scholarly journals The Influence Law of Multi-point Cumulative Blasting in Slope

2021 ◽  
Vol 14 ◽  
pp. 1074-1088
Author(s):  
Liu Han ◽  
Jisen Shu ◽  
Yanjun He ◽  
Tao Chen ◽  
Changchao She
Keyword(s):  
Stress Wave ◽  
Soft Rock ◽  
Vibration Signal ◽  
Slope Deformation ◽  
Additional Stress ◽  
Vibration Source ◽  
Blast Vibration ◽  
Vibration Displacement ◽  
Axial Acceleration ◽  
Point Distance

In order to study the cumulative blasting stress wave produced by the vibration of soft rock slope, the deformation regularity of the influence of blasting, caused by the horizontal and axial acceleration along with other additional stress waves were analyzed. The vibration displacement formula along with the vibration source stress wave superimposed model were established. The research also deduced the deformation rule for the gangue slope of Lijiahao Coal Mines as a vibration signal recorder was used to collect the blast vibration wave and the simulated analysis of displacement monitoring profile of the X and Y displacement rule under the influence of blast vibration were obtained. The results indicate that with the increase of the shot point distance, the displacement in the Y direction shows a logarithmic decline rule while the change in displacement of the X direction is small. The result also shows that the greater the initiation of multipoint shot firing, the greater the slope deformation and displacement of the rock mass and as a result multipoint nonsimultaneous blasting and control detonation time difference, can effectively reduce the effects of vibration on the slope deformation.

Study on Vibration Displacement of Ground Building Caused by Construction of Shallowly Bored Tunnel with Drill and Blast Method

2013 ◽  
Vol 838-841 ◽  
pp. 1359-1362
Author(s):  
Xiao Jun Zhou ◽  
Qi Sheng ◽  
Rui Guo
Keyword(s):  
Differential Equation ◽  
Mathematical Expression ◽  
Horizontal Displacement ◽  
Surrounding Rock ◽  
Rock Blasting ◽  
Blast Vibration ◽  
Vibration Displacement ◽  
Mathematical Formula ◽  
Main Factors ◽  
Drill And Blast

A mathematical formula to calculate relative horizontal displacement of ground building due to blast vibration of surrounding rock for bored tunnel by drill and blast method is propounded on the basis of differential equation for dynamic vibration, and the mathematical expression is deduced by means of Laplace transforms. The main factors which influence the horizontal displacement of ground building subject to rock blasting are also discussed in the paper.

scholarly journals SIGNAL PHASE SHIFTS DURING THE MEASUREMENT OF VIBRATION PARAMETERS

2020 ◽  
pp. 100-104
Author(s):  
Передерко А.Л., к.т.н.
Keyword(s):  
Vibration Signal ◽  
Wide Band ◽  
Phase Shifts ◽  
Vibration Velocity ◽  
Measured Signal ◽  
Mechanical Shock ◽  
Vibration Displacement ◽  
Active Vibration ◽  
Vibration Parameters ◽  
And Control

In systems of vibration control, monitoring, diagnostics, active vibration protection, measurements and control of vibration parameters are necessary. For this, piezoelectric sensors are widely used in them as primary transducers. These sensors, due to their high metrological characteristics, such as accuracy, speed, a wide band of operating frequencies and temperatures, are traditionally used to measure vibration displacement, vibration velocity and vibration acceleration. The use of these types of sensors is necessary due to the need to measure and control vibration at objects with different frequency characteristics. The article considers possible distortions of the measured signal at the output of the sensors due to phase shifts. These phase shifts must be taken into account when developing and constructing measurement and processing schemes of the vibration signal. This is especially true when measuring and recording a rapid vibration processes, such as mechanical shock.

Main frequency band of blast vibration signal based on wavelet packet transform

2019 ◽  
Vol 74 ◽  
pp. 569-585 ◽  
Author(s):  
Guan Chen ◽  
Qi-Yue Li ◽  
Dian-Qing Li ◽  
Zheng-Yu Wu ◽  
Yong Liu
Keyword(s):  
Frequency Band ◽  
Wavelet Packet ◽  
Vibration Signal ◽  
Wavelet Packet Transform ◽  
Blast Vibration ◽  
Main Frequency

The Research on the Methodology of Diagnosing the Fault of Bearing in Warships Based on NS-EMD

2013 ◽  
Vol 711 ◽  
pp. 352-357
Author(s):  
Jin E Huang ◽  
Dong Xu ◽  
Yan Lei Wang ◽  
Yang Zhang ◽  
Shuang Wang
Keyword(s):  
Signal Processing ◽  
Vibration Signal ◽  
Rolling Bearing ◽  
Processing Method ◽  
Image Method ◽  
Vibration Source ◽  
Rolling Bearings ◽  
Average Value ◽  
Signal Processing Method ◽  
Emd Method

EMD is now a commonly used nonlinear and instable signal processing method, but it has boundary runaway and modal aliasing. The single disunited IMF cannot well reflect the characteristics of the respective vibration source. Therefore, in order to suppress the boundary runaway that will appear in the process of EMD, the image method is used to extend the length of signal data. To solve the modal aliasing, it is necessary to decompose the extended data by the EMD method, to distinguish the IMF that produces modal aliasing after decomposition, to integrate it according to the integrity of the EMD and then to re-decompose it after adding broadband white noise with the average value of zero. On the basis of that, it is better to improve NS-EMD method and realize the AM-FM demodulation by standardized method. By the spectrum analysis, we extract the fault characteristics of rolling bearings and propose a method to diagnose faults of rolling bearing. The results of analyzing the simulation and the vibration signal of fault rolling bearing shows that the method can effectively extract fault characteristics of rolling bearing.

The Design of a New Type of Spindle Vibration Test Device

2014 ◽  
Vol 556-562 ◽  
pp. 1460-1463
Author(s):  
Fang Dong ◽  
Jian Cheng Yang ◽  
Tian Zhu Gao ◽  
Yu Xie ◽  
Lei Guo ◽  
...  
Keyword(s):  
Virtual Instrument ◽  
Design Method ◽  
Movement Control ◽  
Vibration Signal ◽  
Mobile Systems ◽  
Vibration Test ◽  
Vibration Source ◽  
Motor Speed ◽  
Spindle Vibration ◽  
Analysis System

In this paper, a set of spindle vibration test equipment has been designed by using modern design method, on the basis of in-depth study of spindle vibration source .The device includes three parts: machinery, detection and control .In the mechanical part, using sensor fixed machine mobile systems, the design of the spindle drive part and test board was carried on respectively .In the detection part ,the virtual instrument Labview graphical programming language was adopted to form a spindle vibration test and analysis system, realizing the acquisition, processing and analysis of the vibration signal .In the control part, Yan Hua movement control cards are adopted to realize control of motor speed, through Labview programming.

Study on Oil Pipeline Leakage Detection Based on Stress Wave Detection Technique and Wavelet Analysis

2013 ◽  
Vol 694-697 ◽  
pp. 1368-1371
Author(s):  
Jie Zhang ◽  
Xiao Dan Guan ◽  
Yan Sun ◽  
Xue Jie Wei
Keyword(s):  
Wavelet Analysis ◽  
Stress Wave ◽  
Detection System ◽  
Vibration Signal ◽  
Detection Technique ◽  
Vibration Sensor ◽  
Processing Unit ◽  
Leakage Detection ◽  
Oil Pipeline ◽  
Wave Detection

Based on stress wave detection technique and wavelet analysis, oil pipeline leakage detection system is designed. Through vibration sensor put on the pipeline, vibration signal of pipeline is collected. The signal is used to preliminary assessment with DSP processing unit within the system, and then the feature of threat events is extracted. The information is uploaded to the centre of security central station of system by GPRS signal. At this, signal wavelet analysis is done for leakage detection. Based on LabVIEW platform, on oil pipeline leakage monitoring interface, threat events is alarmed and shown in electronic map and the system is convenient for staff to handle with. With the test, recognized police rate of system is superior to 85%, rate of false alarm is 15% below. All knocking signal of pipeline is given right alarm information. The noise by people walk, car, wind and rain is effectively filtered.

scholarly journals Influence of Tool Holder Types on Vibration in Rough Milling of AZ91D Magnesium Alloy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2517
Author(s):  
Ireneusz Zagórski ◽  
Jarosław Korpysa ◽  
Andrzej Weremczuk
Keyword(s):  
Magnesium Alloy ◽  
Vibration Signal ◽  
Multiscale Entropy ◽  
Machining Parameters ◽  
Technological Parameters ◽  
Vibration Displacement ◽  
Tool Holder ◽  
Az91d Magnesium Alloy ◽  
Rough Milling ◽  
Acceleration Signals

The article presents the results of an analysis of the influence of the technological parameters related to tool holder types on the vibrations occurring during the milling of AZ91D magnesium alloy. Magnesium alloys are very low-density materials and, therefore, are increasingly being considered as replacement materials for the more commonly used aluminium alloys. The tool used in the study was a carbide end mill with TiAlN coating, clamped in three different types of tool holder: ER collet, heat shrink, and Tendo E hydraulic. The milling tests used straight toolpaths at varied cutting speeds and feed per tooth values. Based on the vibration displacement and acceleration signals recorded during the machining tests, the following were analysed: maximum value, amplitude, and root mean square (RMS) value of the vibrations. As part of the study, composite multiscale entropy (CMSE) analysis was also performed, describing the level of disorderliness of the obtained vibration signals. The increase in machining parameters caused an increase in the values characterising the displacement and acceleration of the vibrations. It was noted that multiscale entropy might be an important parameter describing the vibration signal (both displacement and acceleration).

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