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So far excavator retrofitting breaking hammer is commonly applied to impact breaking operation on rock, mountain and building body in engineering field. In practical operation fracture of the movable excavator arm frequently occurs. This thesis, in terms of dynamics, considers the breaking machine under three typical working conditions and aims at respective load solutions for the hinge point of the movable arm under each working condition. Modal analysis and harmonic response for the movable arm is conducted by means of finite element software. Analysis shows that the movable arm would not resonate at relatively high frequencies and external excitation load affects the movable arm noticeably at low frequencies. Damping increase of the working device of the breaking machine is needed to enable the external excitation frequency to avoid the primary and secondary inherent frequencies, and thus reduce the resonation opportunity of the movable arm.

The 2019-nCoV is ravaging the world, taking lots of lives, and it is emergent to find a solution to deal with this novel pneumonia. This paper provides a potential treatment for COVID-19 utilizing resonance to destroy the infection ability of 2019-nCoV. Firstly, the geometry size of 2019-nCoV is scaled up by 10,000 times. The additional mass is used to represent the effect of the fluid around a spike protein. The finite element analysis (FEA) is used to study the modal characteristics of the tuned 2019-nCoV model and mistuned 2019-nCoV model in blood, respectively. Based on FEA, the lumped parameter mechanical model of 2019-nCoV is established. Then, the dynamic responses of mistuned 2019-nCoV are investigated through harmonic response and dynamical analysis. Finally, a potential method utilizing 360° sweep excitation to cure COVID-19 is put forward.

First, the flexibility matrix of the rolling mill interfaces is extracted with Jetmundsen substructure synthesis method, and the power flow mode of the interfaces is obtained and discussed when the...

Stiffened plates are employed in various engineering structures including aerospace, civil, naval, etc. These structures may be subjected to harmonic loads. Therefore, it is essential to understand the harmonic response of a cracked stiffened structure. This study presents the effects of the crack location on the free vibration and harmonic response of the stiffened plates. For this purpose, horizontal and vertical cracks are modelled throughout the fixed from two-side structure. The analyses are performed via the Finite Element Method and the Mode Superposition technique. The natural frequencies and the displacement responses of the cracked and healthy structures are obtained and interpreted. It is concluded that a horizontal crack can decrease the third natural frequency by 60% as it is located in the center of the stiffened plate that is fixed from its non-stiffened edges. Thus, the displacement response of the stiffened structures is increased by 18% in the presence of the side horizontal or vertical cracks, which are located at the free ends of the stiffened structures no matter which boundary condition is considered.

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Carbon nanotubes are used in several engineering applications because of their superior mechanical properties. Scientific works still need to be carried out, especially on their dynamic response. These studies mainly focus on modal analysis, considering zigzag and armchair nanotubes, and sometimes, varying chirality. However, these works do not present any results on the steady-state responses. Therefore, the objective of this paper is to perform different studies, in terms of the stiffness response, modal analysis and steady-state response of single-walled carbon nanotubes by using a 3D finite-element model of the single-walled carbon nanotube, under different types of boundary conditions, to provide more results in this field. The single-walled carbon nanotube is modeled as a space frame structure by using the Morse potential and as a thin shell model based on various shell theories. A static analysis is performed to compare the stress–strain behavior between the Morse potential and the thin shell model. A parametric study on chirality effects and aspect ratio is also conducted to determine which shell theory is more suitable to model the mechanical behavior of single-walled carbon nanotubes. Finally, the analysis of harmonic response is conducted to describe the steady-state response between both the models.

Optimum design and failure prevention against diverse degradation mechanisms of reactor vessel internals(RVIs) are one of safety concerns in nuclear industries. The present study is to investigate effectiveness of current evaluation procedure of the RVIs under pump pulsating conditions as a part of comprehensive vibration assessment program. At first, pressure propagation analyses were performed subjected to typical steady-state and transient conditions to generate pulsating pressure distributions. Subsequently, modal analyses were conducted to examine effect of coolant modeling on dynamic characteristics. Harmonic response analyses were also carried out to examine effect of integrated assembly and numerical analyses data were compared each other and with limited measured data. As a result, it was proven that the integrated assembly with the coolant modeling could predict further realistic behaviors of RVIs instead of the current sub-component models adopting equivalent added-mass assumption.

Calculating the first and second derivatives of Power Spectrum Density (PSD) function with respect to various design variables is a prerequisite for random responses when gradient-based algorithms are adopted. This paper presented two numerical methods to capture the sensitivity and Hessian matrix of the PSD function for non-classically damped systems subject to stationary stochastic excitations. The direct differentiate method (DDM) is adopted to develop the design sensitivity analysis (DSA). By using Pseudo-Excitation Method (PEM), the governing equations of the non-classically damped system subject to stationary stochastic excitations are transformed into a corresponding deterministic harmonic response problem. Then, the first and second derivatives of the PSD function are given in detail using the DDM. Two numerical methods, namely PEM-modal displacement method (MDM) and PEM-hybrid expansion method (HEM), are proposed to compute the sensitivity and Hessian matrix of the PSD function. The computational accuracy and efficiency of both methods are discussed and compared theoretically and numerically by two illustrations. The results indicate that both methods are valid for the DSA of the PSD function for non-classically damped systems and the PEM-HEM is more suitable than the PEM-MDM with all computational considerations.

Adhesive bonding is increasingly used in automobile, marine and aeronautical structures. The dynamic response of adhesively bonded joints is therefore a main concern. This paper deals with the harmonic response of single-lap joints. A closed-form analytical solution is derived to account for the case of joints with dissimilar substrates. The transfer functions predicted by the analytical model match well the transfer functions predicted by a two-dimensional finite element analysis, and so do the natural frequencies. The numerical and analytical models show that the natural frequencies are sensitive to the order of substrates. Mainly, fixing the end of the stiffer substrate leads to natural frequencies that are mostly higher than those which are obtained by fixing the end of the softer substrate.

Screening is an indispensable unit process for separation of materials. Large vibrating screen is extensively used in coal processing because of its large production capacity. In this study, a novel large vibrating screen with duplex statically indeterminate mesh beam structure (VSDSIMBS) was presented. The dynamic model of VSDSIMBS was proposed, and characteristic parameters were obtained by theoretical calculations. In order to obtain more reliable and believable research results, model of a traditional vibrating screen (TVS) with the same mass was also established for comparisons with VSDSIMBS. The finite element (FE) method was applied to study the performance of VSDSIMBS and FE analysis of VSDSIMBS and TVS was completed by using characteristic parameters. Modal analysis results indicated that VSDSIMBS could avoid the resonance and run more smoothly than TVS. Furthermore, harmonic response analysis results showed that VSDSIMBS could improve the entire stress distribution, reduce high stress areas, and increase the strength of vibrating screen. With DSIMBS, the maximum stress of vibrating screen decreased from 130.53 to 64.54 MPa. The full-scale experimental tests were performed to validate the credibility and accuracy of FE analysis results. The stress and displacements of VSDSIMBS were measured under working conditions. The test results obtained are in good agreement with simulation results, and accord with conclusions made from FE analysis.

In the present paper, the design and optimization of a high frequency excitation source is presented. The device was developed for a harmonic response analysis test bench, aimed at dynamic characterization and resonance prediction of mechanical structures. A wide frequency range must be covered, depending on the analyzed structure: the range 1–10 kHz was considered in the present work. The device was designed for a test bench aimed at investigating the vibrational response of centrifugal compressor bladed wheels. A really compact solution was needed since the final test bench provides one exciter for each blade (up to 20 devices on the circumference hoop). Both contact and contactless solutions were considered, but only the contact solution was found to fulfill all the specifications. Finally, different stinger solutions were proposed and compared in the paper. The investigated solutions were: a beam stinger (diameter 1 mm); a wire stinger (diameter 0.2 mm); and a ball stinger (diameter 3 mm) with two different support solutions. Experimental tests performed on a device prototype allowed to verify the specifications fulfillment and to choose the best stinger solution for the application.

This paper proposes a model updating strategy for localised nonlinear structures. It utilises an initial finite-element (FE) model of the structure and primary harmonic response data taken from low and high amplitude excitations. The underlying linear part of the FE model is first updated using low-amplitude test data with established techniques. Then, using this linear FE model, the nonlinear elements are localised, characterised, and quantified with primary harmonic response data measured under stepped-sine or swept-sine excitations. Finally, the resulting model is validated by comparing the analytical predictions with both the measured responses used in the updating and with additional test data. The proposed strategy is applied to a clamped beam with a nonlinear mechanism and good agreements between the analytical predictions and measured responses are achieved. Discussions on issues of damping estimation and dealing with data from amplitude-varying force input in the updating process are also provided.

This paper deals with the estimation of forcing functions on a mistuned bladed rotor from measurements of harmonic response via Kalman Filter in time domain. An unique feature of this approach is that the number of estimated variables can be far greater than the number of measurements. The robustness of this method to measurement errors is shown. It is also shown that direct prediction of amplitude and phase of sinusoidal force vector from input/output frequency response function has a large amount of errors in the presence of unavoidable measurement noise. Numerical examples contain both frequency mistuning and geometric mistuning.Copyright © 2017 by ASME

This paper is aimed at eliminating the influence of the problem of the harmonic response analysis of non-classically damped systems with lower-higher-modal truncation. Based on the Neumann expansion theorem and the frequency shifting technique, the relationships satisfied by eigensolutions and system matrices are established and an explicit expression on the lower-higher-modal truncation error of harmonic responses can be expressed as a sum of available modes and system matrices. A correction method, which only involves the available modes and system matrices, is then presented to calculate the harmonic responses. The method maintains original-space without having to involve the state-space equation of motion such that it is efficient in computational effort and storage capacity. The method is convergent if and only if all the modes whose resonant frequencies lie within the range of excitation frequencies are available. Finally, a two-stage floating raft isolation system and a sandwich plate are used to to validate the effectiveness of the presented method.

The research object is hydraulic tool turret cabinet of CNC lathe. Building the hydraulic tool turret cabinet model by Pro/E, then meshing the cabinet by Hyper-mesh software, finally calculating by the ANSYS. Do modal analysis and harmonic response analysis for the cabinet, then make the second order frequency maximum as a target, use the Altair OptiStruct to improve its dynamic structure. The result shows: though the quality of optimized body is increased, but it avoids the resonance frequency, which greatly reduce the possibility of resonance, and greatly improve the dynamic performance of the cabinet.

An efficient iterative method, which only requires normal modes, is presented to calculate the harmonic response of viscoelastic structures. The method only needs to iteratively solve a diagonal dynamic equation instead of solving the dynamic equation directly such that it takes O(N^2) instead of O(N^3). However, the iterative procedure based on lower normal modes cannot be converged to the exact result. A modal correction technique is therefore introduced to improve the accuracy of iterative results. Finally, the efficiency and applicability of the method are illustrated in terms of sandwich plates with different types of viscoelastic core.

To model damping effects in structural dynamics, the literature provides a wide range of alternatives. The different models claim different advantages and fields of use where they are useful but, in the end, the compliance of the model with the experimental results, within a given tolerance, is the ultimate criterion for assessing its quality. In the present paper, the behaviour of a simple steel specimen is studied, taking as a focus the time response of the material. Since the harmonic response is well established, the authors propose to submit the specimen to a trapezoidal periodic load and study the behaviour of the response to the load changes. A simple setup was used, using a steel specimen loaded in the linear regime. A carefull test procedure was carried out in order to characterize the dissipation in a quasi-static periodic load. The experimental results show that the response delay to a ramp load depends on the durations of both the previous flat and the ramp itself.

Optical path length variations due to temperature, manufacturing misalignments, operation environments can affect the performance of ring laser gyroscope (RLG). This paper presents a structural design of optical path length control device (PLC) using finite element analysis. The static analysis and harmonic response analysis of the PLC is performed to investigate the deformation on different voltage, and model analysis is selected to determine the natural frequency and eigenmodes. To validate the simulation results, an experiment on RLG with mode-scanning is carried out and the maximum errors are within 0.025um. The experiment results are found to be in good agreement with the simulation results. The results indicate that the finite element model can be beneficial to designing and optimizing the structural parameters for the PLC.

With energy consumption and the development of exploitation technology of oil and gas underground, the drilling engineering has developed toward the direction of deep well, even ultra-deep well. The problem of fatigue of drill string has a great effect to drilling engineering. Strong vibration is one of the main reasons that induce drill string fatigue. In this study drill string of deep well is object being studied. The models about longitudinal vibration is set up. First, modal vibrations of drill string are studied. Then, harmonic response analysis of drill string vibration is studied. Rules of all kinds of free frequency are obtained by drilling instance. This study can offer basic method for optimizing drilling tool of deep well and drilling parameter for the purpose of reducing drill string failure.

On the basis of the Mechanics and Kinematics analysis of built-in chatter suppression boring bar, the research analyzes the motional stability of built-in chatter suppression boring bar, and uses SIMS vibration absorbers for chatter suppression theory to design the characteristic parameters of vibration absorber; then with MATLAB optimized to get structural material parameters of vibration absorber; finally conduct harmonic response analysis to built two-dimensional model of built-in chatter suppression boring bar by ANSYS, compare and optimize the results to guide the development of built-in chatter suppression boring bar.

Vibration-based structural damage detection has been the focus of attention by many researchers over the last few decades. However, most methods proposed for this purpose utilize extracted modal parameters or some indices constructed on the basis these parameters. Our literature review revealed that few papers have employed frequency response functions (FRFs) for detecting structural damage. In this paper, a technique is presented for damage detection which is based on measured FRFs. Independent component analysis (ICA) has been implemented on the spatiotemporal responses in each frequency in order to reduce the dimension of the data. This is based on the concept that the forced harmonic response of a linear vibrating system can be fully captured utilizing a single ICA mode. A different approach is also presented in which ICA is applied to the frequency domain data. Operational deflection shapes (ODSs) have been decomposed using ICA to localize the damage. The efficiency of both methods is demonstrated through some numerical and experimental case studies.

It is essential to investigate the vibration properties of piping system in air conditioner. Finite Element Method is used to build the virtual prototype model of the air conditioner, and the dynamic responding analysis was conducted using ANSYS software. The modal analysis and harmonic response analysis was conducted for different modals and the results was compared. The simulation results showed that the vibration characteristics of modified model is better than that of the original model, thus resonance phenomenon could be avoided.

This paper elaborated the practical application of NC Planer Drilling Machine and the important consequence of main shaft structure to working qualities and working accuracy. Then it introduced the design proposal for the spindle structure of drilling machine. The static analysis, modal analysis and harmonic response analysis were done by using ANSYS. It lays a foundation for optimal design and remanufacturing.

Purpose, with the application of workbench finite element analysis software, get the analysis results of DVG 850 high-speed vertical machining center via the modal analysis and harmonic response analysis. Use the calculation results for reference, put forward the improved method, and prove the credibility of the simulation analysis by testing DVG 850 prototype.

With the five-axis grinding machine tool bed as the research object, the maximum deformation region can be found after analyzing the static characteristics in the use of the grinder limit positions. Through free modal analysis and constraint modal analysis, the vibration characteristics of each order of the bed can be seen and a point in the maximum deformation region is selected to carry out the harmonic response analysis to predict the sustainable dynamic characteristic. According to the results of analysis, find out the weak areas in the bed and conduct the weight-lowing optimization on the condition of no reduction of static and dynamic characteristic of the bed. This paper draws the conclusion of reduction of weight of 143.42kg and materials of 7.73%.

This paper provides the methodology on analyzing the dynamic characteristic of machine tool in consideration of joint parameters. To ensure the dynamic model is available for further study, modal experiment for vertical machining center is involved. The machine tool is divided into several parts and connected with spring and damping for substructure modeling. Particularly, the bolt-fixed joint is an example for the joints modeling. Based on the dynamic model, simulation of modal analysis and harmonic response are carried out. Besides, method of optimization design of column and milling box is given to improve the performance, which is proved to be feasible in harmonic response.

The virtual prototype is a computer simulation model of the physical product that can be analyzed like a real machine. This paper studies the helical milling unit based on the virtual machine tool. The helical milling unit is first designed according to the kinematics of the helical milling. The main parts of the equipment include rotating mechanism, orbital agency and radial offset organization. Based on the feasibility analysis of the structure, the three-dimensional geometrical model is built in the Solidworks software. The key parts in the model are separated from the device and introduced into the finite element analysis (FEA) software, according to the cutting loads tested from experiment, static and dynamic modal analysis and harmonic response analysis are carried out for the key parts of this device. The results show that the static and dynamic stiffness can meet design requirement.

The role of thermal mass is very important in natural ventilated buildings. Thermal mass can be classified as external thermal mass and internal thermal mass. In this paper, a heat balance model for naturally ventilated building is developed. The effect of external thermal mass is introduced by harmonic response method, and the effect of internal thermal mass is calculated by virtual sphere method which can lump different shapes and types into one virtual sphere. The effective convection heat transfer coefficient is presented to represents the effect of uneven distribution of internal thermal mass temperature. Through comparison with Li's model [1] and numerical calculation, it was found that the model is more suitable than the others, especially in estimating decrement factor of indoor air temperature. The errors of time lag become smaller when the fluctuation of indoor air temperature is smaller. Based on the model, a simple tool is developed to evaluate the indoor air temperature and required internal thermal mass for certain naturally ventilated buildings.

This paper focuses on the structural optimization of chemical sensor support for food safety detection. The mechanical characteristic of chemical sensor support is influenced greatly by its structural parameters. Aiming at improving dynamic stiffness of the support, the modal analysis is implemented with the dynamic theory and the finite element analysis. And a group of rational structure parameters are determined through the optimum calculation. The validity simulation of the optimization is verified by the analyses of the random vibration and harmonic response. The results demonstrate that the performance of the support of the chemical sensor applied for the food detection is enhanced greatly by the presented optimization method here.

Modal analysis of machine center was carried out by means of finite-element analysis (FEA) method to get its characteristics and to improve its machining precision. Based on this, harmonic response analysis was processed to evaluate its vibration when the cycle load caused by the machining force was applied on the main shaft of machine center, which was used to provide clues for avoiding resonance vibration and ameliorating design.

The different-speed mixer is used in the rubber industry widely. The dynamic response of different-speed mixer shaft is very key. Some displacement and dynamic stress response values of different-speed mixer shaft frequency are obtained by using the finite element method, which gives the basic theory for further systematic dynamic analysis and the structure design of different-speed mixer shaft.

The performance of spindle system of machine tools directly affects the characters of machine tools. The static and dynamic stiffness of spindle system is one of the main factors that affect the machining precision of machine tools and the performance analysis of spindle system occupies an important position in the design of machine tools. Based on ANSYS, this paper analyzed static stiffness, vibration characters and harmonic response of spindle system of SSCK63-400-typed CNC lathe. Selecting improving the characters and saving the cost of spindle as optimization object and using APDL of ANSYS, the optimization of the spindle is completed by the optimization tools of ANSYS. This research provided the basis for statics and dynamics design of spindle system, shortened the design period and improved the design efficiency.

In this paper, we presented the results from three related analysis performed by adopting the failure models, which provided an explanation of performance influencing factors caused by different number of contact cores, for the purpose of measuring the temperature change and deformation value, which were the factors causing contact failure. The failures were localized in contact parts of the connectors. Performed investigations included thermal analysis, modal analysis, harmonic response analysis and contact failure analysis. From the results of these simulations, related temperature and vibration analysis nephograms were got respectively. And the correctness of results of thermal analysis was verified by Fourier law. The research results of this paper provide a reference for thermal analysis and vibration analysis of electrical connectors, which is important for ensuring the reliability and safety of electrical connectors.

Orhan, Sadettin/0000-0002-9751-6665 WOS: 000248243100004 Structures are weakened by cracks. When the crack size increases in course of time, the structure becomes weaker than its previous condition. Finally, the structure may breakdown due to a minute crack. Therefore, crack detection and classification is a very important issue. In this study, free and forced vibration analysis of a cracked beam were performed in order to identify the crack in a cantilever beam. Single- and two-edge cracks were evaluated. The study results suggest that free vibration analysis provides suitable information for the detection of single and two cracks, whereas forced vibration can detect only the single crack condition. However, dynamic response of the forced vibration better describes changes in crack depth and location than the free vibration in which the difference between natural frequencies corresponding to a change in crack depth and location only is a minor effect. (c) 2007 Elsevier Ltd. All rights reserved.

To minimize the leakage of microwave which can occur when one pulls the door of a microwave oven during its operation, shape optimization of the door frame is presented. A numerical optimization is implemented to minimize the dynamic twisting deformation of the door frame. Shape design variables are defined, which represent the dimension of the bead in the flange. Two optimal design problems are established to minimize the maximum twisting deformation from harmonic response analysis. The problems are solved, their results being compared and evaluated.

We report on a new method for characterising crystallinity and polymorphism of pharmaceutical drugs and excipients in the solid state. The optical nonlinearity of certain crystalline structures allows under certain circumstances the quantitative determination of polymorphism or crystallinity. An apparatus was set up to measure the second harmonic response of powdered samples when irradiated with a pulsed laser source. Here we present experimental results from various pharmaceutically interesting materials. This rapid, novel technique has potential for industrial monitoring of pharmaceutical manufacturing processes.

Remotely Operated Vehicle of 6000-meters is a new conceptual equipment made to replace the manned systems for investigating the deep-sea environment, and all of the ROV systems in operational condition strongly depend on the connecting cables. In this point of view dynamics of the ROV cable system is very important for operational and safety aspects as a cable generally encounters great tension. Researches have been executed on this problem, and most of papers have been mainly focused on the operational condition of ROV system in deep sea. This paper presents the dynamic cable response analysis during ROV launching condition rather than the operational one in order to provide the design guide of a ROV cable system in this circumstance, considering the coupling effects between cable and wave-induced ship motion. To obtain the variations of cable tensions during a ROV launching, a pre-stressed harmonic response analysis was carried out. Wave-induced tensions of the cable during ROV launching were obtained in real sea states using FE modeling, and the basic design guide of a ROV cable system was obtained.

In this paper, a two-point boundary value problem for an integrodifferential equation is studied. This equation describes the dynamics of an inclined stretched string suspended between a fixed support and a vibrating support. Due to the inclination, the string will vibrate under combined parametrical and transversal excitation. The attention will be focused on time-periodic solutions consisting of one mode (semi-trivial solution) generated by transverse (external) excitation and two modes (non-trivial solution) generated by combined parametrical and transverse excitation.

The paper deals with the problem of absorbing the harmonic response at a prescribed location in an axially vibrating rod. An explicit formula for the feedback control gain is given. A necessary and sufficient condition for allowing the control to be carried out by a passive element is determined, and the stability of the system is analysed. Examples demonstrating the various results are presented.

The modal synthesis method is frequently used for the analysis of large structures composed of multiple parts concerning dynamic aspects. In this paper, we extended the modal synthesis method under the isogeometric analysis framework. The isogeometric Kirchhoff–Love shell elements are used for the analysis of the substructures, the Craig–Bampton method is used for the modal synthesis and the bending-strip method is used for the substructures coupling. We give examples on the modal analysis and the harmonic response analysis. The results show the effectiveness of the method.

Resume La methode de la raideur dynamique egalement denommee “methode des elements continus” est un outil efficace pour l'etude de la reponse des structures a une sollicitation harmonique. Quelques codes de calcul bases sur cette formulation ont permis de developper l'utilisation “industrielle” de cette methode mais son champ d'application reste limite, pour l'essentiel, aux assemblages de poutres. Le developpement d'elements continus de type plaque est engage depuis quelques annees mais l'utilisation effective de ce type d'elements pour la modelisation de structures tridimensionnelles passe par une formulation complete de ces elements, c'est a dire relative a l'ensemble de leurs degres de libertes. L'assemblage de ces elements selon les trois dimensions de l'espace sera alors possible. L'objet de cet article est de completer les travaux concernant la flexion en presentant la demarche permettant d'etablir la matrice de raideur dynamique relative aux mouvements dans le plan d'une plaque rectangulaire. Un cas particulier de conditions aux limites est presente de maniere a illustrer la demarche, d'autres types de conditions aux limites sont traites de la meme facon. Le cas de la plaque libre pourra ensuite etre envisage comme superposition de ces cas elementaires.

The feasibility of calculating the narrow band harmonic response of thin plates and beams by using the method of images or the ray tracing technique is examined. The fundamental solution of an infinite plate is employed, in conjunction with appropriately placed images, to obtain the dynamic compliance spectra of simply supported rectangular plates over a wide range of frequencies. Predictions yielded by the method of images are in excellent agreement with the normal mode expansion technique. Simply supported beams are analyzed first by considering the fundamental solution of an infinite beam, and second as a case of a narrow plate with simply supported and roller boundary conditions. Both approaches match well with the closed form solutions and with measurements conducted on two beams. Several issues including convergence characteristics and high frequency behavior are discussed.

The case of two basemats excited by incident SH-waves is considered. The dynamic-stiffness coefficients of surface foundations on a randomly inhomogeneous layered medium, based on the stiffness matrix approach, are calculated. The solution for the harmonic response of the coupled system of basemats on a layered viscoelastic half-space is obtained.

Although there are several techniques available for the harmonic vibration analysis of non-linear systems, the application of these methods to multi-degree of freedom systems is rather limited. In this study a new method (the Iterative Receptance Method—IRM) is developed for the harmonic vibration analysis of non-linear multi-degree of freedom systems with non-linear stiffness and damping forces. Different kinds of non-linearities are covered by expressing non-linear spring and damping forces as polynomials in displacements and velocities, respectively. Quasilinear receptance matrix of a non-linear system for a given level of external forcing is determined by using the receptance matrix of the linear part of the system and a matrix representing the non-linearity in the system. An iterative algorithm is employed in the numerical solution. The iterative receptance method is also modified for an efficient dynamic analysis of structures with local non-linearities. The application of the method is demonstrated by numerical examples, and the results are found to be quite encouraging for the application of the method to practical structures with large degrees of freedom.

Magneto-electro-elastic (MEE) materials show a significant coupling between the mechanical, electrical, and magnetic fields. A three-phase MEE composite consisting of piezoelectric and piezomagnetic phases separated by a polymer matrix would have greater ductility and formability. In this article, harmonic response of three-phase MEE beam under mechanical, electrical, and magnetic load is presented using finite element method. Numerical studies are presented for different volume fraction (vf) of the magnetic phase in the three-phase MEE composite. Studies are done for clamped-free boundary condition of the beam. Ansys 8.1 is used to validate the code developed. The influence of various coupling term is also studied. The effect of coupling terms influencing the load vector plays a major role in the generation electric and magnetic potential when subjected to magnetic and electric conditions. � 2009 SAGE Publications.

In the paper, the characteristics of mode and harmonic response of the axis of the high-speed motorized spindle are presented with the FEM (Finite Element Method). A dual-dimension model with the FEM is developed and simulated using ANSYS commercial software. The result shows that the rated rotating speed of the high-speed motorized spindle is far smaller than the first-order natural resonance speed, and the dynamic displacement and stiffness do not change significantly compared with the static performance of working of the motorized spindle. The dynamic characteristics of the motorized spindle are accord with the requirements of design.

The growth-strain method, developed using the finite-element calculation of the deforming of shapes produced by swelling and contracting of itself, was previously proposed as a shape optimization method. The present report describes an application of the growth-strain method to the problems of steady-state vibration. In particular, free vibration with a normal mode and vibrational response to a harmonic excitation are considered. A difference of the implementation of the method for these vibration problems from that for static problems lies in analyzing the stress distribution at the deformation in the normal mode or in the amplitude of the vibrational response. Numerical examinations are carried out on simple beam structures. In these examinations, the growth-strain method shows a feasibility even in the optimization of structures under dynamic circumstances., ・rights：日本機械学会・rights：本文データは学協会の許諾に基づきCiNiiから複製したものである・relation：isVersionOf：http://ci.nii.ac.jp/naid/110002503190/