Movement process analysis of the high-speed long-runout Shuicheng landslide over 3-D complex terrain using a depth-averaged numerical model

Landslides ◽  
2021 ◽  
Author(s):  
Weihua Zhao ◽  
Xilin Xia ◽  
Xiaoli Su ◽  
Qiuhua Liang ◽  
Xiuwei Liu ◽  
...  
Keyword(s):  
Numerical Model ◽  
Complex Terrain ◽  
High Speed ◽  
Process Analysis ◽  
Long Runout ◽  
Movement Process

scholarly journals Dynamic Analysis of the High-Speed and Long-Runout Landslide Movement Process Based on the Discrete Element Method: A Case Study of the Shuicheng Landslide in Guizhou, China

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Guoqing Xia ◽  
Chun Liu ◽  
Chong Xu ◽  
Tiancheng Le
Keyword(s):  
Internal Friction ◽  
High Speed ◽  
Average Velocity ◽  
Source Area ◽  
Discrete Element ◽  
Frictional Heat ◽  
Long Runout ◽  
Movement Process ◽  
The Impact ◽  
Landslide Movement

On July 23, 2019, a high-speed and long-runout landslide occurred in Jichang Town, Shuicheng County, Guizhou Province, China, causing 42 deaths and 9 missing. This paper used the discrete element software MatDEM to construct a three-dimensional discrete element model based on digital elevation data and then simulated and analyzed the movement and accumulation process of the landslide. The maximum average velocity of the source area elements reached 14 m/s when passed through the scraping area; meanwhile, the velocity of the scraping area elements increased rapidly. At 90 s, the maximum displacement of the source area elements reached 1358.5 m. The heat generated during the movement of the landslide was mainly the frictional heat, and the frictional heat increased sharply when the source area elements passed through the scraping area. The change of frictional heat has a certain positive correlation with the velocity of the scraping area elements. Finally, the volume of the scraping area elements was 2.4 times greater than the source area elements in the deposits. The scraping effect increases the volume of the sliding body and expands the impact area of the landslide disaster. Additionally, by setting different compressive and tensile strengths as well as internal friction coefficients to analyze the influences of their value changes on the landslide movement process, the results show that the smaller the strengths and internal friction coefficient of the model, the greater the depth and area of the scraping area, which will result in a thicker accumulation; meanwhile, the average displacement, average velocity, and heat will also increase.

Automaton Fault Diagnosis Based on Chaos Theory

2013 ◽  
Vol 427-429 ◽  
pp. 697-701 ◽  
Author(s):  
Hong Xia Pan ◽  
Yun Peng Cui
Keyword(s):  
Fault Diagnosis ◽  
Chaos Theory ◽  
High Speed ◽  
Failure Modes ◽  
Process Analysis ◽  
Vibration Signal ◽  
Practical Significance ◽  
Movement Process ◽  
Impact Characteristics ◽  
First Time

The work of the automaton fault diagnosis based on experimental measurement has not been researched except the fund project which this paper was come from. First, study the structure characteristics, movement process and several common failure modes of the automaton. Then we combined the automaton movement process analysis and the nonlinear, short-term impact characteristics of the vibration signal, proposed for the first time with a powerful tool for nonlinear problem researchthe chaos theory, to research the fault diagnosis of automaton, and finally realized it. It provided a new way for the fault diagnosis of automatic weapons. That has important theoretical and practical significance for high speed automatic fault diagnosis.

Numerical Model Updating Technique for Estimating Load Carrying Capacities of High Speed Railway Bridges

2016 ◽  
Vol 106 (8) ◽  
pp. 490-497
Author(s):  
Dong-Uk PARK ◽  
Jae-Bong KIM ◽  
Nam-Sik KIM ◽  
Sung-Il KIM
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Model Updating ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Load Carrying

Practical Aspects of Propulsion Shaft Alignment

2021 ◽  
Author(s):  
Kyriakos Avgouleas ◽  
Emmanouil Sarris ◽  
George Gougoulidis
Keyword(s):  
Cost Effectiveness ◽  
Numerical Model ◽  
High Speed ◽  
The Other ◽  
Technical Literature ◽  
Trade Off ◽  
Fea Model ◽  
Shaft Alignment ◽  
Alignment Strategy ◽  
Potential Damage

The economical and operational implications of poor alignment are indisputable for the propulsion shafting system of a commercial vessel. This holds true for naval vessels as well, although far less documented in the technical literature. This paper addresses some of the challenges associated with the proper alignment of a high-speed naval craft, which has been in service for many years. Laser bore-sighting was performed on a Guided Missile Fast Patrol Boat resting on a docking cradle. The measured bearing offsets were input to a FEA model of the shafting system to calculate bearing reactions and detect potential misalignment issues. Subsequent decisions regarding corrective measures take into account the results computed by the numerical model, experience from sister ships, the available documentation from the building yard and several other factors which are discussed in the paper. The solutions proposed are targeted towards a balanced trade-off between cost effectiveness and out-of-service time on one hand, and the risk of potential damage from misalignment on the other hand, which would seriously disrupt the ship’s operational availability. Practical aspects and lessons identified in the process are also presented, which demonstrate the distinct differences in alignment strategy of a high-speed naval craft compared to a typical commercial vessel.

Some Observations of Chaotic Vibration Phenomena in High-Speed Rotordynamics

1991 ◽  
Vol 113 (1) ◽  
pp. 50-57 ◽  
Author(s):  
F. F. Ehrich
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Chaotic Behavior ◽  
Narrow Region ◽  
System A ◽  
Vibratory Response ◽  
Local Contact ◽  
Jeffcott Rotor ◽  
Subharmonic Response ◽  
Static Part

Subharmonic response in rotordynamics may be encountered when a rotor is operated with its rotational centerline eccentric to that of a close clearance static part, so that local contact can take place during each orbit when the rotor is excited by residual unbalance. The rotor will tend to bounce at or near its fundamental frequency when the rotor is operated at or near a speed which is a whole number [n] times that frequency. Using a simple numerical model of a Jeffcott rotor mounted on a nonlinear spring, it is found that the vibratory response in the transition zone midway between adjacent zones of subharmonic response has all the characteristics of chaotic behavior. The transition from subharmonic to chaotic response has a complex substructure which involves a sequence of bifurcations of the orbit with variations in speed. This class of rotordynamic behavior was confirmed and illustrated by experimental observations of the vibratory response of a high-speed turbomachine, operating at a speed between 8 and 9 times its fundamental rotor frequency when in local contact across a clearance in the support system. A narrow region between zones of 8th order and 9th order subharmonic response was identified where the response had all the characteristics of the chaotic motion identified in the numerical model.

scholarly journals A simple and efficient numerical model for dynamic interaction of high speed train and railway structure including derailment during an earthquake

2017 ◽  
Vol 199 ◽  
pp. 2729-2734 ◽  
Author(s):  
M. Tanabe ◽  
K. Goto ◽  
T. Watanabe ◽  
M. Sogabe ◽  
H. Wakui ◽  
...  
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Dynamic Interaction ◽  
High Speed Train

Process Optimization of Ultrasonic Shot Peening by Realistic Modeling of Beads Motion

2014 ◽  
Author(s):  
Alexandre Brosse ◽  
Simon Le Moal ◽  
Rémi Lacroix ◽  
Philippe Mourgue ◽  
Vincent Robin ◽  
...  
Keyword(s):  
Numerical Model ◽  
Shot Peening ◽  
High Frequency ◽  
High Speed ◽  
Nuclear Industry ◽  
Input Frequency ◽  
Realistic Modeling ◽  
Ultrasonic Shot Peening ◽  
Small Steel

In the nuclear industry surface mechanical treatments are used in order to improve the surface integrity of the component, which increases their lifetime regarding corrosion and fatigue damages. A good understanding of these processes and their consequences is required to ensure the efficiency and perpetuity of such mitigation treatment. This study focuses on the ultrasonic shot peening process. It consists in shooting at high speed small steel beads on the part to be treated by using a high frequency vibration device. Parameters such as the number and the size of beads, the input frequency and the dimensions of the chamber can induce large ranges of impact velocity and coverage. In order to help manufacturers to control the treatment applied on their components, a numerical model has been developed. It accounts for the shocks of the beads against the walls of the chamber, the peening head and between beads, describing their motions accurately. In this paper, we will introduce the numerical model developed to simulate the motions of beads in the peening chamber. Special attention will be taken to the determination of the restitution rates related to the different materials. Results of the model will be shown for different process parameter (e.g. the number of beads), and a thorough analysis of their effects on the workpiece will be presented, including a comparison with some experimental results.

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