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An Adaptively Filtered Precise Integration Method Considering Perturbation for Stochastic Dynamics Problems

Acta Mechanica Solida Sinica 2023年第2期36卷 317-326页

作者： Li Zhu Keqi Ye Dongwei Huang Feng Wu Wanxie Zhong State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDepartment of MechanicsFaculty of Vehicle Engineering and MechanicsDalian University of TechnologyDalian 116024China

The difficulty in solving stochastic dynamics problems lies in the need for a large number of repeated computations of deterministic dynamic equations,which has been a challenge in stochastic dynamics analysis and was discussed in this *** efficiently and accurately compute the exponential of the dynamics state matrix and the matrix functions due to external loads,an adaptively filtered precise integration method was proposed,which inherits the high precision of the precise integrationmethod,improves the computational efficiency and saves the memory ***,the perturbation method was introduced to avoid repeated computations of matrix exponential and terms due to external *** on the filtering and perturbation techniques,an adaptively filtered precise integration method considering perturbation for stochastic dynamics problems was *** numerical experiments,including a model of phononic crystal and a bridge model considering random parameters,were performed to test the performance of the proposed method in terms of accuracy and *** results show that the accuracy and efficiency of the proposed method are better than those of the existing precise integration method,the Newmark-βmethod and the Wilson-θmethod.

关键词： Precise integration method Stochastic dynamics problem Perturbation Filtered Computational efficiency

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Constructing uniform design tables based on restart discrete dynamical evolutionary algorithm

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Soft Computing 2024年第19期28卷 11515-11534页

作者： Zhao, Yuelin Wu, Feng Yang, Yuxiang Wei, Xindi Hu, Zhaohui Yan, Jun Zhong, Wanxie State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Department of Engineering Mechanics Faculty of Vehicle Engineering and Mechanics Dalian University of Technology Dalian116023 China

Generating uniform design tables (UDTs) is the first step to experimenting efficiently and effectively, and is also one of the most critical steps. Thus, the construction of uniform design tables has received much attention over the past decades. This paper presents a new algorithm for constructing uniform design tables: restart discrete dynamical evolutionary algorithm (RDDE). This algorithm is based on a well-designed dynamical evolutionary algorithm and utilizes discrete rounding technology to convert continuous variables into discrete variables. Considering the optimization of UDT is a multi-objective optimization problem, RDDE uses Friedman rank to select the optimal solution with better comprehensive comparison ranking. RDDE also utilizes a simulated annealing-based restart technology to select control parameters, thereby increasing the algorithm's ability to jump out of local optima. Comparisons with state-of-the-art UDTs and two practical engineering examples are presented to verify the uniformity of the design table constructed by RDDE. Numerical results indicate that RDDE can indeed construct UDTs with excellent uniformity at different levels, factors, and runs. Especially, RDDE can flexibly construct UDTs with unequal intervals of factors that cannot be directly processed by other designs of experiment. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Simulated annealing

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The mechanism to reform dynamic performance of an elastic wave-front in a piezoelectric semiconductor by the wave-carrier interaction induced from static biasing fields

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Applied Mathematics and mechanics(English Edition) 2023年第3期44卷 381-396页

作者： Wanli YANG Jinxi LIU Yizhan YANG Yuantai HU Department of Mechanics Hubei Key Laboratory of Engineering Structural Analysis and Safety AssessmentHuazhong University of Science and TechnologyWuhan 430074China Department of Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The propagation of an elastic wave(EW)in a piezoelectric semiconductor(PSC)subjected to static biasing fields is *** is found that there exist two coupling waves between electric field and charge *** is stimulated by the action of the polarized electric field in the EW-front on charge carriers(EFC),and the other is stimulated by the action of initial electric field in biasing fields on dynamic carriers(IEC).Obviously,the latter is a man-made and tunable wave-carrier interaction.A careful study shows that IEC can play a leading role in remaking dynamic performance of the wave-front and an inter-medium role in transferring energy from biasing fields to ***,a method is proposed to reform the EW performance by biasing-fields:reforming the dispersivity of EW-fronts by promoting competition between IEC and EFC and inverting the dissipation by the IEC to transfer energy from biasing fields to *** corresponding tuning laws on the phase-frequency characteristics of an EW show that the wave velocity can be regulated smaller than the pure EW velocity at a lowfrequency and larger than the pure piezoelectric wave velocity at a *** for regulating the amplitude-frequency characteristics of the EW by the IEC,analyses show that EWs can obtain amplification only for those with relatively high vibration frequencies(small wave lengths).The studies will provide guidance for theoretical analysis of waves propagating in PSCs and practical application and design of piezotronic devices.

关键词： piezoelectric semiconductor(PSC) elastic wave(EW) carrier movement biasing field piezotronic device

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A Peridynamics-Based Finite Element Method(PeriFEM)for Quasi-Static Fracture analysis

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Acta Mechanica Solida Sinica 2022年第3期35卷 446-460页

作者： Fei Han Zhibin Li State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian 116023China

In this paper,a peridynamics-based finite element method(PeriFEM)is proposed for the quasi-static fracture analysis,which is of the consistent computational framework with the classical finite element method(FEM).First,the integral domain of peridynamics is reconstructed,and a new type of element called peridynamic element(PE)is *** PEs are generated by the continuous elements(CEs)of classical FEM,they do not affect each ***,spatial discretization is performed based on PEs and CEs,and the linear equations about nodal displacement are established according to the principle of minimum potential ***,cracks are characterized as degradation of the mechanical properties of ***,the validity of the proposed method is demonstrated through numerical examples.

关键词： Peridynamics Finite element method Fracture Damage

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Superquadric DEM-SPH coupling method for interaction between non-spherical granular materials and fluids

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Particuology 2022年第12期71卷 20-33页

作者： Ting Qiao Lu Liu Shunying Ji State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian 116024China

The research on the coupling method of non-spherical granular materials and fluids aims to predict the particle-fluid interaction in this study.A coupling method based on superquadric elements is developed to describe the interaction between non-spherical solid particles and *** discrete element method(DEM)and the smoothed particle hydrodynamics(SPH)are adopted to simulate granular materials and *** repulsive force model is adopted to calculate the coupling force and then a contact detection method is established for the interaction between the superquadric element and the fluid *** contact detection method captures the shape of superquadric element and calculates the distance from the fluid particle to the surface of superquadric *** cases focusing on the coupling force model,energy transfer,and large-scale calculations have been implemented to verify the validity of the proposed coupling *** coupling force model accurately represents the water entry process of a spherical solid particle,and reasonably reflects the difference of solid particles with different *** the water entry process of multiple solid particles,the total energy of the water entry process of multiple solid particles tends to be *** collapse process of the partially submerged granular column is simulated and analyzed under different ***,this coupling method is suitable to simulate fluid-particle systems containing solid particles with multiple shapes.

关键词： Superquadric function Discrete element method Smoothed particle hydrodynamics Fluid-particle interaction Coupling method

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Chemical Composition Effect on Microstructures and Mechanical Properties in Friction Stir Additive Manufacturing

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Acta Metallurgica Sinica(English Letters) 2022年第9期35卷 1494-1508页

作者： Jian-Yu Li Shi-Ning Kong Chi-Kun Liu Bin-Bin Wang Zhao Zhang State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian116024China

The variation of chemical compositions can affect the mechanical property of friction stir additive manufacturing(FSAM).Quantitative characterization of the relationship between the chemical composition and the mechanical property of FSAM components is key to control the quality of FSAM *** effect of chemical composition on the mechanical property of 6 xxx series aluminum alloy FSAM joint was studied by both experimental and numerical methods.A moving heat source model was established to simulate the heat transfer in FSAM *** average grain size was calculated by Monte Carlo model,and the precipitate evolution model was used to calculate the hardness and constitutive stress-strain *** validity of the numerical model was verified by *** indicate that the hardness and yield stress of 6 xxx series aluminum alloy FSAW joint can be enhanced by increasing silicon or magnesium *** increasing the content of magnesium(silicon),the volume fraction and the mean radius of MgSi can be increased when the content of silicon(magnesium) is *** the decrease in volume fraction,the average grain size can be *** changing the weight percentage of magnesium and silicon in different layers,the hardness and yield stress along the build direction can be controlled.

关键词： Friction stir additive manufacturing Chemical composition Mechanical property Microstructure Numerical model

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Expansive Soil Stabilization by Bagasse Ash in Partial Replacement of Cement

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Journal of Renewable Materials 2023年第4期11卷 1911-1935页

作者： Waleed Awadalseed Honghua Zhao Hemei Sun Ming Huang Cong Liu State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsDalian University of TechnologyDalian116023China State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of TechnologyDalian116023China Department of Geotechnical Engineering College of Civil EngineeringHunan UniversityChangsha410082China College of Civil Engineering Fuzhou UniversityFuzhou350116China

This study examined the effects of using bagasse ash in replacement of ordinary Portland cement(OPC)in the treatment of expansive *** study concentrated on the compaction characteristics,volume change,compressive strength,splitting tensile strength,microstructure,California bearing ratio(CBR)value,and shear wave velocity of expansive soils treated with *** bagasse ash replacement ratios were used to create soil *** varying curing times of 7,14,and 28 days,standard compaction tests,unconfined compressive strength tests,CBR tests,Brazilian split tensile testing,and bender element(BE)tests were carried *** to X-ray diffraction(XRD)investigations,quartz and crystobalite make up the majority of the minerals in bagasse *** ash contains a variety of grain sizes,including numerous fiber-shaped particles,according to a scanning electronic microscope(SEM)*** all of the treated specimens with various replacement ratios,the overall additive content has not *** results of the Brazilian split tensile tests demonstrate improved tensile strength for all specimens with various replacement proportions.A lower maximum dry density and a greater optimal water content would result from the substitution of bagasse *** the replacement ratio is not more than 20%,the CBR values of the parts replaced specimens are even higher than the cement *** results of BE testing on the treated soils show that there is significant stiffness anisotropy but that it steadily diminishes with curing time and replacement *** to the study,bagasse ash is a useful mineral additive,and the best replacement ratio(CBA20)is 20%.

关键词： Expansive soil bagasse ash cement calcium silicate hydrate(CSH) stiffness anisotropy

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New analytical solutions for free vibration of embedded magneto-electro-elastic cylindrical shells with step-wise thickness variations

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Applied Mathematics and mechanics(English Edition) 2025年第3期46卷 447-466页

作者： Jufang JIA Huilin YIN Qinyu YU Jiabin SUN Xinsheng XU Zhenhuan ZHOU School of Mechanical Engineering and Automation Dalian Polytechnic UniversityDalian 116034Liaoning ProvinceChina State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentSchool of Mechanics and Aerospace EngineeringDalian University of TechnologyDalian 116024Liaoning ProvinceChina State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentSchool of Chemical EngineeringOcean and Life SciencesDalian University of TechnologyPanjin 124221Liaoning ProvinceChina

In recent years,magneto-electro-elastic(MEE)cylindrical shells with step-wise thicknesses have shown significant potential in the field of vibration energy *** aid the design of such energy harvesting devices,an accurate free vibration analysis of embedded MEE cylindrical shells with step-wise thicknesses is performed within the framework of symplectic *** using the Legendre transformation,a new known vector is defined to transform the higher-order partial differential governing equations into a set of lower-order ordinary differential ***,the original vibration analysis is regarded as an eigen problem in the symplectic space,and analytical solutions can be represented by the symplectic *** numerical examples,the new analytical solutions are compared with the existing results,and good agreement is ***,the effects of critical design parameters on free vibration characteristics are thoroughly *** numerical results can serve as benchmarks for the development of other approximate or numerical methods.

关键词： analytical solution free vibration magneto-electro-elastic(MEE)material cylindrical shell with variable thickness symplectic method

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Nonlinear dynamics of a circular curved cantilevered pipe conveying pulsating fluid based on the geometrically exact model

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Applied Mathematics and mechanics(English Edition) 2024年第2期45卷 261-276页

作者： Runqing CAO Zilong GUO Wei CHEN Huliang DAI Lin WANG Department of Engineering Mechanics School of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Wuhan 430074China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Due to the novel applications of flexible pipes conveying fluid in the field of soft robotics and biomedicine,the investigations on the mechanical responses of the pipes have attracted considerable *** fluid-structure interaction(FSI)between the pipe with a curved shape and the time-varying internal fluid flow brings a great challenge to the revelation of the dynamical behaviors of flexible pipes,especially when the pipe is highly flexible and usually undergoes large *** this work,the geometrically exact model(GEM)for a curved cantilevered pipe conveying pulsating fluid is developed based on the extended Hamilton's *** stability of the curved pipe with three different subtended angles is examined with the consideration of steady fluid *** attention is concentrated on the large-deformation resonance of circular pipes conveying pulsating fluid,which is often encountered in practical *** constructing bifurcation diagrams,oscillating shapes,phase portraits,time traces,and Poincarémaps,the dynamic responses of the curved pipe under various system parameters are *** mean flow velocity of the pulsating fluid is chosen to be either subcritical or *** numerical results show that the curved pipe conveying pulsating fluid can exhibit rich dynamical behaviors,including periodic and quasi-periodic *** is also found that the preferred instability type of a cantilevered curved pipe conveying steady fluid is mainly in the flutter of the second *** a moderate value of the mass ratio,however,a third-mode flutter may occur,which is quite different from that of a straight pipe system.

关键词： curved pipe conveying fluid pulsating fluid geometrically exact model(GEM) nonlinear dynamics parametric vibration flutter

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An adaptive artificial viscosity for the displacement shallow water wave equation

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Applied Mathematics and mechanics(English Edition) 2022年第2期43卷 247-262页

作者： Keqi YE Yuelin ZHAO Feng WU Wanxie ZHONG State Key Laboratory of Structural Analysis of Industrial Equipment Department of Engineering MechanicsFaculty of Vehicle Engineering and MechanicsDalian University of TechnologyDalianShenyang Province116023China

The numerical oscillation problem is a difficulty for the simulation of rapidly varying shallow water surfaces which are often caused by the unsmooth uneven bottom,the moving wet-dry interface,and so *** this paper,an adaptive artificial viscosity(AAV)is proposed and combined with the displacement shallow water wave equation(DSWWE)to establish an effective model which can accurately predict the evolution of multiple shocks effected by the uneven bottom and the wet-dry *** effectiveness of the proposed AAV is first illustrated by using the steady-state solution and the small perturbation ***,the action mechanism of the AAV on the shallow water waves with the uneven bottom is explained by using the Fourier *** is shown that the AVV can suppress the wave with the large wave number,and can also suppress the numerical oscillations for the rapidly varying ***,four numerical examples are given,and the numerical results show that the DSWWE combined with the AAV can effectively simulate the shock waves,accurately capture the movements of wet-dry interfaces,and precisely preserve the mass.

关键词： shallow water wave shock wave artificial viscosity displacement spurious oscillation

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