scholarly journals Operability of threaded and studded joints under intense vibration load

2019 ◽  
Vol 3 (389) ◽  
pp. 173-179
Author(s):  
S. Zenkov ◽  
Keyword(s):  
Vibration Load ◽  
Intense Vibration

The effects of intense vibration.

1958 ◽  
Author(s):  
A. J. Riopelle ◽  
Marion Hines ◽  
Merle Lawrence
Keyword(s):  
Intense Vibration

Response Law and Influencing Factors of the Soil under Action of Pile Driving Vibration Based on Midas/GTS

2013 ◽  
Vol 353-356 ◽  
pp. 979-983
Author(s):  
Dong Zhang ◽  
Jing Bo Su ◽  
Hui De Zhao ◽  
Hai Yan Wang
Keyword(s):  
Damping Ratio ◽  
Large Diameter ◽  
Time History ◽  
Pile Driving ◽  
Analysis Model ◽  
Vibration Load ◽  
History Analysis ◽  
Study Results ◽  
Propagation Law ◽  
Dynamic Time

Due to the upgrade and reconstruct of a high-piled wharf, the piling construction may cause the damage of the large diameter underground pipe of a power plant nearby. For this problem, a dynamic time-history analysis model was established using MIDAS/GTS program. Based on the analysis of the pile driving vibration and its propagation law, some parameters, such as the modulus of the soil, the Poissons ratio of soil, the action time of vibration load and the damping ratio of the soil that may have an effect on the response law of the soil, were studied. The study results not only serve as an important inference to the construction of this case, but also accumulate experience and data for other similar engineering practices.

scholarly journals Rock Particle Motion Information Detection Based on Video Instance Segmentation

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4108
Author(s):  
Man Chen ◽  
Maojun Li ◽  
Yiwei Li ◽  
Wukun Yi
Keyword(s):  
Loss Function ◽  
Particle Motion ◽  
Numerical Models ◽  
Major Axis ◽  
Angular Distance ◽  
Motion Information ◽  
Vibration Load ◽  
Rock Particle ◽  
Information Detection ◽  
Instance Segmentation

The detection of rock particle motion information is the basis for revealing particle motion laws and quantitative analysis. Such a task is crucial in guiding engineering construction, preventing geological disasters, and verifying numerical models of particles. We propose a machine vision method based on video instance segmentation (VIS) to address the motion information detection problem in rock particles under a vibration load. First, we designed a classification loss function based on Arcface loss to improve the Mask R-CNN. This loss function introduces an angular distance based on SoftMax loss that distinguishes the objects and backgrounds with higher similarity. Second, this method combines the abovementioned Mask R-CNN and Deep Simple Online and Real-time Tracking (Deep SORT) to perform rock particle detection, segmentation, and tracking. Third, we utilized the equivalent ellipse characterization method for segmented particles, integrating with the proportional calibration algorithm to test the translation and detecting the rotation by calculating the change in the angle of the ellipse’s major axis. The experimental results show that the improved Mask R-CNN obtains an accuracy of 93.36% on a self-created dataset and also has some advantages on public datasets. Combining the improved Mask R-CNN and Deep SORT could fulfill the VIS with a low ID switching rate while successfully detecting movement information. The average detection errors of translation and rotation are 5.10% and 14.49%, respectively. This study provides an intelligent scheme for detecting movement information of rock particles.

scholarly journals Research on Transfer Characteristics of Engine Vibration Load to Cabin Seat

2020 ◽  
Vol 38 (6) ◽  
pp. 1163-1170
Author(s):  
Juncheng Shu ◽  
Erming He ◽  
Jinxiang Yi ◽  
Pengxiang Chen
Keyword(s):  
Vibration Isolation ◽  
Vertical Direction ◽  
Frequency Component ◽  
Vertical Acceleration ◽  
Load Spectrum ◽  
Contribution Rate ◽  
Vibration Transmission ◽  
Vibration Load ◽  
Engine Vibration ◽  
Double Beam

Aeroengine is one of the main vibration sources that affect the passenger comfort. The contribution of engine vibration to the vibration response of seat will provide basic data for the design of airliner vibration comfort and engine vibration isolation installation. Firstly, the dynamical model of middle fuselage compartment with double-beam wing was established. Then, based on the typical vibration load spectrum of the engine, the acceleration responses of the key nodes of the wing beam and the seat connection points were analyzed, and the main path of engine vibration transmission to seats was identified. Finally, using operational transfer path analysis (OTPA) method, the contribution of engine front and rear mount point vibration to the vertical acceleration response of the seats was compared, and the three-dimensional information of wing structure vibration transmission was explored. The results show that the fundamental frequency component of low-pressure rotor of engine vibration has the greatest impact on the seat vertical response under takeoff and cruise conditions, the contribution rate of the front mount point vibration is about 71% and 67% respectively. However, the fundamental and its 3/2 times frequency components of high-pressure rotor have relatively large impact on the seats vertical response under flight idle state, and the contribution rate of engine front mount point vibration is about 45% and 60% respectively. In addition, the engine vibration is mainly transmitted from the wing front beam to the seat vertical response. The vertical direction of the wing beam and the rotation direction around the fuselage are also the main direction of vibration transmission.

Modal Analysis of Axial Vibration of Long Pipeline Delivering Coal Slime in Power Plant

2015 ◽  
Vol 740 ◽  
pp. 112-115
Author(s):  
Qing Wei Shi ◽  
Ya Yun Liu ◽  
Xing Lu Liu ◽  
Xue Di Hao
Keyword(s):  
Finite Element ◽  
Power Plant ◽  
Modal Analysis ◽  
Element Model ◽  
Vibration Characteristics ◽  
Axial Vibration ◽  
Coal Slime ◽  
Pipeline Vibration ◽  
The Finite Element Model ◽  
Intense Vibration

Aiming at the problem of intense vibration of the long pipeline delivering coal slime in the power plant, the finite element model of pipeline is established and modal analysis is carried out by ANSYS. The natural frequency and vibration characteristics of axial vibration are obtained. The vibration characteristics are studied and different pipe segments that produce bigger vibration very easily in operation are determined. Theoretical guidance about pipeline vibration under the external load for further analysis is provided.

scholarly journals A Study on Dynamic Amplification Factor and Structure Parameter of Bridge Deck Pavement Based on Bridge Deck Pavement Roughness

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Fei Han ◽  
Dan-hui Dan ◽  
Hu Wang
Keyword(s):  
Bridge Deck ◽  
Amplification Factor ◽  
Amplification Coefficient ◽  
Dynamic Amplification Factor ◽  
Vibration Load ◽  
Pavement Roughness ◽  
Composite Bridge ◽  
Dynamic Amplification ◽  
Cushion Layer ◽  
Bridge Deck Pavement

In order to study the coupled influence of deck pavement roughness and velocity on dynamic amplification factor, a 2-DOF 1/4 vehicle model is employed to establish the vehicle-bridge-coupled vibration system. The random dynamic load of running vehicle simulated by software MATLAB is applied on bridge deck pavement (BDP) through ANSYS software. Besides, the influence of BDP parameters on control stress under static load and random vibration load is analyzed. The results show that if the surface of BDP is smooth, the dynamic magnification coefficient would first increase and then decrease with increasing of vehicle velocity and reach its maximum value when v = 20 m/s; if the surface of BDP is rough, the maximal and minimum values of the dynamic amplification coefficient (DAC) occur, respectively, when the velocity reaches 10 m/s and 15 m/s. For a composite bridge deck with the cushion layer, the thickness of asphalt pavement should be not too thick or thin and better to be controlled for about 10 cm; with the increasing of cushion layer thickness, the control stress of deck pavement is all decreased and show similar change regularity under effect of different loads. In view of self-weight of structure, the thickness of the cushion layer is recommended to be controlled for about 4 cm.

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