Shock and Vibration

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

List of Papers (Total 159)

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...

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...

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...

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...

A Systematic Approach to Identify Sources of Abnormal Interior Noise for a High-Speed Train

A systematic approach to identify sources of abnormal interior noise occurring in a high-speed train is presented and applied in this paper to resolve a particular noise issue. This approach is developed based on a number of previous dealings with similar noise problems. The particular noise issue occurs in a Chinese high-speed train. It is measured that there is a difference of...

Soil-Structure Interaction Effect on Fragility Curve of 3D Models of Concrete Moment-Resisting Buildings

This paper presents the probabilistic generation of collapse fragility curves for evaluating the performance of 3D, reinforced concrete (RC) moment-resisting building models, considering soil-structure interaction (SSI) by concentration on seismic uncertainties. It considers collapse as the loss of lateral load-resisting capacity of the building structures due to severe ground...

Deformation Control in Rest-to-Rest Motion of Mechanisms with Flexible Links

This paper develops and validates experimentally a feedback strategy for the reduction of the link deformations in rest-to-rest motion of mechanisms with flexible links, named Delayed Reference Control (DRC). The technique takes advantage of the inertial coupling between rigid-body motion and elastic motion to control the undesired link deformations by shifting in time the...

Simulation Analysis of a Multiple-Vehicle, High-Speed Train Collision Using a Simplified Model

To solve the problems associated with multiple-vehicle simulations of railway vehicles including large scale modelling, long computing time, low analysis efficiency, need for high performance computing, and large storage space, the middle part of the train where no plastic deformation occurs in the vehicle body was simplified using mass and beam elements. Comparative analysis of...

Adaptive Reconstruction of a Dynamic Force Using Multiscale Wavelet Shape Functions

The shape function-based method is one of the very promising time-domain methods for dynamic force reconstruction, because it can significantly reduce the number of unknowns and shorten the reconstruction time. However, it is challenging to determine the optimum time unit length that can balance the tradeoff between reconstruction accuracy and efficiency in advance. To address...

Modeling, Testing, and Characteristic Analysis of a Planetary Flywheel Inerter

We propose the planetary flywheel inerter, which is a new type of ball screw inerter. A planetary flywheel consists of several planetary gears mounted on a flywheel bracket. When the flywheel bracket is driven by a screw and rotating, each planetary gear meshing with an outer ring gear generates a compound motion composed of revolution and rotation. Theoretical analysis shows...

The Maximum Height and Attenuation of Impulse Waves Generated by Subaerial Landslides

High-speed landslides that flow into reservoirs can cause impulsive water waves. To study the characteristics of the maximum impulse wave’s height and its attenuation, 25 sets of flume experiments were conducted using orthogonal theory and 6 main influencing factors were considered. Taking the impulse wave heights as the evaluation criteria and analyzing the 6 influencing factors...

Heteroclinic Bifurcation Behaviors of a Duffing Oscillator with Delayed Feedback

The heteroclinic bifurcation and chaos of a Duffing oscillator with forcing excitation under both delayed displacement feedback and delayed velocity feedback are studied by Melnikov method. The Melnikov function is analytically established to detect the necessary conditions for generating chaos. Through the analysis of the analytical necessary conditions, we find that the...

Review of Blast Loading Models, Masonry Response, and Mitigation

Different models for prediction of blast loading, response of masonry structure against blast load, and various mitigation strategies are discussed. Variation of peak positive incident pressure with scale distance in free field spherical burst and surface burst scenarios, proposed by different researchers, is presented and compared. The variation is found significant in the...

Experimental Investigation and Analysis of Dynamic Buckling of Drill String in Horizontal Well

Buckling of tubulars has been the subject of many researches in the past. However, the models in previous research always followed the same assumptions: the friction and rotation effects are ignored. The assumptions are relatively far from the reality. This paper focuses on the rotational drill string in horizontal well. The differential equation of the dynamic buckling is...

Numerical Studies of Propeller Exciting Bearing Forces under Nonuniform Ship’s Nominal Wake and the Influence of Cross Flows

Propeller exciting forces are the main causes of stern vibrations. In this paper, three-dimension exciting bearing forces of one blade and the whole propeller under nonuniform ship’s wake were predicted, and the influence of cross flows on these exciting forces was studied. All simulations were carried out using a commercial solver, STAR-CCM

Analysis on Multistable Motion Characteristics of Supercavitating Vehicle

Due to complex underwater environment, when the initial condition of launching is subjected to low external disturbance, the motion trace of a supercavitating vehicle might display many different motion states during underwater navigation. With the aim of addressing this problem, based on the dynamic map, in the present work the multistable phenomena of attractor coexistence of...

Impact Dynamics of a Percussive System Based on Rotary-Percussive Ultrasonic Drill

This paper presents an impact dynamic analysis of a percussive system based on rotary-percussive ultrasonic drill (RPUD). The RPUD employs vibrations on two sides of one single piezoelectric stack to achieve rotary-percussive motion, which improves drilling efficiency. The RPUD’s percussive system is composed of a percussive horn, a free mass, and a drill tool. The percussive...

The Parameters Optimizing Design of Double Suspension Arm Torsion Bar in the Electric Sight-Seeing Car by Random Vibration Analyzing Method

This study is about the impact of the performance and the sensitivity analysis for parameters of the torsion bar suspension in the electric sight-seeing car, which the authors’ laboratory designed and which is used in the authors’ university. The suspension stiffness was calculated by using the virtual work principle, the vector algebra, and tensor of finite rotation methods and...

Numerical Simulation and Experimental Study on the Gas-Solid Coupling of the Aerostatic Thrust Bearing with Elastic Equalizing Pressure Groove

Aiming at the problem of low stiffness of aerostatic bearing, according to the principle of gas-solid coupling, this paper designs a kind of aerostatic thrust bearing with elastic equalizing pressure groove (EEPG) and investigates the effect of elastic equalizing pressure groove (EEPG) on the stiffness of aerostatic bearing. According to the physical model of the bearing, one...

Numerical Analysis on Steam Exciting Force Caused by Rotor Eccentricity

The steam exciting force has been proved to be great threat to the operation safety of steam turbines. The mechanism of steam exciting vibration cannot be profoundly revealed by simply analyzing the steam exciting force, especially in simplified models. Therefore, a full-circle stage of steam turbine with shroud and labyrinth seals was investigated by numerical simulator CFX. The...

Gust Wind Effects on Stability and Ride Quality of Actively Controlled Maglev Guideway Systems

The purpose of this paper is to present a framework to analyze the interaction between an actively controlled magnetic levitation vehicle and a guideway structure under gusty wind. The equation of motion is presented for a 30-dof maglev vehicle model consisting of one cabin and four bogies. In addition, a lateral electromagnetic suspension (EMS) system is introduced to improve...

Integration of Geometrical and Material Nonlinear Energy Sink with Piezoelectric Material Energy Harvester

This paper presents a novel design by integrating geometrical and material nonlinear energy sink (NES) with a piezoelectric-based vibration energy harvester under shock excitation, which can realize vibration control and energy harvesting. The nonlinear spring and hysteresis behavior of the NES could reflect geometrical and material nonlinearity, respectively. Two configurations...

Damage Analysis of Aluminium Foam Panel Subjected to Underwater Shock Loading

Underwater shock loading experiment device is the equipment which simulates underwater explosive shock wave through experiment. Underwater shock loading experiment device was used to conduct high-speed underwater impact on aluminium foam panel and its damage modes were studied in this paper. 3D dynamic DIC test system was used to collect and analyze real-time deformation of...

Modified Kernel Marginal Fisher Analysis for Feature Extraction and Its Application to Bearing Fault Diagnosis

The high-dimensional features of defective bearings usually include redundant and irrelevant information, which will degrade the diagnosis performance. Thus, it is critical to extract the sensitive low-dimensional characteristics for improving diagnosis performance. This paper proposes modified kernel marginal Fisher analysis (MKMFA) for feature extraction with dimensionality...