Table of Contents Author Guidelines Submit a Manuscript
Shock and Vibration
Volume 2017, Article ID 2670218, 12 pages
https://doi.org/10.1155/2017/2670218
Research Article

Dynamic Characteristics Analysis of a Seismic Vibrator-Ground Coupling System

School of Mechatronic Engineering, Southwest Petroleum University, No. 8 Xindu Avenue, Xindu District, Chengdu, Sichuan 610500, China

Correspondence should be addressed to Liu Jun; moc.qq@29330899

Received 13 March 2017; Accepted 22 May 2017; Published 4 July 2017

Academic Editor: Ivo Caliò

Copyright © 2017 Liu Jun et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A mathematical model to describe the seismic vibrator and ground coupling is proposed based on dynamic analyses of the vibrator baseplate structure and properties of soil. This mathematical model is solved using Newmark’s method. It produces reasonable results and the trend of amplitude envelope follows the experimental data. With this model, characterization of the vibrator-ground coupling is performed. Modal analysis study shows that the motions between the vibrator reaction mass and baseplate experience a combination of a first-order vibration mode and a second-order vibration mode. The corresponding frequencies of two vibration modes are located at 2.77 Hz and 488.7 Hz, respectively. As the frequency goes up, the motion behavior of the reaction mass and baseplate is dominated by the second-order vibration mode. It is realized that the second-order vibration mode is responsible for the phase difference between the input sweep signal and the output force signal. Furthermore, the impact of the coupling system parameters on the vibrator output force is also investigated. It is observed that the vibrator output force decreases as the sweep frequency increases. The weight ratio of the reaction mass and the baseplate has an impact on the vibrator output force.