Shock and Vibration

https://www.hindawi.com/journals/sv/

List of Papers (Total 989)

Blast Induced Crack Propagation and Damage Accumulation in Rock Mass Containing Initial Damage

Blast induced rock mass damage and crack propagation play important roles in structure safety and stability in mining, quarrying, and civil constructions. This paper focuses on the effect of small blasthole diameter blast on crack propagation and damage accumulation in water-bearing rock mass containing initial damage composed of inherent geological discontinuities and previous...

Temperature Effects on Nonlinear Vibration Behaviors of Euler-Bernoulli Beams with Different Boundary Conditions

This paper is concerned with temperature effects on the modeling and vibration characteristics of Euler-Bernoulli beams with symmetric and nonsymmetric boundary conditions. It is assumed that in the considered model the temperature increases/decreases instantly, and the temperature variation is uniformly distributed along the length and the cross-section. By using the extended...

An Experimental Investigation on the Relationship between MS Frequency Response and Coal and Gas Outburst

Microseismic (MS) frequency response is an important part of high-efficiency data mining to achieve the aim of coal and gas outburst (CGOB) early warning. Based on the variation pattern of acoustic emission (AE) signal in the coal failure process, the experimental characteristics of MS activity and typical signals CGOB were obtained in this study. First, the AE behavior of coal...

An Experimental Investigation on the Relationship between MS Frequency Response and Coal and Gas Outburst

Microseismic (MS) frequency response is an important part of high-efficiency data mining to achieve the aim of coal and gas outburst (CGOB) early warning. Based on the variation pattern of acoustic emission (AE) signal in the coal failure process, the experimental characteristics of MS activity and typical signals CGOB were obtained in this study. First, the AE behavior of coal...

Study on Vibrational Power Flow Propagation Characteristics in a Laminated Composite Cylindrical Shell Filled with Fluid

The characteristics of vibrational power flow in an infinite laminated composite cylindrical shell filled with fluid excited by a circumferential line cosine harmonic force are investigated using wave propagation approach. The harmonic motions of the shell and the fluid filled in the shell are described by Love shell theory and acoustic wave equation, respectively. Under the...

Proposal of a Viscous Model for Nonviscously Damped Beams Based on Fractional Derivatives

Viscoelastic materials are widely used in structural dynamics for the control of the vibrations and energy dissipation. They are characterized by damping forces that depend on the history of the velocity response via hereditary functions involved in convolution integrals, leading to a frequency-dependent damping matrix. In this paper, one-dimensional beam structures with...

Inelastic Parametric Analysis of Seismic Responses of Multistorey Bidirectional Eccentric Structure

This paper conducts a parametric study on the seismic response of multistorey bidirectional eccentric structures from elastic stage to inelastic stage. Based on a simplified multistorey bidirectional eccentric model composed of bidirectional lateral load-resisting members, a general law is proposed for three-stage natural frequency variation behaviour from elastic stage to...

Nonlinear Random Response Analyses of Panels Considering Transverse Shear Deformations under Combined Thermal and Acoustic Loads

The panel structures of flight vehicles at supersonic or hypersonic speeds are subjected to combined thermal, acoustic, and aerodynamic loads. Because of the combined thermal and acoustic loads, the panel structure may exhibit nonlinear random vibration responses, such as the snap-through phenomenon and random vibrations. These unique dynamic behaviors of the panel structure...

Reaction Force Compensator for High-Speed Precision Stage of Laser Direct Imaging Process

Recently, laser direct imaging (LDI) process has become popular as a substitute for lithography in flexible printed circuit board (FPCB) manufacturing industry. However, repeated motion of the process equipment causes residual vibration in a transient state when the stage accelerates or decelerates. The supporting structure for the laser head is complex and heavy in order to...

Analysis of Vibration Reduction by Damping Using Simple Analytical Modelling

The performance of different solutions to global vibration reduction using external damping is discussed. The solutions are either uneven distribution of structural damping or use of vibration absorbers. To this end, a comparative study is carried out, built on simple analytical models. It is shown that a well-chosen solution can produce a substantial reduction of global...

Finite Particle Method-Based Collapse Simulation of Space Steel Frame Subjected to Earthquake Excitation

In the process of collapse failure of the space steel frame subjected to earthquake excitation, complex behaviors often are involved, including geometric nonlinearity, material nonlinearity, fracture, contact, and collisions. In view of the unique advantages of the finite particle method to analyze complex structural nonlinear problems, this paper utilized the finite particle...

Oblique Incidence of Seismic Wave Reflecting Two Components of Design Ground Motion

The wave field on the artificial boundary was separated into the free field without local topography effect and scattering field induced by local topography effect. The simulation of the free field under obliquely incident waves was conducted. Based on the assumption that the components of design ground motion were treated as the coincidence of oblique P wave and oblique SV wave...

Online Structural Health Monitoring of Rotating Machinery via Ultrasonic Guided Waves

This paper focuses on the establishment of the online structural health monitoring strategy for rotating shafts using ultrasonic guided waves. The dispersion of cylindrical shaft is investigated and a conclusion that the longitudinal ultrasonic wave propagating along the cylindrical shaft can hardly be interfered by the rotation is obtained. The experimental system and the...

Transmission Error Analysis and Disturbance Optimization of Two-Stage Spur Gear Space Driven Mechanism with Large Inertia Load

For the nonlinear disturbance actual issues of the model space drive mechanism two-stage spur gear system, a nonlinear dynamic model of 14-DOF (degree of freedom) two-stage spur gear with time-varying stiffness and damping was established. This model has been developed previously by the authors to access the large inertia on the dynamic response of spur gear space driving...

Oblique Incidence of Seismic Wave Reflecting Two Components of Design Ground Motion

The wave field on the artificial boundary was separated into the free field without local topography effect and scattering field induced by local topography effect. The simulation of the free field under obliquely incident waves was conducted. Based on the assumption that the components of design ground motion were treated as the coincidence of oblique P wave and oblique SV wave...

Quasi-Static Cyclic Test on a Concrete-Encased Frame-Reinforced Concrete Tube Building Model

This paper experimentally investigated the seismic behavior of a 1:5 reduced-scale model of concrete-encased steel frame-reinforced concrete core tube building. The quasi-static testing with multipoint loading was carried out, and mode-superposition response spectrum method was adopted to control the amplitude of displacement. The damage process, crack pattern, and failure mode...

Dynamics of a Upright Pole Coupled with Nonlinear Hysteretic Isolators under Harmonic Base Excitation

Leady isolator shows hysteretic nonlinearity. The isolation efficiency of leady isolator is an important problem in many engineering structures. In this paper, vibrations of a ceramic upright pole coupled with four leady isolators under harmonic base excitation are studied. A hysteretic force-deformation model of leady isolator is derived from experimental results. With this...

Damping Identification with Acceleration Measurements Based on Sensitivity Enhancement Method

The damping is important for forward and inverse structural dynamic analysis, and damping identification has become a hot issue in structural health monitoring recently. The dynamic responses of the structure can be measured in practice, and the structural parameter usually can be identified by inverse response sensitivity analysis. To reduce the measurement noise effect and...

Structural Damage Identification Based on the Transmissibility Function and Support Vector Machine

A novel damage identification method based on transmissibility function and support vector machine is proposed and outlined in this paper. Basically, the transmissibility function is calculated with the acceleration responses from damaged structure. Then two damage features, namely, wavelet packet energy vector and the low order principal components, are constructed by analyzing...

Supercritical Coexistence Behavior of Coupled Oscillating Planar Eccentric Rotor/Autobalancer System

The automatic balancing and undesirable nonsynchronous behavior of coupled oscillating configured flexible foundation and planar eccentric rotor equipped with a passive autobalancer (AB) system has been thoroughly investigated here. Specifically, it is described that the unified AB/rotor unit is attached to a foundation via a symmetric support and the foundation is also mounted...

Joints Parameters Identification in Numerical Modeling of Structural Dynamics

The dynamics of assembled structures are significantly dependent on joints. Joints parameters, owing to be difficultly measured, are always ignored by pure rigid in numerical modeling and it will result in unreliable or even error descriptions. 13 Hz deviations may cause resonance especially in engineering optimization issues; hence it is necessary to identify joints parameters...

The Mechanical and Fracturing of Rockburst in Tunnel and Its Acoustic Emission Characteristics

The phenomenon of acoustic emission (AE) is associated with rock failure and rock fracturing. In order to investigate the influence of tectonic stress on rockburst in tunnel, a biaxial loading experiment system was used in this study. The excavation operation is undertaken at the center of samples to monitor the tunnel forming process in situ, and the different horizontal...

MEMS Inertial Sensor for Strata Stability Monitoring in Underground Mining: An Experimental Study

To investigate the fracture and deformation characteristics of the strata in underground mining as well as the effectiveness and sensitivity of the MEMS inertial sensor for strata stability monitoring, a low cost, small size, and easy implementation inertial MEMS sensor module was redeveloped. Sensor modules were installed on roof strata in an underground mining equivalent...

Lateral-Torsional Coupling Characteristics of a Two-Stage Planetary Gear Rotor System

Planetary gears are one part of the whole transmission chain, and the dynamics and vibration characteristics of them are strongly coupled with external rotors. In this paper, to demonstrate the interaction between multistage planetary gears and external rotors as well as investigate the lateral-torsional coupling characteristics of them, a coupling model of a two-stage planetary...