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Experimental Study of Helical Milling Carbon Fiber Reinforced Plastics by variable parameters

EXPERIMENTAL TECHNIQUES 2024年第2期48卷 343-357页

作者： Jiao, A. Zhang, Y. Zhang, J. Li, J. Univ Sci & Technol Liaoning Coll Mech Engn & Automat Anshan 114041 Peoples R China Estun Automat Grp Nanjing 210000 Peoples R China

In order to significantly reduce the defects of hole-making on Carbon Fiber Reinforced Plastics (CFRP), a scheme on the variable parameter helical milling experiments was carried out. First, the helical milling process was analyzed. Second, using the response surface methodology (RSM) in the experiments, the max exit tear value, aperture diameter and surface roughness Ra at the intermediate area were analyzed and the optimum combination of parameters was obtained: spindle speed 8962 r/min, helical speed 60 r/min, and pitch 0.207 mm at the hole entry and exit areas;spindle speed 6242 r/min, helical speed 87 r/min, and pitch 0.205 mm at the hole intermediate area. Last, the effect of milling direction on hole-making was obtained: up milling at the hole entry and exit areas and down milling at the hole intermediate area. The superiority of variable parameter helical milling experiment was verified: there were fewer defects such as burrs and tears at hole entry and exit areas;and the surface roughness Ra was 6.39% lower, the aperture deviation was from + 0.011 mm to -0.007 mm at the hole intermediate area. Therefore, the quality of hole-making by the variable parameter helical milling scheme was significantly improved.

关键词： variable parameters Helical milling CFRP Surface roughness Ra RSM

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An Efficiency Improvement Method for the Small Air Gap Wireless Power Transfer System With variable parameters

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IEEE TRANSACTIONS ON POWER ELECTRONICS 2023年第11期38卷 13443-13453页

作者： Jia, Yahui Wang, Zhihui Tang, Chunsen Zhao, Lei Li, Xiaofei Wang, Cheng Chongqing Univ Sch Automat Chongqing 401331 Peoples R China

The magnetic coupling wireless power transfer (MC-WPT) system for automatic guided vehicles is characterized by a small and unfixed air gap, which leads to significant changes in self- and mutual inductance of the magnetic coupler. In this article, an efficiency improvement method is proposed for the MC-WPT system with variable self- and mutual inductance parameters. By optimizing the design of magnetic couplers and compensation parameters, a wide range of zero-voltage switching (ZVS) operation and minimization of the reactive current are achieved. The self-inductance variation is utilized to provide a variable system input impedance, which expands the ZVS operation range with phase-shift modulation. Meanwhile, the reactive current of the resonant tank in the entire air gap range can be reduced to the minimum when the tuning parameters are designed properly. Compared with the traditional hybrid control strategies, the proposed method offers a simpler control scheme and eliminates the adverse effects caused by the self-inductance variation. A laboratory prototype is built to verify the theoretical analysis. The experimental results show that the system achieves ZVS operation and minimum reactive current within an air gap range of 20-50 mm, and efficiency reaches 91.2%.

关键词： Efficiency improvement magnetic coupling wireless power transfer (MC-WPT) variable parameters zero-voltage switching (ZVS)

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Seismic response of a stilted mid-story isolated structure in mountainous areas based on variable parameters soil-structure-interaction effect

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STRUCTURES 2023年 51卷 707-717页

作者： Wan, Feng Zhou, Wangwang Liu, Dewen Huo, Yiran Li, Hui Luo, Xiaoxuan Yao, Shunzhong Southwest Forestry Univ Coll Civil Engn Kunming 650024 Peoples R China Huazhong Univ Sci & Technol Sch Civil Hydraul Engn Wuhan 430074 Peoples R China

Many mountainous areas in the world are vulnerable to earthquakes. The geology of mountainous areas is complicated, the terrain fluctuates wildly, and the dynamic characteristics differ from those of flat areas. The soil-structure-interaction (SSI) effect has rarely been considered in studies of mountain structures. Theoretical research on SSI in mountainous areas lags behind engineering applications. It is suggested that SSI should be considered in mountainous areas. In this study, three mountain structure models were established: a stilted mid-story isolated structure without SSI effect, a stilted mid-story isolated structure with traditional SSI effect and a stilted mid-story isolated structure with variable parameters SSI effect. The earthquakes were input in the direction of down and transverse slopes. The results indicate that the seismic response of the stilted mid-story structure with SSI effect is larger than that of the stilted mid-story structure without SSI effect in mountainous areas. The seismic response of the stilted mid-story structure with variable parameters SSI effect in mountainous areas is more accurate and reliable. The seismic response is significantly affected by the changes of soil stiffness and damping. The maximum stress values of the three structures appear at the stilted short columns and the ends of the connected beams. As the soil softens, the seismic response of the stilted mid-story isolated structure with SSI effect in mountainous areas increases. When earthquakes are input in the transverse slope direction, the soil twists, aggravating structural torsion.

关键词： variable parameters SSI effect Stilted structures in mountainous areas Mid-story isolated Structural damage Structural dynamic response

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A Dual-Adaptive PID Control Approach for Nonlinear Processes with variable parameters 7

A Dual-Adaptive PID Control Approach for Nonlinear Processes...

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2024 Congress of Argentina

作者： Vega, Sebastian Bravo, Matias Camacho, Oscar Univ San Francisco Quito Colegio Ciencias & Ingn Quito 170157 Ecuador

ISBN: (纸本)9798350365948;9798350365931

This study compares a Dual-Adaptive PID controller with an existing adaptive PID controller, tested on nonlinear systems with variable parameters under changes in set point, disturbances, and noise. Performance metrics such as settling time, overshoot, Integral of Squared Error (ISE), and Integral of Squared Control Output (ISCO) were evaluated. The results demonstrate that the Dual-Adaptive PID controller achieves superior performance across these metrics, indicating its effectiveness in handling the complexities of nonlinear systems.

关键词： PID Adaptive PID Dual-Adaptive nonlinear processes variable parameters

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variable parameters t Chart: An Application in Automobile Engine Piston Rings Manufacturing Process

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INTERNATIONAL JOURNAL OF RELIABILITY QUALITY AND SAFETY ENGINEERING 2024年第6期31卷

作者： Saha, Sajal Khoo, Michael B. C. Mim, Faijun Nahar Chatterjee, Kashinath Yeong, Wai Chung Univ Sains Malaysia Sch Math Sci Gelugor 11800 Penang Malaysia Int Univ Business Agr & Technol Dept Math Dhaka Bangladesh Mawlana Bhashani Sci & Technol Univ Dept Stat Tangail Bangladesh Augusta Univ Dept Populat Hlth Sci Div Biostat & Data Sci Augusta GA USA Monash Univ Sch Sci Subang Jaya 47500 Selangor Malaysia

The (X) over bar type charts possess a drawback as they may falsely indicate out-of-control (OOC) situations when the process standard deviation is unstable. They are not robust against estimation errors or variations in the process standard deviation. To overcome this setback, the tt type charts were developed. This research introduces the variable parameters (VP) tt chart for effectively monitoring the process mean. This study encompasses the implementation, optimal designs and performance evaluation of the proposed VP t chart. The average time to signal (ATS), standard deviation of the time to signal (SDTS) and expected average time to signal (EATS) criteria are used to assess and compare the performance of the VP tt chart with existing charts, such as Shewhart (SH) t, synthetic (Syn) t, side-sensitive group runs (SSGR) t, exponentially weighted moving average (EWMA) t and variable sampling interval (VSI) EWMA t charts. From extensive analysis, we observe that the VP t chart outperforms the SH t, Syn t and SSGR t charts for all sizes of mean shifts. However, the EWMA t and VSI EWMA t charts exhibit better performance for small shifts. Additionally, to demonstrate the implementation and usage of the proposed VP tt chart, we present a real-world manufacturing example.

关键词： t type charts variable parameters average time to signal standard deviation of the time to signal expected average time to signal

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α -FRACTAL FUNCTION WITH variable parameters: AN EXPLICIT REPRESENTATION

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FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY 2024年第2期32卷 2440008-2440008页

作者： Priyanka, T. M. C. Serpa, C. Gowrisankar, A. Vellore Inst Technol Sch Adv Sci Dept Math Vellore 632014 Tamil Nadu India Univ Lisbon Fac Ciencias Ctr Matemat Aplicacoes Fundamentais & Invest Opera ISEL Inst Super Engn Lisboa P-1749016 Lisbon Portugal

In this paper, new results on the alpha-fractal function with variable parameters are presented. The Weyl-Marchaud variable order fractional derivative of an alpha-fractal function with variable parameters is examined by imposing certain conditions on the scaling factors. Following the investigation of fractional derivative, the definite integral of the alpha-fractal function with variable parameters is evaluated for various intervals in the prescribed domain. Finally, an explicit structure for the alpha-fractal function is provided using the base q representation of numbers.

关键词： alpha-Fractal Function variable parameters Fractional Derivative Definite Integral Base Representation

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variable sample size and sampling interval (VSSI) and variable parameters (VP) run sum charts for the coefficient of variation

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QUALITY TECHNOLOGY AND QUANTITATIVE MANAGEMENT 2024年第2期21卷 177-199页

作者： Yeong, Wai Chung Tan, Yen Yoon Lim, Sok Li Khaw, Khai Wah Khoo, Michael Boon Chong Sunway Univ Sch Math Sci Petaling Jaya Malaysia Taylors Univ Fac Business & Law Sch Accounting & Finance Subang Jaya Malaysia Univ Sains Malaysia Sch Management George Town Malaysia Univ Sains Malaysia George Town Malaysia Sunway Univ Sch Math Sci Petaling Jaya 47500 Malaysia

This paper improves the sensitivity of the existing run sum chart for shifts in the coefficient of variation (gamma) by proposing two types of adaptive schemes, i.e. the variable sample size and sampling interval (VSSI) and variable parameter (VP) schemes. The VSSI run sum gamma chart varies the sample size (n) and sampling interval (h), while the VP run sum gamma chart varies not only n and h but also the size of each region of the run sum chart. The operations, as well as formulae and algorithms to optimize the charts' performance, are developed. Subsequently, tables of optimal charting parameters are obtained. The VP run sum gamma chart is shown to outperform the VSSI run sum gamma chart. The proposed charts are also shown to outperform the variable sampling interval (VSI) run sum, variable sample size (VSS) run sum, and the VSSI, VSS and VSI gamma charts, as well as the VSS and VSI EWMA gamma(2) charts for moderate and large shift sizes. Implementation on an actual industrial example shows the sensitivity of the proposed charts towards small shifts.

关键词： Average time to signal coefficient of variation run sum variable parameters variable sample size and sampling interval

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A variable parameters auxiliary information based quality control chart with application in a spring manufacturing process: The Markov chain approach

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QUALITY ENGINEERING 2021年第2期33卷 252-270页

作者： Chong, Nger Ling Khoo, Michael B. C. Castagliola, Philippe Saha, Sajal Mim, Faijun Nahar Univ Sains Malaysia Sch Math Sci Minden 11800 Penang Malaysia Univ Nantes LS2N UMR CNRS 6004 Nantes France Int Univ Business Agr & Technol Dept Math Dhaka Bangladesh

In this paper, a new variable parameters chart for the process mean with a statistic that integrates information from the study and auxiliary variables is proposed. The proposed variable parameters chart with auxiliary information (AI) (abbreviated as VP-AI) is optimally designed to minimize the out-of-control steady-state (i) average time to signal (ATS(1)) and (ii) expected average time to signal (EATS(1)) values when the mean shift sizes are known and unknown, respectively. The Markov chain approach is adopted to derive the formulae of the performance measures ATS(1), standard deviation of the time to signal (SDTS1) and EATS(1). The VP-AI chart significantly outperforms the standard VP chart;thus, justifying the incorporation of auxiliary information to enhance the ability of the VP chart. The VP-AI chart is also compared with the Shewhart AI, synthetic AI, exponentially weighted moving average (EWMA) AI, run sum AI and variable sample size and sampling interval (VSSI) AI charts. The VP-AI chart significantly outperforms the Shewhart AI, synthetic AI and VSSI AI charts for all levels of shifts. Meanwhile, the VP-AI chart outperforms the EWMA AI and run sum AI charts for most shifts. The VP-AI chart is found to be more robust than the EWMA-AI chart when the correlation coefficient is misspecified or the bivariate normality assumption is violated as long as the size of the shift is moderate or large. A real application which monitors spring elasticity is used to illustrate the VP-AI chart's implementation.

关键词： control chart variable parameters auxiliary information average time to signal expected average time to signal

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Non-uniform subdivision schemes of ωB-spline curves and surfaces with variable parameters?

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COMPUTER-AIDED DESIGN 2023年 154卷

作者： Lamnii, A. Nour, M. -y. Sbibih, D. Zidna, A. Abdelmalek Essaadi Univ LaSAD ENS Tetouan 93030 Morocco Hassan First Univ Settat Fac Sci & Tech Lab MISI Settat Morocco Univ Mohammed 1 LANO Lab FSO Oujda Morocco Univ Lorraine LGIPM F-57000 Metz France

In this paper, we propose a new non-uniform subdivision scheme that includes a tension parameters sequence. Each tension parameter of the sequence is assigned at each edge of the initial control polygon. The proposed scheme can produce limiting curves that are more consistent with the original data points and the control polygon. It has also the advantage of generating a wide variety of shapes for the limiting curves. Moreover, to produce smooth limit surfaces, the proposed scheme is firstly extended to tensor-product surfaces, then to meshes of arbitrary topology. The convergence and smoothness of the proposed scheme are proven. Numerical results that illustrate the advantages of the proposed non-uniform scheme are given. (c) 2022 Elsevier Ltd. All rights reserved.

关键词： Non -uniform subdivision scheme ?B-spline variable parameters Tensor -product Arbitrary topology Smoothness

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Peristaltic flow of a hyperbolic tangent fluid with variable parameters

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RESULTS IN ENGINEERING 2023年 17卷

作者： Elogail, M. A. Arab Acad Sci Technol & Maritime Transport AASTMT Dept Basic & Appl Sci Sharjah Branch Sharjah U Arab Emirates

This article investigates the peristaltic flow of a hyperbolic tangent fluid with variable viscosity and thermal conductivity through a vertical asymmetric channel. Consideration is given to the effects of viscous dissipation, chemical reactions, and convection heat at the channel walls. The relevant mathematical modeling incorporates lubrication approximation. The resulting system of highly non-linear differential equations is converted non-dimensional via suitable quantities. The non-dimensional parameters formed in viscosity or thermal conduc-tivity are treated as variables. This treatment is the fundamental recommendation of the current study to avoid obtaining unrealistic results. Using the built-in package (ParametricNDSolve) in the computing program Math-ematica, the analysis is performed numerically, and the results for temperature and concentration profiles in addition to the trapping phenomenon are shown through graphs. The major findings show that an increase in temperature is associated with a decrease in viscosity, whereas the opposite (unrealistic) behavior is maintained when the variable parameters are treated as constants. Results also indicate that the thermal conductivity at relatively low temperatures is enhanced, whereas the opposite trend is noted at higher temperature values. Potential applications for the current work include cooling techniques used in medical and industrial applica-tions, food processing, and blood flow in microvessels.

关键词： Peristalsis variable viscosity variable thermal conductivity Convective boundary conditions variable parameters

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