Metal Wire Diameter Research Articles

Compression performance and low-frequency damping characteristics of pyramidal lattice cylinder skeleton structure

The lattice structure has obvious advantages over traditional materials in terms of light weight, energy absorption, vibration and noise reduction, and is therefore widely used in many fields such as shipping and aerospace. In this work, a cylinder skeleton structure is designed based on pyramidal lattice structure by circumferential and axial array arrangement. The load-bearing capacity of the pyramidal lattice cylinder skeleton structure under quasi-static compression and its axial vibration characteristics are investigated by numerical method. The effects of key element geometric parameters such as diameter of metal wire, circumferential angle and axial angle on the compression and vibration damping performances of the pyramidal lattice cylinder skeleton structure were investigated. The results show that the developed structure has excellent compression and vibration damping capacity. It is able to provide a pronounced damping effect in the low-frequency range of 204-367 Hz, and the attenuation intensity of elastic wave in this frequency range can be up to 20dB.

Combined stiffness characteristic of metal rubber material under vibration loads

Metal rubber is one kind of elastic cellular metal material, which is widely used in vibration isolation environment for its excellent properties of elasticity, energy dissipation, and environmental adaptability. However, the stiffness range of one single metal rubber is restricted, which limits its ability of vibration isolation, especially under the complex vibration loads. In this paper, a method of spatial overlay combination is presented to widen the range of the stiffness of metal rubber material. The contact behavior of the metal spiral rolls and the influence factors of manufacture to the stiffness are investigated according to the micro-spring theory and the energy dissipation theory. The static tests under cycling loading are conducted to obtain the average stiffness and the equivalent stiffness of the combined metal rubber. After the comparisons, the combined metal rubber has a better stiffness range than the individual element. The diameter of metal wire and the relative density of metal rubber are two important influence factors to the combined stiffness, which are verified by the experimental tests and finite element simulation.

Electrically exploding wire measurement via nanosecond laser pulse

Electrically exploding wire can be manipulated to produce nanometer-sized metal powder. Evolutionary characteristics directly affect the size of the grains formed in this process. Nanosecond laser pulses are adopted in this study to acquire photos of the explosion, wherein the explosive area has distinct margin lines within an interference fringe background. The lines are easily abstracted by recognizing disturbed sections of the stripes. The three-dimensional distribution of the metal powder at the measuring moment is determined according to the transmittance by which the laser beam penetrates the metal mist. Experimental results show that the diameter of metal wires expands from 0.3 mm to 4.7 mm 0.5 us after electrification, and expands to 28 mm by 18 us. The maximum concentration of particles decreases from 3×1021/cm3 to 1.1×1020/cm3. Throughout the expansion process, the particle concentration distribution presents multiple ring belts along the radial direction.

Study of microwave-induced metal discharge under high pressure based on spectrum analysis

ABSTRACTDischarge phenomena can occur when metals are exposed to microwave radiation. The mechanism of the discharge can be effectively studied by using spectral analysis. In this study, a reactor that can withstand long-term high pressure was used in combination with a spectrometer to investigate the effects of pressure and other parameters on the microwave metal discharge plasma. It was observed that the increase of radiation power, pressure, and metal wire diameter can have positive effects on the intensity of spectral lines. If other experimental conditions remain unchanged, the spectral lines and discharge intensity exhibit dynamic changes because the wire melts and changes its shape under the high local temperature associated with discharge. Because factors like radiation power and pressure can enhance the intensity of the plasma significantly, they can be reasonably utilized to accelerate the chemical reactions or improve the degradation rate of pollutants, e.g. in microwave wet oxidation applications.

Research on compressive mechanical properties of metal rubber and its constitutive relation model

The static compression test of metal rubber components was carried out by using the control variable method. Influences of technological parameters such as relative density and metal wire diameter as well as structural parameters such as height and bearing area on mechanical properties of metal rubber material were studied. Based on micro-element infinitesimal spring theory, one-dimensional (1D) constitutive model of metal rubber material bearing compressive load was established, and it was found by comparing with experimental data that the curve fitted well and the model was reliable, could accurately describe the mechanical behaviors of metal rubber component when bearing load. The model provides theoretical basis for further study of mechanical properties of metal rubber material. It also guides design and manufacture of metal rubber products as well as its engineering application.

A marginal contribution coefficient for sequences of nonstationary continuous Markov chains

In this work, a set of sequences of information (time series), under nonstationary regime, with continuous space state, discrete time, and a Markovian dependence, is considered. A new model that expresses the marginal transition density function of one sequence as a linear combination of the marginal transition density functions of all sequences in the set is proposed. The coefficients of this combination are denominated marginal contribution coefficients and represent how much each transition density function contributes to the calculation of a chosen transition density function. The proposed coefficient is a marginal coefficient because it can be computed instantaneously, and it may change from one time to another time since all calculations are performed before stationarity is reached. This clearly differentiates the new coefficient from well‐known measures such as the cross‐correlation and the coherence. The idea behind the model is that if a specific sequence has a high marginal contribution for the transition density function from another sequence, the first may be replaced by the latter without losing much information that means that the knowledge of few densities should be enough to recover the overall behaviour. Simulations, considering 2 chains, are presented so as to check the sensitivity of the proposed model. The methodology is also applied to a real data originated from a wire‐drawing machine whose main function is to decrease the transverse diameter of metal wires. The behaviour of the level of acceleration of each bearing in relation to the other ones is then verified.

Investigation of Shielding Properties of Yarns, Twisted with Metal Wire

The development level of the modern techniques and information technologies creates diverse nature electromagnetic fields and electric field accumulations in the human environment. Electrically conductive textiles that protect against electromagnetic waves and electric charge accumulations can be usable as protective covers for work in computer equipment rooms, measuring stands, air and gas filters and so on. One of the methods used in increase of electrical conductivity in textiles is the development of their specific structures (including the development of threads with the metal component). In this paper, unlike the currently used in the world conductive material production method, where different metal fibres are used as an additives to the main fibre composition in order to create a variety of fibres and yarns, a spun yarn with metal wire was prototyped as samples for this research and the parameters of protective properties of these samples were investigated (such as surface resistivity, vertical resistance, etc.). The protective and shielding properties of woven network with prototyped twisted electro conductive thread with a wire (metal wire diameter of 15 microns) were investigated. During the investigation the influence of the following factors, such as conductive fibre composition, electrically conductive thread distribution frequency of the longitudinal and transverse direction, on the protective shielding properties of conductive network were analyzed. The research enabled the assessment of influence of electrically conductive fibre yarn composition and its distribution in the woven mesh on protective shielding properties. DOI: http://dx.doi.org/10.5755/j01.ms.20.1.2492

Optimization of electron beam crosslinking for cables

Relationship between electron beam parameters (energy, energy spread, and electron beam distribution in irradiation zone), electrical cable geometry (thickness of polymer layers and metal wire diameter), construction (jacked, insulation) and dose distribution represented by the Dmax/Dmin coefficients were investigated. The simulations were performed using ModeCEB computer program (Lazurik et al., 2011) and then compared with the experimental data. It was demonstrated that computer simulations based on the ModeCEB program are sufficient for modeling absorbed dose distribution in the multi-layers circular objects irradiated with scanned electron beam. The calculations revealed (1) significant inhomogeneous circumferential dose distribution in polymeric sub-layers (2) relatively low influence of electron beam energy spectrum on homogeneity of irradiation and (3) high influence of beam divergence on the circumferential dose distribution.

Sound absorbing property of porous metal materials with high temperature and high sound pressure by turbulence analogy

A quantitative theoretical model is presented to investigate the sound absorbing property of porous metal materials with high temperature and high sound pressure based on Kolmogorov turbulence theory in this paper. The porous materials have a large number of anomalous pores with similar scale, and these irregular pores could be considered as quasi-periodic structure that is very similar to the small-scale turbulence. Therefore, Kolmogorov turbulence theory is adopted to analyze the wave propagation inside the porous metal materials, in which the characteristic velocity and characteristic scale can be obtained by the nondimensional analysis method. Furthermore, the acoustical pressure amplitude in the porous metal materials under high temperature and high sound pressure level can be figured out with respect to metal wire diameter, porosity, and other parameters. It is shown quantitatively that the acoustic pressure amplitude goes up with an increase in the temperature and/or the sound pressure level. This model is verified by the well agreement between the theoretical and experimental results. It could provide a reliable theoretical guidance for the applications of porous metal materials in the area of vibration and noise control under high temperature and high sound pressure level.

Study on Thermal Conductivity of Metal/Polymer Composites Based on Software ANSYS

Heat conductive materials, which widely used in the field like electronic information, electrical engineering and aerospace, are required high thermal conductivity, excellent electrical insulation, corrosive resistance, chemical stability and so on. In this paper, metal/unsaturated polyester (UP) composite is prepared to use as heat conductive material. Capacity of composite thermal transmission is analyzed by software ANSYS and experiment. The results show that the capacity of composite thermal transmission increases with increasing metal wire diameter and metal thermal conductivity. Average error between simulation and experimental data is 6.08%.

Structural Optimization Design for Metal Honeycomb Used in Continuous Waste Heat Recovery

Metal honeycomb is a kind of new plug-in unit for enhancing heat transfer, which is easy to adjust its specific surface area, excellent in heat conduction and flexible in geometrical transformation. The structures of honeycomb are optimized by FLUENT and orthogonal experiments. It is concluded that the heat exchange capability of honeycomb is most affected by the relative size representing screw pitch or screw diameter to metal wire diameter, less by the diameter of metal wire, and least by extensional rate under continuous heat recovery process. Moreover, it is found that the honeycomb has the best performance in heat transfer with metal wire diameter of 1.0 mm, relative size 8(corresponding to screw pitch and screw diameter 8.0mm) and extensional rate 0.7.

Investigation of terahertz Sommerfeld wave propagation along conical metal wire

The waveguide properties of a terahertz wave propagating along conical metal wire have been investigated under the framework of the Sommerfeld model. The effects of composed materials, metal wire diameter, and temperature on the waveguide characteristics have been shown and discussed. The numerical calculation agrees well with the experimental results shown by Ji et al., and it predicts that a metal wire waveguide shows better propagation properties at lower temperature. The ratio of energy density contours demonstrate that energy concentration at the end-tip increases with the decreasing of frequency, end-tip diameter, and radial distance from metal wire surface. As the temperature decreases, the local field intensity increases, which may result from the higher conductivity and smaller skin depth of metal at lower temperature. Because the energy density is very sensitive to temperature, the conical metal wire tip can be used to measure the changes of temperature accurately, which may be confirmed by experiment in the future.

Far-Field Radiation Patterns of Terahertz Wire Waveguides

A formula for describing far-field radiation properties of metal wire waveguides is derived based on the Fresnel-Huygens diffraction theory. According to the formula, we find that the far-field patterns are the same for waveguides with different metal materials, and the amplitude of the electric field is in inverse proportion to the radiation distance. Furthermore, the far-field radiation properties versus the terahertz (THz) wave frequency and versus the metal wire diameter are investigated. Finally, we demonstrate that direction angles and shapes of the radiation lobes can be changed by using diaphragms with different aperture sizes.

Analysis on infiltrative characteristics of deformable porous matal rubber material and paramaters identification

The effect of deformation of porous material on infiltrative performance is investigated.Based on Darcy theory and Boit principle, the Reynolds equation and mathematical expression of deformable metal rubber (MR) material under laminar flow are obtained according to the change of porosity of metal rubber. It is shown that the throttle of MR material is dependent on its porosity and diameter of metal wires. It will be of great value for the application of MR in throttle field.

Application of position-sensitive detectors to dynamic inspection of diameter of metal wires

An optical diffraction method has been applied to determine the diameter of metal wires. A simple technique using position-sensitive detectors has been developed to inspect the diameter of metal wires with the possibility of being employed on the production line, in which the wires may drift randomly with some adverse factors such as vibration and air movement.

Some properties of a fibre-reinforced nickel-base alloy

Abstract Some improvement in tensile strength and creep-rupture strength has been demonstrated on reinforcing Nimocast 713C with 20 v/o of 0·050 in. diam. tungsten wire. A more significant enhancement in both strength and specific strength was achieved using tungsten-5% rhenium as the reinforcement. Theoretically, higher specific strength at elevated temperatures could be obtained by reinforcement with molybdenum or niobium alloys provided that suitable barrier coatings can be developed to prevent interaction between matrix and reinforcement. The fatigue properties of Nimocast 713C in tension-tension loading are not measurably influenced by reinforcement with 0·050 (or 0·040) in. diam. tungsten wire, in contrast to previous reports on composites of a nickel-base alloy plus 0·010 in. diam. wires. This behaviour is interpreted in terms of the relative effectiveness of the fibre arrays of given volume fraction in arresting the propagating fatigue cracks. A limited number of tests have shown that the composites are stable in thermal cycling conditions. Chemical interaction between matrix and reinforcement occurs to a degree which is considered acceptable on fibres of greater than 0·030 in. diam. The present data indicate that the choice of refractory metal wire diameter must be made on the basis of a compromise of fatigue strength, creep-rupture strength, and long term elevated temperature stability and the ability to retain alignment during infiltration. The feasibility of using extrusion as a fabrication technique has been demonstrated.