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Modelling and predicting the dynamic response of an axially graded viscoelastic core sandwich beam

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Defence Technology（防务技术） 2023年第12期30卷 32-46页

作者： Suryarao Nagiredla Sharnappa Joladarashi Hemantha Kumar Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkalMangaluruKarnataka 575025India

The present study explored the influence of axial gradation of viscoelastic materials on the dynamic response of the sandwich beam for structural *** finite element(FE)formulations are used to model and investigate dynamic response of the sandwich *** classical beam theory is used to develop the FE formulations and Lagrange's approach is considered to obtain the equations of motion(EOM).FE code is developed and validated with the existing literature and also conducted the convergence study for the developed FE ***,the influence of different viscoelastic materials and boundary conditions on the dynamic response of the sandwich beam is *** different axial gradation configurations of viscoelastic materials are considered for the present work to explore the influence on natural frequency,loss factor and frequency response of the sandwich *** modeled axial gradation of viscoelastic material has displayed a considerable impact on the peak vibrational amplitude response of the sandwich beam for all the boundary conditions and these configurations improved the damping capabilities at different configurations for the structural applications.

关键词： Finite element method sandwich beam Viscoelastic material Natural frequency Loss factor Boundary condition Axial gradation

AEROELASTIC PROPERTIES OF sandwich beam WITH PYRAMIDAL LATTICE CORE CONSIDERING GEOMETRIC NONLINEARITY IN THE SUPERSONIC AIRFLOW

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Acta Mechanica Solida Sinica 2015年第6期28卷 639-646页

作者： Fengming Li Zhiguang Song Chunchun Sun College of Mechanical Engineering Beijing University of Technology P.O. Box 137 School of AstronauticsHarbin Institute of Technology Hong Du Aviation Industry Group

The equation of motion of sandwich beam with pyramidal lattice core in the supersonic flow considering geometric nonlinearity is formulated using Hamilton＇s principle. The piston theory is used to evaluate aerodynamic pressure. The structural aeroelastic properties are analyzed using frequency- and time-domain methods, and some interesting phenomena are observed. It is noted that the flutter of sandwich beam occurs under the coupling effect of low order modes. The critical flutter aerodynamic pressure of the sandwich beam is higher than that of the isotropic beam with the same weight, length and width. The influence of inclination angle of core truss on flutter characteristic is analyzed.

关键词： sandwich beam pyramidal lattice core geometric nonlinearity aeroelastic flutter supersonic flow

Analytical modeling of sandwich beam for piezoelectric bender elements

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Applied Mathematics and Mechanics(English Edition) 2007年第12期28卷 1581-1586页

作者：周燕国陈云敏丁皓江 Key Laboratory of Soft Soils and Geoenvironmental Engineering Ministry of EducationZhejiang University

Piezoelectric bender elements are widely used as electromechanical sensors and actuators, An analytical sandwich beam model for piezoelectric bender elements was developed based on the first-order shear deformation theory （FSDT）, which assumes a single rotation angle for the whole cross-section and a quadratic distribution function for coupled electric potential in piezoelectric layers, and corrects the effect of transverse shear strain on the electric displacement integration. Free vibration analysis of simplysupported bender elements was carried out and the numerical results showed that, solutions of the present model for various thickness-to-length ratios are compared well with the exact two-dimensional solutions, which presents an efficient and accurate model for analyzing dynamic electromechanical responses of bender elements.

关键词： bender elements piezoelectric sandwich beam shear correction factor,analytical model

Study On The Vibration of a sandwich beam with Smart Composites-MRF

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Study On The Vibration of a Sandwich Beam with Smart Composi...

Nonlinear vibration of Timoshenko FG porous sandwich beams subjected to a harmonic axial load

International Conference on Aerospace Materials(ICAM 2006)

作者： Bai-xiang Hu , Guo-liang Zheng, Pin-qi Xia (Nanjing University of Aeronautics and Astronautics , Nanjing, 210016,China Jiangsu University, Zhenjiang 212013, China)

Smart composite material-MRF's Theological properties such as viscosity and shear modulus can vary when subjected to different magnetic fields. This paper established the vibration model of the smart composite beam featuring MRF. The vibration analysis was finished under different magnetic field strengths using the method of complex stiffness. The experiment was performed to validate the theoretical predicted vibration responses. From both studies, the natural frequencies and loss factors of the MRF beam were shifted to a higher lever when the applied magnetic field increases. From the findings of the analysis, it is observed that MRF presents vibration control capabilities.

关键词： smart composites MRF sandwich beam natural frequency loss factor

来源： cnki会议评论

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cnki会议

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 649-662页

作者： Milad Lezgi Moein Zanjanchi Nikoo Majid Ghadiri Department of Civil Engineering Sharif University of TechnologyTehran ***Iran Civil Engineering Department K.N.Toosi University of TechnologyTehran ***Iran Faculty of Engineering Department of MechanicsImam Khomeini International UniversityQazvin ***Iran

In this study,the instability and bifurcation diagrams of a functionally graded(FG)porous sandwich beam on an elastic,viscous foundation which is influenced by an axial load,are investigated with an analytical *** do so,the Timoshenko beam theory is utilized to take the shear deformations into account,and the nonlinear Von-Karman approach is adopted to acquire the equations of ***,to turn the partial differential equations(PDEs)into ordinary differential equations(ODEs)in the case of equations of motion,the method of Galerkin is employed,followed by the multiple time scale method to solve the resulting *** impact of parameters affecting the response of the beam,including the porosity distribution,porosity coefficient,temperature increments,slenderness,thickness,and damping ratios,are explicitly *** is found that the parameters mentioned above affect the bifurcation points and instability of the sandwich porous beams,some of which,including the effect of temperature and porosity distribution,are less noticeable.

关键词： sandwich beam Timoshenko beam parametric excitation bifurcation diagrams dynamic instability

A plastic indentation model for sandwich beams with metallic foam cores

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Acta Mechanica Sinica 2011年第6期27卷 963-966页

作者： Zhong-You Xie Ji-Lin Yu Zhi-Jun Zheng CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China 230026 Hefei China Department of Civil and Architectural Engineering Tongling University 244000 Tongling China

Light weight high performance sandwich composite structures have been used extensively in various load bearing *** have shown that the indentation significantly reduces the load bearing capacity of sandwiched *** this paper,the indentation behavior of foam core sandwich beams without considering the globally axial and flexural deformation was analyzed using the principle of virtual velocities.A concisely theoretical solution of loading capacity and denting profile was *** denting load was found to be proportional to the square root of the denting depth.A finite element model was established to verify the prediction of the *** load-indentation curves and the profiles of the dented zone predicted by theoretical model and numerical simulation are in good agreement.

关键词： Indentation sandwich beam Metallic foam

Cantilever sandwich beams with pyramidal truss cores subjected to tip impact

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Science China(Technological Sciences) 2013年第1期56卷 181-187页

作者： LIU Hua LIU Hu YANG JiaLing ZHAO ShouGen School of Aeronautical Science and Engineering Beihang University

Experiments were conducted to investigate the deformation of cantilever sandwich beams with pyramidal truss cores subjected to impact by a projectile at their tips.A new technique was employed to the fabrication of sandwich beams with pyramidal truss *** a better observation of large deformation of specimens during impact process,a high-speed digital video camera was successfully used to capture the instant shapes of the deformed beams.A projectile collection device was designed and installed to avoid the projectile flying away from the beam tips after impact and thus the kinetic energy imparted to the beams was *** experiments show that the sandwich beams have a superior shock resistance compared to the monolithic beams of the same material and ***,finite element simulations were performed to gain insight into the deformations and plastic energy absorptions in the sandwich beams.

关键词： sandwich beam pyramidal truss core impact plastic

DYNAMIC RESPONSE OF ELASTIC-PLASTIC IDEAL sandwich beamS

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Acta Mechanica Sinica 1992年第1期8卷 51-60页

作者：王晓东余同希 Department of Mechanics Peking University Beijing China 100871

The dynamic response of elastic-plastic ideal sandwich beams is investigated. The plastic deformation is interpreted as a kind of general loads in the elastic beams, while the moving interfaces between elastic and plastic regions are treated as external restraint conditions. Particularly, the dynamic response of a cantilever beam is investigated using the classical method by means of the superposition of the vibration modes of elastic beams. The numerical results show that, compared with the rigid-plastic solutions, the dynamic be- havior of elastoplastic beam exhibits complex response modes. In some cases, elastic deformation has very important effects on the response mode of the beam, so it should not be ignored.

关键词： elastoplastic beam sandwich beam dynamic response response mode

Indentation of sandwich beams with metal foam core

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Transactions of Nonferrous Metals Society of China 2014年第8期24卷 2440-2446页

作者：秦庆华张建勋王正锦李慧敏郭丹西安交通大学机械结构强度与振动国家重点实验室工程力学系西安710049

The quasi-static indentation behavior of sandwich beams with a metal foam core was investigated. An analytical model was developed to predict the large deflections of indention of the sandwich beams with a metal foam core subjected to a concentrated loading. The interaction of plastic bending and stretching in the local deformation regions of the face sheet was considered in the analytical model. Moreover, the effects of the shear strength of the foam core on the indentation behavior were discussed in detail. The finite element simulations were preformed to validate the theoretical model. Comparisons between the analytical predictions and finite element results were conducted and good agreement was achieved. The results show that the membrane force dominates indentation behavior of the sandwich beams when the maximum deflection exceeds the thickness of the face sheet.

关键词： indentation sandwich beam energy absorption metal foam large deflection