developed. The truncated region eigenfunction expansion (TREE) method is used to analyze the coil impedance problem of the T-core coil located above a multi-layer conductive material. First, the magnetic vector potential expressions of each region are formulated, then the coefficients of the magnetic vector potential are derived by using the boundary conditions, finally, the closed form expression of the coil impedance is obtained. The normalized impedance changes of the T-core coil caused by the presence or absence of the multi-layer conductor are calculated using Mathematica. The presented T-core coil is compared with I-core coil and air-core coil. The effects of the T-core parameter a2, relative permeability μf and the thickness of the top section on the change in the coil impedance are discussed respectively. The analytical calculation results are compared with the results of finite element method, and the two agree very well, which verifies the correctness of the proposed T-core coil model.

Lattice Nomenclature Survey from LGA to Modern LBM

Lattice configuration is a core parameter in Lattice-Boltzmann (LB) methods, both from theoretical and implementation standpoints. As LB methods have progressed over the past decades, a variety of lattice configurations have been proposed and referred to according to a plurality of lattice nomenclature systems that usually include the Euclidean space dimensionality, the lattice velocity count and, in fewer instances, the discretization order in their format. This work surveys lattice nomenclature systems, or lattice naming schemes, along the history of LB methods, starting from their Lattice Gas Automata (LGA) predecessor method, up to the present time. Findings include multiple lattice categories, competing naming standards, ambiguous names particularly in higher-order models, naming systems of varying model parameter scopes, and lack of unambiguous naming schemes even for space-filling, Bravais lattice types.

Raman Characterization on Two-Dimensional Materials-Based Thermoelectricity

The emergence and development of two-dimensional (2D) materials has provided a new direction for enhancing the thermoelectric (TE) performance due to their unique structural, physical and chemical properties. However, the TE performance measurement of 2D materials is a long-standing challenge owing to the experimental difficulties of precise control in samples and high demand in apparatus. Until now, there is no universal methodology for measuring the dimensionless TE figure of merit (ZT) (the core parameter for evaluating TE performance) of 2D materials systematically in experiments. Raman spectroscopy, with its rapid and nondestructive properties for probing samples, is undoubtedly a powerful tool for characterizing 2D materials as it is known as a spectroscopic ‘Swiss-Army Knife’. Raman spectroscopy can be employed to measure the thermal conductivity of 2D materials and expected to be a systematic method in evaluating TE performance, boosting the development of thermoelectricity. In this review, thermoelectricity, 2D materials, and Raman techniques, as well as thermal conductivity measurements of 2D materials by Raman spectroscopy are introduced. The prospects of obtaining ZT and testing the TE performance of 2D materials by Raman spectroscopy in the future are also discussed.