Number Of Wire Layers Research Articles

Investigation of the Forming Behavior of Copper Wires for the Compaction of Windings for Electric Machines

To meet the increasing demand for highly efficient electric traction drives, the compact winding process has been developed at the wbk Institute of Production Science. One key element of the process chain is the compaction of the round wire stator windings. In order to enable an estimation of the sensitivities of the influencing factors, a simplified finite element simulation model was set up in the present work. In the calculations, the number of wire layers, the layer structure and the punch stroke were selected as factors with three levels each. The evaluation was performed by means of false color images and the maximum strains and stresses in the section plane of the slots.

ЭФФЕКТИВНОСТЬ РЕГЕНЕРАЦИИ ЩЕЛЕВОГО ФИЛЬТРА

This aim of this research was to study the mechanism and efficiency of the regeneration of filtering walls by means of reverse jet blasting with a rotating nozzle during dusty gas treatment by a slotted filter. Within a series of experiments, the rotational speed of the blowing nozzle and its distance to the filtering wall, the number of wire layers and the gaps between them were varied. Air consumption for filtration and purging was measured along with the hydraulic resistance of a clean filtering wall, a wall with dust sedimentation and one following regeneration. The balance of the forces acting on the dust sediment during regeneration and the conditions for the separation of the sediment from the filtering wall were analysed, allowing the minimum velocity of the blowing jet to be mathematically defined. A dependency relation is proposed for calculating the effective working speed of the jet, which ensures efficient regeneration and minimum purging costs. The efficiency of regeneration is found to be exponentially related to the residual creep resistance index determined by the conditions of filtration and regeneration. A dependency relation is derived to calculate the regeneration coefficient, which can be recommended for determining the total hydraulic resistance of the slotted filter, taking into account the resistance of the clean filtering wall, the resistance of the dust sediment and the residual resistance of the filtering wall after regeneration.

Effective parameters on fatigue life of wire-wound autofrettaged pressure vessels

In this paper, fatigue life of wire-wound autofrettaged vessels is investigated. The mutual and simultaneous effects of cylinder thickness, autofrettage pressure, number of wire layers, wire-winding stress, and working pressure are studied in several cases. The vessel cylinder is made of high strength steel, DIN1.6959, and actual behavior in loading, unloading and reloading is considered. Modified Variable Material Properties method is used to calculate residual stresses in autofrettage process. For wire-winding, since tangent and/or Young's modulus could be changed in autofrettage unloading step or during reverse yielding according to material behavior, a capable approach is applied. Moreover, the fatigue life is determined by using ASME code equations for tick-walled pressure vessels. The results show that by combination of wire-winding and autofrettage techniques, in addition to ability of reducing production costs, infinite fatigue life could be accessible. Furthermore, optimum autofrettage pressure has significant effects on fatigue life and wire-winding efficacy.

Strain effects on the optical properties of compressively-strained InGaAs/InP multiple quantum wires

Strain effects on the optical properties of compressively-strained InGaAs/InP multiple quantum wires (QWRs) are investigated as functions of the wire thickness along the x direction, Lx, by using a six-band strain-dependent k·p Hamiltonian. In the case of QWRs with the same initial strains, the transition energy decreases with increasing number of wire layers, and its rate of decrease is shown to increase with increasing Lx. On the other hand, in the case of QWRs with different initial strains, the transition energy slightly increases with increasing number of wire layers and its rate of increase is nearly independent of Lx. The z-polarized optical matrix element for QWRs with different initial strains is shown to be much larger than that for QWRs with the same initial strains, irrespective of Lx. This can be explained by the fact that the confinement of the wavefunction in the conduction band is enhanced due to the strain effect.

Optimization of Wire-Winding and Shrink-Fit Combination in Pressure Vessel Reinforcement

In thick-walled pressure vessels design, combination of reinforcement techniques is preferred in comparison with their solo applications. Wire-winding and shrink fit are two common techniques which can be used in order to introduce beneficial compressive residual stress in the core of thick-walled pressure vessels. An optimized combination of these two techniques would lead to the integration of their advantages. The purpose of this paper is to optimize the design of a two-layered cylinder for maximum fatigue life expectancy under the combinations of wire-winding and shrink fit techniques. The layers thicknesses and radial interference of shrink fit are treated as design variables by considering different number of wire layers. The numerical optimization procedure known as the Simplex Search Method is employed to optimize the variables. Also, the fatigue life is calculated based on ASME code for high pressure vessel technology. The fatigue life was compared for different cases. The results show that by using proper combination, significant life enhancement can be achieved as high as 30 times in comparison with a wire-wound vessel. Also, it could reduce the required number of wire layers for a constant fatigue life by about 80%, which is very desirable due to difficulties of wire-winding process.

Strain relaxation effect on electronic properties of compressively strained InGaAs/InP vertically stacked multiple quantum wires

Electronic properties of compressively strained InGaAs/InP vertically stacked multiple quantum wires were investigated using an six-band strain-dependent k⋅p Hamiltonian. The strain tensor ϵyy (ϵxx) is found to relax from its initial strain. The amount of relaxation is dependent on the number of wire layers in the vertical stack and increases with the number of wire layers. The interband transition energy also decreases with the number of wire layers. This is mainly attributed to the decrease in the conduction band energy because subband energies in the valence band are nearly independent of the strain. The matrix element is shown to slightly decrease with increasing number of the wire layer in the vertical stack.

Electronic band structures of GaInAsP/InP vertically stacked multiple quantum wires with strain-compensating barriers

Energy-band structures of compressively strained GaInAsP/InP quantum wires fabricated by etching and regrowth method have been calculated using an 8 band k⋅p theory including strain relaxation. The effects of strain-compensating barriers and vertically stacking multiple wire layers on band structures are investigated. It is found that due to the dependence of strain relaxation on the amount of strain compensation in barrier regions and on the number of wire layers in the vertical stack, unlike strained quantum films, the energy-band structures of strained quantum wires are dependent on these factors. Experimentally observed wire-width dependence of the large energy blueshift in vertically stacked multiple quantum-wire structures is accurately explained using our calculations without any fitting parameter. Additional broadening in the emission spectra due to vertically stacking multiple quantum wires is found to be negligible. Our results show that strain compensation in barrier layers may be used effectively as an additional parameter to optimize practical device design.

Derivation of a new stiffness matrix for helically armoured cables considering tension and torsion

AbstractA new element stiffness matrix is derived for straight cable elements subjected to tension and torsion. The cross‐section of a cable, which may consist of many different structural components, is treated in the following as a single composite element. The derivation is quite general; consequently, the results can be used for a broad category of cable configurations. Individual helical armourning wires, for instance, may have unique geometric and material properties. In addition, no limit is placed on the number of wire layers. Furthermore, compressibility of the central core element can also be considered. The equations of equilibrium are first derived to include ‘internal’ geometric non‐linearties produced by large deformations (axial elongation and rotatioin) of a straight cable element. These equations are then linearized in a consistent manner to give a liner stiffness matrix. Linear elasticity is assumed throughout. Excellent agreement with experimental results for two different cables validates the correctness of the analysis.