- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Effect of Interlayer Cooling Time, Constraint and Tool Path Strategy on Deformation of Large Components Made by Laser Metal Deposition with Wire
摘要： Laser metal deposition with wire (LMD-w) is a developing additive manufacturing (AM) technology that has a high deposition material rate and efficiency and is suitable for fabrication of large aerospace components. However, control of material properties, geometry, and residual stresses is needed before LMD-w technology can be widely adopted for the construction of critical structural components. In this study, we investigated the effect of interlayer cooling time, clamp constraints, and tool path strategy on part distortion and residual stresses in large-scale laser additive manufactured Ti-6Al-4V components using finite element method (FEM). The simulations were validated with the temperature and the distortion measurements obtained from a real LMD-w process. We found that a shorter interlayer cooling time, full clamping constraints on the build plates, and a bidirectional tool path with 180° rotation minimized part distortion and residual stresses and resulted in symmetric stress distribution.
关键词： Ti-6Al-4V,part deformation,process parameter optimization,interlayer cooling time,large-scale additive manufacturing
更新于2025-09-16 10:30:52
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Coyote optimization algorithm for the parameter extraction of photovoltaic cells
摘要： In this paper, a new and powerful metaheuristic optimization technique known as the Coyote Optimization Algorithm (COA) is proposed for the parameter extraction of the PV cell/module. It is utilized to identify the parameters of the single diode and two-diode models. Inspired by the social norms adopted by the coyotes to ensure the survivability of their species, the COA possesses several outstanding merits such as low number of control parameters, ease of implementation and diverse mechanisms for balancing exploration and exploitation. For physically meaningful solutions, a set of parametric constraints is introduced to prevent the coyotes from straying outside of the predefined boundaries of the search space. Extensive tests indicate that the proposed optimizer exhibits superior accuracy compared to other state-of-the-art EA-based parameter extraction methods. It achieved root-mean-square error (RSME) as low as 7.7301E-04 A and 7.3265E-04 A, for the single-diode and two-diode models, respectively. Moreover, the algorithm maintains outstanding performance when tested on an assortment of modules of different technologies (i.e. mono-crystalline, poly-crystalline, and thin film) at varying irradiance and temperature. The standard deviations (STDs) of the fitness values over 35 runs are measured to be less than 1 × 10?5 for both models. This suggests that the results produced by the algorithm are highly consistent. With these outstanding merits, the COA is envisaged to be a competitive option for the parameter extraction problem of PV cell/module.
关键词： Equivalent circuit model,Solar photovoltaic,Evolutionary algorithm,Coyote optimization algorithm,Parameter extraction
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Suppressing the Influence of CCD Vertical Blooming on M <sup>2</sup> Determination through Deep Learning
摘要： The vertical blooming of charge-coupled device (CCD) usually occurs in silicon-based cameras, which poses great challenge to determine the M2 of near-infrared (NIR) lasers. In this paper, a new method based on deep learning technique to suppress the influence of CCD vertical blooming on M2 determination is proposed for the first time, to the best of our knowledge. Taking a step-index few-mode fiber as an example, large amounts of samples including the blooming near-field beam patterns and their corresponding M2 values are used to train the convolutional neural network (CNN), aiming at learning a fast and accurate mapping from the beam pattern to the M2 parameter. The trained CNN can then be utilized to analyse the blooming pattern recorded by CCD to determine the M2. The simulated testing results have shown that the averaged prediction error of our scheme is about 0.5% for the investigated fiber beams. As for the time cost, our trained CNN only takes about 10 ms to determine the M2 value using a common laptop computer, indicating great real-time ability with high performance.
关键词： near-infrared laser,M2 parameter,deep learning,CCD vertical blooming
更新于2025-09-16 10:30:52
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Correlation of Process Parameters and Porosity in Laser Welding of 7A52 Aluminum Alloy using Response Surface Methodology
摘要： The article presents an experimental investigation of the effect of process parameters (i.e. laser power, welding speed and defocus distance) on porosity in laser welding of 7A52 aluminum alloy. A three-factor, three-level factorial Box–Behnken design (BBD) of response surface methodology (RSM) was used to complete the design matrix with the objective of optimizing the process parameters. Multiple regression models were established to predict the correlation between the selected process parameters and porosity, and then were tested for adequacy using analysis of variance (ANOVA). The results showed that macro pores in laser welding seam were mainly keyhole induced, and porosity susceptibility was mostly dominated by welding speed. The optimal combination of process parameters is the laser power of 3.5kW, welding speed of 10.0mm/s, and the defocus distance of +4.0mm. Under the optimal process parameters, superior weld seams without macro pore were produced. The predicted porosity area fraction with RSM models was confirmed to be in good agreement with the measured values of validation experiments.
关键词： process parameter,response surface methodology,porosity,7A52 aluminum alloy,laser welding
更新于2025-09-16 10:30:52
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Nonlinear propagation of coupled surface TE and leaky TM electromagnetic waves
摘要： Propagation of the coupled electromagnetic wave, which is a superposition of TE surface and TM leaky waves, in the Goubau line (a perfectly conducting cylinder covered by a concentric dielectric layer) filled with nonlinear inhomogeneous medium is studied (if the permittivity is linear, the coupled wave does not exist). Nonlinear coupled TE–TM wave is characterised by two (independent) frequencies and two (coupled) propagation constants (propagation constants). The physical problem is reduced to a nonlinear two-parameter transmission eigenvalue problem for Maxwell’s equations. Existence of coupled TE–TM waves is proved. Intervals of localisation of propagation constants are found.
关键词： nonlinear waveguide,Nonlinear coupled TE–TM waves,Kerr nonlinearity,Maxwell’s equations,two-parameter eigenvalue problem,coupled propagation constants
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Swat, Pakistan (2019.7.24-2019.7.25)] 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Modelling of Highly Efficient Copper Zinc Tin Sulphide (CZTS) Solar Cell for Performance Improvement
摘要： Low stability, less efficiency and high cost material of the solar cell make its commercialization and manufacturing less point of attention for many researcher and industrial investor. However, the main focus of this work is to compare the investigated material i.e., CZTS with existing materials i.e., amorphous, CIGS and perovskite solar cells with respect to efficiency, cost and stability as it is one of the keen interests in photovoltaic (PV) research field. In this paper, we have presented a highly efficient, highly stable and less costly thin film solar cell with novel material i.e., Copper Zinc Tin Sulphide (CZTS) that holds a conversion efficiency, η of 18.68% with supporting short current density, Jsc= 25.258mA/cm2, open circuit voltage, Voc=0.8787 V and fill factor, FF=84.17%. Different window layer materials along with various buffer layer materials is tested and founded that fluorine tin oxide (FTO) and Indium sulphide (In2S3) are best performing candidates among all other materials. Moreover, effect of high temperature on CZTS electrical parameter is analyzed and drop in the η is observed when the temperature of the device is increased.
关键词： CZTS,Thin film solar cell,Temperature,Electrical parameter
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Dual-Parameter Modulation Leads to Chaos in An Erbium-Doped Fiber Laser
摘要： We study dual-parameter modulating how to lead to chaos in an erbium-doped fiber laser. When the pump and photon decay rate of the laser is modulated, a few paths to chaos are discussed.
关键词： Fiber laser,Dual-parameter,Chaos
更新于2025-09-16 10:30:52
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Key Parameter Identification and Optimization of Photovoltaic Power Plants Based on Genetic Algorithm
摘要： As the penetration rate of the photovoltaic power continues to grow, its impact on the stability of the power system becomes more considerable ever than before. However, due to the relatively low accuracy of the parameters, the traditional electromagnetic transient simulation used to assess the impact is biased. Therefore, it is of great importance to perform key parameter identification and optimization on a solar power plant containing many photovoltaic panels, which can avoid the problem of combination explosion. In this paper, a scheme of key parameter identification is proposed. Then, an optimization method based on genetic algorithm is also established to improve the accuracy. Simulation tests validate the effectiveness of the proposed method.
关键词： genetic algorithm,parameter identification,photovoltaic power plants,optimization
更新于2025-09-16 10:30:52
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[IEEE 2019 Innovations in Power and Advanced Computing Technologies (i-PACT) - Vellore, India (2019.3.22-2019.3.23)] 2019 Innovations in Power and Advanced Computing Technologies (i-PACT) - A Novel Optimization Method for Parameter Extraction of Industrial Solar Cells
摘要： Triple diode model is used in the present work for making a lumped parameter equivalent circuit for solar photovoltaic (PV) model. Flower pollination optimization algorithm (FPOA) is used for finding out various parameters of the solar cell. The theoretical values considering the estimation are not the same as the industrial samples of double diode model. Many current components of solar cells were not found by the two diode model correctly whereas a triple diode model can extract the data accurately. The FPOA is being used to extract different parameters of the given triple diode model. The success of the FPOA optimization process is that it performs the local and global search within the single stage to extract the parameters. Simulation is carried out and the performance of the FPOA is compared with two other optimization techniques such as differential evolution (DE) method and particle swarm optimization (PSO) method. Comparison result shows that the triple diode model including FPOA provides superior performance than the double and single diode model. Moreover, huge silicon solar cells could be explained easily by the triple diode model.
关键词： parameter extraction,diode model,solar cell,photovoltaic array,optimization algorithm
更新于2025-09-16 10:30:52
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Europium-doped boro-telluro-dolomite glasses for red laser applications: Basic insight into spectroscopic traits
摘要： Naturally abundant minerals and lanthanide-doped synthetic boro-tellurite networks have become prospective efficient laser hosts because of the synergy between them. Driven by this idea, Eu3+-doped boro-telluro-dolomite (BTD) glasses were prepared via the melt-quenching method. The spectroscopic traits of as-quenched samples were analyzed though experimental and theoretical studies. The result from the derivation of absorption spectral fitting (DASF) model demonstrated the direct allowed transition in the glasses. Moreover, the photo-luminescence spectra of the sample containing 1.0 mol% of Eu3+ (BTD1.0Eu glass) revealed a prominent red peak at 611 nm (assigned to 5D0 → 7F2 transition in Eu3+ ion) with a large stimulated emission cross section (7.15 × 10?22 cm2) and a high luminescence branching ratio (61.5%). Furthermore, the attained CIE color coordinates (0.637, 0.363), which lie near the standard red hue (0.67, 0.33), together with high quantum efficiency (92.7%) affirmed the effectiveness of BTD1.0Eu glass as a potential red laser host.
关键词： Boro-telluro-dolomite glasses,Red emission,Europium ions,Judd–ofelt analysis,Radiative parameter,Optical band-gap energy
更新于2025-09-16 10:30:52