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Finite Element ANSYS Analysis of the Behavior for 6061-T6 Aluminum Alloy Tubes under Cyclic Bending with External Pressure

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Journal of Civil Engineering and Architecture 2014年第6期8卷 673-679页

作者： Kuo-Long Lee Chen-Cheng Chung wen-fung pan Department of lnnovative Design and Entrepreneurship Management Far East University Tainan 70101 Taiwan R. O. C Department of Engineering Science National Cheng Kung University Tainan 70101 Taiwan R.O. C

In this paper, by using adequate stress-strain relationship, mesh elements, boundary conditions and loading conditions, the finite element ANSYS analysis on the behavior of circular tubes subjected to symmetrical cyclic bending with or without external pressure is discussed. The behavior includes the moment-curvature and ovalization-curvature relationships. In addition, the calculated ovalizations at two different sections, middle and right cross-sections, are also included. Experimental data for 6061-T6 aluminum alloy tubes subjected to cyclic bending with or without external pressure were compared with the ANSYS analysis. It has been shown that the analysis of the elastoplatic moment-curvature relationship and the symmetrical, ratcheting and increasing ovalization-curvature relationship is in good agreement with the experimental data.

关键词： Cyclic bending external pressure moment curvature ovalization finite element ANSYS analysis.

The Influence of Notch Depth on the Response of Local Sharp-Notched Circular Tubes under Cyclic Bending

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Journal of Applied Mathematics and Physics 2014年第6期2卷 335-341页

作者： Kuo-Long Lee Ching-Hsun Meng wen-fung pan Department of Engineering Science National Cheng Kung University Tainan

In this paper, the mechanical behavior and buckling failure of SUS304 stainless steel tubes with different local sharp-notched depths subjected to cyclic bending were experimentally investigated. It can be seen that the experimental moment-curvature relationship exhibits cyclic hardening and becomes a steady loop after a few cycles. However, the experimental ovalization-curvature relationship exhibits an increasing and ratcheting manner with the number of the bending cycles. In addition, higher notch depth of a tube leads to a more severe unsymmetrical trend of the ovalization-curvature relationship. It has been observed that the notch depth has almost no influence on the moment-curvature relationship. But, it has a strong influence on the ovalization-curvature relationship. Finally, the theoretical model proposed by Kyriakides and Shaw [1] was used in this study for simulating the controlled curvature-number of cycles to produce buckling relationship. Through comparison with the experimental data, the theoretical model can properly simulate the experimental

关键词： Circular Tube Local Sharp Notch Notch Depth Cyclic Bending

Broadband and perfect terahertz absorber based on multilayer metamaterial with cross-ring patterned structures

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Optoelectronics Letters 2025年第1期21卷 1-6页

作者： wen Jin LIU Zhanzhi WU Zhengwei pan Yu ZHANG Ying School of Science Xi'an Shiyou University Shaanxi Key Laboratory of Measurement and Control Technology for Oil and Gas Wells

Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and investigated. The structure of the absorber is double absorption layers consisting of a chromium cross ring and eight isosceles right triangles. The unique structure of the double absorbing layers excites the electric dipole multimode resonance, giving rise to high absorption performance. Meanwhile, the influence of construal parameters on absorber behavior is also discussed. The numerical results show that the absorption achieves over 90% ranging from 2.45 THz to 6.25 THz and 99% absorption in the range of 3.7—5.3 THz. The realization of broadband and perfect absorber is described using the impedance matching principle. It is obviously found that the absorber is insensitive to the high angle of incidence for both transverse electric(TE) and transverse magnetic(TM) polarizations. Compared with the former reports, this absorber has remarkable improved absorption efficiency and smaller period. The terahertz absorber may be found applications in the fields of energy capture and thermal detection.

关键词： Metamaterials

Experimental Study on the Wavelengths of Two-Dimensional and Three-Dimensional Freak Waves

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China Ocean Engineering 2023年第1期37卷 154-164页

作者： CUI Cheng pan wen-bo National Engineering Research Center for Port Hydraulic Construction Technology M.O.T.Tianjin Research Institute of Water Transport EngineeringTianjin 300456China

Freak waves are commonly characterized by strong-nonlinearity, and the wave steepness, which is calculated from the wavelength, is a measure of the degree of the wave nonlinearity. Moreover, the wavelength can describe the locally spatial characteristics of freak waves. Generally, the wavelengths of freak waves are estimated from the dispersion relations of Stokes waves. This paper concerns whether this approach enables a consistent estimate of the wavelength of freak waves. The two-(unidirectional, long-crested) and three-dimensional(multidirectional, shortcrested) freak waves are simulated experimentally through the dispersive and directional focusing of component waves, and the wavelengths obtained from the surface elevations measured by the wave gauge array are compared with the results from the linear, 3rd-order and 5th-order Stokes wave theories. The comparison results suggest that the 3rd-order theory estimates the wavelengths of freak waves with higher accuracy than the linear and 5th-order theories. Furthermore, the results allow insights into the dominant factors. It is particularly noteworthy that the accuracy is likely to depend on the wave period, and that the wavelengths of longer period freak waves are overestimated but the wavelengths are underestimated for shorter period ones. In order to decrease the deviation, a modified formulation is presented to predict the wavelengths of two-and three-dimensional freak waves more accurately than the 3rd-order dispersion relation, by regression analysis. The normalized differences between the predicted and experimental results are over 50% smaller for the modified model suggested in this study compared with the 3rd-order dispersion relation.

关键词： freak wave rogue wave wavelength three-dimension directional spread multidirectional wave

Shape-dependent hydrogen generation performance of Pt Pd bimetallic co-catalyst coupled with C_(3)N_(4)photocatalyst

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Rare Metals 2021年第12期40卷 3554-3560页

作者： wen-wen Liu Jun pan Ren-Fu Peng College of Physical Science and Engineering Yichun UniversityYichun 336000China State Key Laboratory for Powder Metallurgy Central South UniversityChangsha 410083China

The shape-dependent performance of metal cocatalysts in photocatalysis has been one of the research focal points in recent *** this study,Pt Pd/C_(3)N_(4)hybrid structures were constructed to reveal the effect of the shape of the Pt Pd bimetallic co-catalyst on the performance of photocatalytic hydrogen *** Pd nanocubes(NCs)and nanotetrahedrons(NTs)were sequentially deposited in situ on the surface of C_(3)N_(4)nanosheets,establishing a strong contact interface to ensure the smooth transfer of photoinduced ***-visible(UV-Vis)diffuse reflectance spectroscopy and photoelectrochemical experiments revealed that the Pt Pd NCs/C_(3)N_(4)photocatalyst had comparable light absorption ability and equivalent carrier separation and transfer efficiency in comparison with the Pt Pd NTs/C_(3)N_(4)photocatalyst,which excluded the influence of these factors on shape-dependent *** photocatalytic hydrogen generation results indicate that the hydrogen generation rate of the Pt Pd NCs/C_(3)N_(4)photocatalyst is 1.33 times higher than that of the Pt Pd NTs/C_(3)N_(4)photocatalyst,demonstrating that the cubic Pt Pd bimetallic co-catalyst is more conducive to hydrogen generation compared to the tetrahedral Pt Pd bimetallic co-catalyst.

关键词： PtPd bimetallic co-catalyst C_(3)N_(4) Shape Hydrogen generation Photocatalyst

Efficient algorithm for 3D bimodulus structures

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Acta Mechanica Sinica 2020年第1期36卷 143-159页

作者： Qinxue pan Jianlong Zheng Pihua wen Key Laboratory of Road Structure and Material of Ministry of Transport(Changsha) School of Traffic and Transportation EngineeringChangsha University of Science&TechnologyChangsha410114China School of Engineering and Materials Science Queen Mary University of LondonLondonE14NSUK

The bimodulus material is a classical model to describe the elastic behavior of materials with tension-compression *** to the inherently nonlinear properties of bimodular materials,traditional iteration methods suffer from low convergence efficiency and poor adaptability for large-scale structures in *** this paper,a novel 3D algorithm is established by complementing the three shear moduli of the constitutive equation in principal stress *** contrast to the existing 3D shear modulus constructed based on experience,in this paper the shear modulus is derived theoretically through a limit ***,a theoretically self-consistent complemented algorithm is established and implemented in ABAQUS via UMAT;its good stability and convergence efficiency are verified by using benchmark *** analysis shows that the calculation error for bimodulus structures using the traditional linear elastic theory is large,which is not in line with reality.

关键词： Elastic theory Bimodulus material 3D complemented algorithm Finite element method Generalized elastic law General 3D shear modulus

Aeroengine thrust estimation and embedded verification based on improved temporal convolutional network

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Chinese Journal of Aeronautics 2024年第1期37卷 106-117页

作者： Wanzhi MENG Zhuorui pan Sixin wen pan QIN Ximing SUN Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of TechnologyDalian 116024China School of Control Science and Engineering Dalian University of TechnologyDalian 116024China

Thrust estimation is a significant part of aeroengine thrust control *** traditional estimation methods are either low in accuracy or large in *** further improve the estimation effect,a thrust estimator based on Multi-layer Residual Temporal Convolutional Network(M-RTCN)is *** solve the problem of dead Rectified Linear Unit(ReLU),the proposed method uses the Gaussian Error Linear Unit(GELU)activation function instead of ReLU in residual *** the overall architecture of the multi-layer convolutional network is adjusted by using residual connections,so that the network thrust estimation effect and memory consumption are further ***,the comparison with seven other methods shows that the proposed method has the advantages of higher estimation accuracy and faster convergence ***,six neural network models are deployed in the embedded controller of the micro-turbojet *** Hardware-in-the-Loop(HIL)testing results demonstrate the superiority of M-RTCN in terms of estimation accuracy,memory occupation and running ***,an ignition verification is conducted to confirm the expected thrust estimation and real-time performance.

关键词： Thrust estimation Temporal convolutional network Embedded deployment Hardware-in-the-loop testing Ignition verification

Creep rate sensitivities of materials by a depth-sensing indentation technique

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Journal of University of Science and Technology Beijing 2006年第4期13卷 308-312页

作者： Yang Gao Shengping wen Feng pan Laboratory of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

The strain rate sensitivity to creep of single crystal Cu（110）, metal tantalum, and 128°Y-X LiNbO3 piezoelectric single crystal were measured at room temperature by MTS Nanoindenter XP. Among the three kinds of materials studied, Cu showed the highest degree of resistance to creep-induced deformation, which is followed by Ta, while the LiNbO3 single crystal deformed more readily than the others. The values of the steady-state strain rate sensitivities determined by the indentation methods are in the range of 0.002-0.006, 0.02-0.06 and 0.02-0.03 for Cu, Ta, and LiNbO3, respectively. The mechanisms for the indentation-induced creeping behavior and the factors that influenced the creeping are discussed.

关键词： indentation creep strain rate sensitivity copper tantalum LiNbO3 piezoelectric single crystal

Some Gradient Estimates and Liouville Properties of the Fast Diffusion Equation on Riemannian Manifolds

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Chinese Annals of Mathematics,Series B 2021年第4期42卷 529-550页

作者： wen WANG Rulong XIE pan ZHANG School of Mathematics and Statistics Hefei Normal UniversityHefei 230601China School of Mathematics and Statistics Chaohu UniversityChaohu 238024AnhuiChina School of Mathematical Sciences Anhui UniversityHefei 230601China School of Mathematics Sun Yat-sen UniversityGuangzhou 510275China

In the paper,the authors provide a new proof and derive some new elliptic type(Hamilton type)gradient estimates for fast diffusion equations on a complete noncompact Riemannian manifold with a fixed metric and along the Ricci flow by constructing a new auxiliary *** results generalize earlier results in the *** some parabolic type Liouville theorems for ancient solutions are obtained.

关键词： Gradient estimate Fast diffusion equation Ricci flow Liouville theorem