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Wave Propagation in a Magneto-Micropolar Thermoelastic Medium with Two Temperatures for Three-Phase-Lag Model 被引量:2
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作者 Samia M.Said 《Computers, Materials & Continua》 SCIE EI 2016年第4期1-24,共24页
The present paper is concerned with the wave propagation in a micropolar thermoelastic solid with distinct two temperatures under the effect of the magnetic field in the presence of the gravity field and an internal h... The present paper is concerned with the wave propagation in a micropolar thermoelastic solid with distinct two temperatures under the effect of the magnetic field in the presence of the gravity field and an internal heat source.The formulation of the problem is applied in the context of the three-phase-lag model and Green-Naghdi theory without dissipation.The medium is a homogeneous isotropic thermoelastic in the half-space.The exact expressions of the considered variables are obtained by using normal mode analysis.Comparisons are made with the results in the two theories in the absence and presence of the magnetic field as well as the two-temperature parameter.A comparison is also made in the two theories for different values of an internal heat source. 展开更多
关键词 Green-Naghdi theory internal heat source magnetic field MICROPOLAR three-phase-lag model two-temperature
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Effects of three-phase-lag on two-temperature generalized thermoelasticity for infinite medium with spherical cavity
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作者 S. BANIK M. KANORIA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第4期483-498,共16页
The thermoelastic interaction for the three-phase-lag (TPL) heat equation in an isotropic infinite elastic body with a spherical cavity is studied by two-temperature generalized thermoelasticity theory (2TT). The ... The thermoelastic interaction for the three-phase-lag (TPL) heat equation in an isotropic infinite elastic body with a spherical cavity is studied by two-temperature generalized thermoelasticity theory (2TT). The heat conduction equation in the theory of TPL is a hyperbolic partial differential equation with a fourth-order derivative with respect to time. The medium is assumed to be initially quiescent. By the Laplace trans- formation, the fundamental equations are expressed in the form of a vector-matrix differ- ential equation, which is solved by a state-space approach. The general solution obtained is applied to a specific problem, when the boundary of the cavity is subjected to the ther- mal loading (the thermal shock and the ramp-type heating) and the mechanical loading. The inversion of the Laplace transform is carried out by the Fourier series expansion tech- niques. The numerical values of the physical quantity are computed for the copper like ma- terial. Significant dissimilarities between two models (the two-temperature Green-Naghdi theory with energy dissipation (2TGN-III) and two-temperature TPL model (2T3phase)) are shown graphically. The effects of two-temperature and ramping parameters are also studied. 展开更多
关键词 two-temperature generalized thermoelasticity Green-Naghdi model three-phase-lag model spherical cavity state-space approach
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Three-phase-lag functionally graded thermoelastic model having double porosity and gravitational effect
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作者 Kapil Kumar Kalkal Aarti Kadian Sunil Kumar 《Journal of Ocean Engineering and Science》 SCIE 2023年第1期42-54,共13页
In the present article,we have used the three-phase-lag model of thermoelasticity to formulate a two dimensional problem of non homogeneous,isotropic,double porous media with a gravitational field im-pact.Thermal shoc... In the present article,we have used the three-phase-lag model of thermoelasticity to formulate a two dimensional problem of non homogeneous,isotropic,double porous media with a gravitational field im-pact.Thermal shock of constant intensity is applied on the bounding surface.The normal mode procedure is employed to derive the exact expressions of the field quantities.These expressions are also calculated numerically and plotted graphically to demonstrate and compare theoretical results.The influences of non-homogeneity parameter,double porosity and gravity on the various physical quantities are also ana-lyzed.A comparative study is done between three-phase-lag and GN-III models.Some limiting cases are also deduced from the current study. 展开更多
关键词 three-phase-lag Pores FISSURES GRAVITY Normal mode analysis
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Reflection of plane waves at the free surface of fiber-reinforced orthotropic thermoelastic rotating half-space with three-phase-lag model
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作者 Suresh Kumar Sheokand KapilKumar Kalkal Sunita Deswal 《Journal of Ocean Engineering and Science》 SCIE 2021年第3期237-247,共11页
The present article is concerned with the propagation of plane waves in a homogeneous,fiber-reinforced orthotropic thermoelastic ro-tating half-space in the context of three-phase-lag model.There exist three coupled w... The present article is concerned with the propagation of plane waves in a homogeneous,fiber-reinforced orthotropic thermoelastic ro-tating half-space in the context of three-phase-lag model.There exist three coupled waves,namely,quasi-longitudinal P-wave(qP),quasi-longitudinal thermal wave(qT)and quasi-transverse wave(qSV)in the medium.The reflection coefficients are computed numerically with the help of MATLAB programming and are depicted graphically to show the effects of rotation,fiber-reinforcement and phase lag parameters.The expressions of energy ratios have also been obtained in explicit form and are shown graphically as functions of angle of incidence.It has been verified that during reflection phenomena,the sum of energy ratios is equal to unity at each angle of incidence.Effect of anisotropy is depicted on velocities of various reflected waves.Some particular cases of interest have also been inferred from the present investigation. 展开更多
关键词 Fiber-reinforcement ORTHOTROPIC REFLECTION Generalized thermoelasticity three-phase-lag Rotation.
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三相有限延迟型非Fourier介质热力耦合传播模式和群速度 被引量:2
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作者 张晓敏 张培源 彭向和 《应用力学学报》 EI CAS CSCD 北大核心 2005年第4期511-516,共6页
给出了三相有限延迟型非Fourier介质的热力耦合传播的基本解,得到传播速度及其界限的结论。正值对数温升率相应的基本解表示温度和变形的指数分布形式较一定速度的传播,其传播速度与对数温升率有关;各个对数温升率相应的传播模式的总和... 给出了三相有限延迟型非Fourier介质的热力耦合传播的基本解,得到传播速度及其界限的结论。正值对数温升率相应的基本解表示温度和变形的指数分布形式较一定速度的传播,其传播速度与对数温升率有关;各个对数温升率相应的传播模式的总和,不存在恒定的传播速度,而是两个群速度。两个群速度都是有界数集。在热力无耦合情况下,一个群速度蜕化为具有恒定数值的膨胀波速,即第一声速;另一个群速度蜕化为温度波波速。后者也是一个群速度,其上确界为CV型介质温度波速的0.6065倍。 展开更多
关键词 非Fourier定律 三相有限延迟 热力耦合 温升率 群速度
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基于FBD法的三相四桥臂APF的研究 被引量:2
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作者 时国平 许卫兵 王长春 《自动化与仪器仪表》 2010年第5期22-24,共3页
针对三相四线制配电网中零线上电流的抑制以及谐波检测的简便性,提出了基于FPD法检测谐波的三相四桥臂并联型有源电力滤波器解决方案。本文详细阐述了三相四桥臂并联型有源电力滤波器的工作原理、检测和控制方式。仿真和实验结果验证了... 针对三相四线制配电网中零线上电流的抑制以及谐波检测的简便性,提出了基于FPD法检测谐波的三相四桥臂并联型有源电力滤波器解决方案。本文详细阐述了三相四桥臂并联型有源电力滤波器的工作原理、检测和控制方式。仿真和实验结果验证了此方法的可行性。 展开更多
关键词 三相四桥臂 有源电力滤波器 零线电流 FPD法
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双凸极永磁电机中五种PWM控制方式下的电流拖尾现象 被引量:5
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作者 秦海鸿 赵朝会 +1 位作者 王慧贞 严仰光 《电工技术学报》 EI CSCD 北大核心 2006年第8期36-43,共8页
基于12/8极转子斜槽式双凸极永磁电机,简要介绍了其基本工作原理,然后分别在五种基本的PWM控制方式下,对一周期每工作区间内关断相绕组的工作情况进行了研究。研究表明,除PWM双斩控制方式外,其余四种PWM单斩控制方式下,均会在关断相绕... 基于12/8极转子斜槽式双凸极永磁电机,简要介绍了其基本工作原理,然后分别在五种基本的PWM控制方式下,对一周期每工作区间内关断相绕组的工作情况进行了研究。研究表明,除PWM双斩控制方式外,其余四种PWM单斩控制方式下,均会在关断相绕组中出现一类特殊的电流拖尾现象。本文对电流拖尾产生机理进行了详细推导和阐述,给出了不同PWM控制方式下绕组电流的典型波形及分析,探讨了电流拖尾对电机运行的影响。基于四种PWM单斩方式下电流拖尾产生机理的相似性,文末以单斩桥臂上管的H_pwm-L_on型控制方式为例,给出相关实验结果,验证了理论分析及结论的正确性。 展开更多
关键词 双凸极永磁电机机理 电流拖尾 PWM 三相桥式 单斩 双斩
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双DSP控制的三相四桥臂静止同步补偿器的研究
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作者 时国平 钱叶旺 +1 位作者 许卫兵 韩春宝 《电力电子技术》 CSCD 北大核心 2011年第6期35-37,共3页
针对三相四线制配电网的无功、谐波检测的实时性和零线电流抑制问题,采用了双DSP控制的三相四桥臂静止同步补偿器(STATCOM)解决方案。谐波和无功电流检测方式采用FBD法,可减轻DSP计算量;谐波和无功电流的控制采用电流直接控制方式,其响... 针对三相四线制配电网的无功、谐波检测的实时性和零线电流抑制问题,采用了双DSP控制的三相四桥臂静止同步补偿器(STATCOM)解决方案。谐波和无功电流检测方式采用FBD法,可减轻DSP计算量;谐波和无功电流的控制采用电流直接控制方式,其响应速度和控制精度相比间接控制方式有很大提高。系统的数字控制采用双DSP控制方式,一片DSP主要负责信号数据采集,另一片DSP主要负责指令电流的运算,可大幅提高系统的运行速度,保证了STATCOM补偿的实时性。介绍了三相四桥臂STATCOM的检测和控制方式,并对检测原理作了具体的算法推导;绘制了系统的硬件构成图和软件主程序流程图;对系统进行了仿真和实验,STATCOM投入后,系统侧的电流相位可以很好地跟踪电压相位,无功得到很好补偿,电流波形是正弦波,中线电流接近零,谐波和零线电流得到很好的抑制。 展开更多
关键词 静止同步补偿器 三相四桥臂 数字信号处理器
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抑制配电网三相不平衡的柔性接地装置控制方法 被引量:13
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作者 曾祥君 李理 +3 位作者 喻锟 陈朵红 李建华 车晓涛 《电力科学与技术学报》 CAS 北大核心 2020年第3期19-28,共10页
为提高现有柔性接地装置抑制配电网三相不平衡的稳定性与信号跟踪能力,提出一种基于改进双闭环控制策略的柔性接地装置控制方法。通过对控制系统进行建模和分析,并提出注入电流的控制策略。该策略在双闭环控制的基础上,采用电流内环PI... 为提高现有柔性接地装置抑制配电网三相不平衡的稳定性与信号跟踪能力,提出一种基于改进双闭环控制策略的柔性接地装置控制方法。通过对控制系统进行建模和分析,并提出注入电流的控制策略。该策略在双闭环控制的基础上,采用电流内环PI控制和电压外环滞后网络控制。将中性点电压参考值设置为零,并以其作为控制目标,实时比较参考值和中性点电压反馈量之间差值。该差值经过串联滞后校正环节后可作为电流内环产生参考电流,电流理论参考值与实际测量值构成的偏差作为PI校正环节的输入量,实现对输出电流的目标控制,有效提高电流的稳定裕度,缩短了输出与输入信号的跟踪时间。系统仿真分析结果表明该方法在三相不平衡过电压抑制中性能良好,能够将配电网中性点不平衡过电压精确抑制到零。 展开更多
关键词 三相不平衡 柔性接地装置 注入电流控制 PI校正 滞后环节
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基于移相全桥技术的PFC三相四线AC/DC变换器 被引量:2
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作者 赵涛 王相綦 尚雷 《电工技术学报》 EI CSCD 北大核心 2004年第4期70-75,共6页
基于全桥移相(PSFB)控制技术,提出一种可实现交流输入与直流输出隔离的三相四线AC/DC变换器。对基本结构进行了理论分析和实验验证。理论和实验表明该变换器有效提高功率因数,明显改善滞后臂的软开关。
关键词 三相四线 AC/DC变换器 隔离 功率因数校正 滞后臂 软开关改善
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Generalized Thermo Elasticity in an Infinite Nonhomogeneous Solid Having a Spherical Cavity Using DPL Model
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作者 Ahmed Elsayed Abouelrega 《Applied Mathematics》 2011年第5期625-632,共8页
The induced temperature, displacement, and stress fields in an infinite nonhomogeneous elastic medium having a spherical cavity are obtained in the context dual-phase-lag model. The surface of the cavity is stress fre... The induced temperature, displacement, and stress fields in an infinite nonhomogeneous elastic medium having a spherical cavity are obtained in the context dual-phase-lag model. The surface of the cavity is stress free and is subjected to a thermal shock. The material is elastic and has an in?homogeneity in the radial direction. The type of non homogeneity is such that the elastic constants, thermal conductivity and density are propor?tional to the nth power of the radial distance. The solutions are obtained analytically employing the Laplace transform technique. The numerical inversion of the transforms is carried out using Fourier series expansions. The stresses, temperature and displacement are computed and presented graphically. A comparison of the results for different theories is presented. 展开更多
关键词 GENERALIZED THERMO ELASTICITY NONHOMOGENEOUS Functionally Graded Material (FGM) Laplace Transform three-phase-lag MODEL
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Generalized thermoelastic interaction in functional graded material with fractional order three-phase lag heat transfer 被引量:3
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作者 Ibrahim A.Abbas 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1606-1613,共8页
The present work is concerned with the solution of a problem on thermoelastic interactions in a functional graded material due to thermal shock in the context of the fractional order three-phase lag model. The governi... The present work is concerned with the solution of a problem on thermoelastic interactions in a functional graded material due to thermal shock in the context of the fractional order three-phase lag model. The governing equations of fractional order generalized thermoelasticity with three-phase lag model for functionally graded materials(FGM)(i.e., material with spatially varying material properties) are established. The analytical solution in the transform domain is obtained by using the eigenvalue approach.The inversion of Laplace transform is done numerically. The graphical results indicate that the fractional parameter has significant effects on all the physical quantities. Thus, we can consider the theory of fractional order generalized thermoelasticity an improvement on studying elastic materials. 展开更多
关键词 three-phase lag model fimctionally graded materials fractional calculus generalized thermoelasticity
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三相滞后对有球形空腔无限介质双温广义热弹性的影响
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作者 S·班尼克 M·卡诺尼亚 +1 位作者 海治 张禄坤 《应用数学和力学》 CSCD 北大核心 2012年第4期460-474,共15页
就各向同性的无限弹性体,具有一个球形空腔时,从双温广义热弹性理论(2TT)角度,研究三相滞后热方程的热弹性相互作用问题.在三相滞后理论中,热传导方程是一个含时间四阶导数的、双曲型的偏微分方程.假设无限介质初始时静止,通过Laplace变... 就各向同性的无限弹性体,具有一个球形空腔时,从双温广义热弹性理论(2TT)角度,研究三相滞后热方程的热弹性相互作用问题.在三相滞后理论中,热传导方程是一个含时间四阶导数的、双曲型的偏微分方程.假设无限介质初始时静止,通过Laplace变换,将基本方程用向量矩阵微分方程的形式表示,然后通过状态空间法求解.将得到的通解应用于特殊问题:空腔边界上承受着热荷载(热冲击和坡型加热)和力学荷载.使用Fourier级数展开技术,实现Laplace变换的求逆.计算了铜类材料物理量的数值解.图形显示,两种模型:带能量耗散的双温Green-Naghdi理论(2TGNⅢ)和双温三相滞后模型(2T三相)明显不同.还对双温和坡型参数的影响进行了研究. 展开更多
关键词 双温广义热弹性 Green-Naghdi模型 三相滞后模型 球形空腔 状态空间法
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基于Green-Naghdi模型与三相延迟模型的耦合热弹性波传播
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作者 王红 李月秋 +3 位作者 李晓红 魏蕴波 方晓燕 林春丽 《数学的实践与认识》 2021年第2期213-223,共11页
研究了基于G-N模型与三项延迟模型的热弹性波的传播特征.在各种广义热弹性理论中,热位移概念的引入使得G-N模型具有独特性质而引起广泛的关注和应用.基于G-N模型,最近一个三相延迟模型被提出.主要研究了这两种模型下第一和第二声波(耦... 研究了基于G-N模型与三项延迟模型的热弹性波的传播特征.在各种广义热弹性理论中,热位移概念的引入使得G-N模型具有独特性质而引起广泛的关注和应用.基于G-N模型,最近一个三相延迟模型被提出.主要研究了这两种模型下第一和第二声波(耦合热弹性波)的色散和衰减特性,分析了温度场和位移场在两种模型下的振幅比和相位差.结果发现三相延迟模型更为通用和灵活,应得到更多的关注与应用. 展开更多
关键词 热弹性 Green-Naghdi模型 三相延迟模型 色散和衰减
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