A Numerical Study of Tsunami Generation by Horizontal Displacement of Sloping Seafloor

2020 ◽  
Vol 14 (04) ◽  
pp. 2050018 ◽  
Author(s):  
Chentong Hu ◽  
Yifan Wu ◽  
Chao An ◽  
Hua Liu
Keyword(s):  
Numerical Study ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Horizontal Motion ◽  
Generation Process ◽  
Tsunami Generation ◽  
Initial Water ◽  
Horizontal Momentum ◽  
The Difference ◽  
Water Elevation

Tsunamis are generated primarily by the vertical displacement of the seafloor if the seafloor is flat. If the seafloor is slanted, the horizontal motion also contributes to the generation of tsunamis. A previous study proposed that such effects can be estimated by simply calculating the elevation of water due to the horizontal displacement of the slope. Two more studies later argued that the horizontal motion also results in horizontal momentum of the water, which amplifies the tsunami generation. In this study, we numerically simulate the tsunami generation process of flat and sloping seafloor. It is found that, for the flat seafloor, the initial water elevation equals the vertical seafloor displacement. For the sloping seafloor, the initial water elevation deviates from the vertical seafloor displacement, and the difference can be accurately evaluated by the horizontal seafloor displacement. Thus, the initial horizontal momentum of the water is negligible for tsunami generation.

Time-dependent Tsunami Source Following the 2018 Anak Krakatau Volcano Eruption Inferred from Nearby Tsunami Recordings

2020 ◽  
Author(s):  
Yifan Zhu ◽  
Chao An ◽  
Teng Wang ◽  
Hua Liu
Keyword(s):  
Source Region ◽  
Time Dependent ◽  
Tsunami Source ◽  
Water Volume ◽  
Generation Process ◽  
Tsunami Generation ◽  
Time Duration ◽  
Initial Water ◽  
Volcano Eruption ◽  
Krakatau Volcano

Abstract The eruption of the Anak Krakatau volcano, Indonesia, on 22 December 2018 induced a destructive tsunami (the Sunda Strait tsunami), which was recorded by four nearby tidal gauges. In this study we invert the tsunami records and recover the tsunami generation process. Two tsunami sources are obtained, a static one of instant initial water elevation and a time-dependent one accounting for the continuous evolution of water height. The time-dependent results are found to reproduce the tsunami recordings more satisfactorily. The complete tsunami generation process lasts approximately 9 min and features a two-stage evolution with similar intensity. Each stage lasts about 3.5 min and elevates a water volume of about 0.15 km 3 . The time, duration and volume of the volcano eruption in general agree with seismic records and geomorphological interpretations. We also test different sizes of the potential source region, which lead to different maximum wave height in the source area, but all the results of time-dependent tsunami sources show the robust feature of two stages of wave generation. Our results imply a time-dependent and complex process of tsunami generation during the volcano eruption.

The Fitting Analysis of the Miscellaneous Filled Slope Deformation Monitoring

2013 ◽  
Vol 838-841 ◽  
pp. 761-767
Author(s):  
Da Wei Zheng ◽  
Shuai Li ◽  
Yi Meng Zhao
Keyword(s):  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Displacement Monitoring ◽  
Engineering Construction ◽  
Scheme Optimization ◽  
Construction Scheme ◽  
Simulation Results ◽  
The Difference

In this paper, through the analysis of miscellaneous fill slope horizontal displacement of supporting structure and the vertical displacement monitoring results, the simulation results are compared and analyzed with FLAC3Dsoftware, verify the support form the deformation in the controllable range, the actual monitoring data and simulation results in the difference between the standard allows range, fitting deformation curve can be used as a conventional deformation monitoring based on integral deformation analysis, advanced demonstration of engineering construction scheme optimization.

scholarly journals Comparison on the Horizontal Behaviors of Lattice-Shaped Diaphragm Wall and Pile Group under Static and Seismic Loads

2016 ◽  
Vol 2016 ◽  
pp. 1-17
Author(s):  
Jiu-jiang Wu ◽  
Qian-gong Cheng ◽  
Hua Wen ◽  
Yan Li ◽  
Jian-lei Zhang ◽  
...  
Keyword(s):  
Numerical Study ◽  
Soft Soil ◽  
Horizontal Displacement ◽  
Pile Group ◽  
Diaphragm Wall ◽  
Deformation Pattern ◽  
Soil Core ◽  
Acceleration Amplification ◽  
The Difference ◽  
Bridge Foundation

Lattice-shaped diaphragm wall (hereafter referring to LSDW) is a new type of bridge foundation, and the relevant investigation on its horizontal behaviors is scant. This paper is devoted to the numerical study of the comparison on the static and seismic responses of LSDW and pile group under similar material quantity in soft soil. It can be found that the horizontal bearing capacity of LSDW is considerably larger than that of pile group, and the deformation pattern of LSDW basically appears to be an overall toppling while pile group clearly shows a local bending deformation pattern during the static loading process. The acceleration response and the acceleration amplification effects of LSDW are slightly greater than that of pile group due to the existing of soil core and the difference on the ability of energy dissipation. The horizontal displacement response of pile group is close to that of LSDW at first and becomes stronger than that of LSDW due to the generation of plastic soil deformation near the pile-soil interface at last. The pile body may be broken in larger potential than LSDW especially when its horizontal displacement is notable. Compared with pile group, LSDW can be a good option for being served as a lateral bearing or an earthquake-proof foundation in soft soil.

Nonlinear dynamic behaviour of guy cables in turbulent winds

2001 ◽  
Vol 28 (1) ◽  
pp. 98-110 ◽  
Author(s):  
Bruce F Sparling ◽  
Alan G Davenport
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Aerodynamic Drag ◽  
Numerical Study ◽  
Horizontal Displacement ◽  
Wind Loading ◽  
Second Phase ◽  
Nonlinear Coupling ◽  
Wide Range ◽  
Cable Vibrations

Large amplitude cable vibrations are difficult to predict using linear theory due to the presence of sag in the suspended profile. A numerical study was therefore undertaken to investigate the dynamic behaviour of inclined cables excited by imposed displacements. To model the nonlinear nature of cable response, a time domain finite element approach was adopted using nonlinear catenary cable elements. Two types of horizontal displacement patterns were enforced at the upper end of the guy. In the first phase of the study, harmonic displacement histories with a wide range of forcing frequencies were considered. In the second phase, random enforced displacements were used to simulate the motion of a guyed mast in gusty winds. The influence of aerodynamic drag and damping forces was investigated by performing analyses under still air, steady wind, and turbulent wind conditions. It was found that nonlinear coupling of related harmonic response components was significant at certain critical frequencies, particular when the excitation was harmonic and acted in the plane of the guy. Positive aerodynamic damping was shown to effectively suppress resonant and nonlinear coupling response.Key words: cables, structural dynamics, wind loading, finite element method, nonlinear analysis, guyed towers.

Experimental and Numerical Study on Grinding Temperature during Surface Grinding with Different Cooling Methods

2009 ◽  
Vol 416 ◽  
pp. 514-518 ◽  
Author(s):  
Qing Long An ◽  
Yu Can Fu ◽  
Jiu Hua Xu
Keyword(s):  
Numerical Study ◽  
Specific Energy Consumption ◽  
Ground Surface ◽  
Numerical Results ◽  
Surface Grinding ◽  
Grinding Temperature ◽  
Air Jet ◽  
The Difference ◽  
High Specific Energy ◽  
Cooling Methods

Grinding, characterized by its high specific energy consumption, may generate high grinding zone temperature. These can cause thermal damage to the ground surface and poor surface integrity, especially in the grinding of difficult-to-machine materials. In this paper, experimental and fem study on grinding temperature during surface grinding of Ti-6Al-4V with different cooling methods. A comparison between the experimental and numerical results is made. It is indicated that the difference between experimental and numerical results is below 15% and the numerical results can be considered reliable. Grinding temperature can be more effectively reduced with CPMJ than that with cold air jet and flood cooling method.

scholarly journals Influence of rigidity of retainers on dynamic behavior of implant-supported removable partial dentures

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Toshifumi Nogawa ◽  
Masayasu Saito ◽  
Naomichi Murashima ◽  
Yoshiyuki Takayama ◽  
Atsuro Yokoyama
Keyword(s):  
Dynamic Behavior ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Denture Base ◽  
Second Molar ◽  
Mechanical Simulation ◽  
Computed Tomography Images ◽  
Significant Difference ◽  
Abutment Teeth ◽  
Distal Extension

Abstract Background Implant-supported removable partial dentures (ISRPDs) are an effective treatment for partially edentulous patients. ISRPDs improve patients’ satisfaction and oral function to a greater extent than RPDs by improving denture stability and enhancing support. However, the effect of a type of direct retainer on displacement of the abutment teeth and dentures in ISRPDs remains unclear. Therefore, we made a resin mandibular model of unilateral mandibular distal-extension partial edentulism for mechanical simulation and compared the dynamic behavior of the abutment teeth and the denture base among different tooth-borne retainers with various rigidities for RPDs and ISRPDs. Methods A resin mandibular model for mechanical simulation that had unilateral mandibular distal-extension edentulism and was missing the first molar, second molar, first premolar, and second premolar, and a denture fabricated from the patient’s computed tomography images were used. Three types of direct retainers with different connecting rigidities were evaluated. The vertical displacement of the denture base and buccal and lingual sides and the mesial displacement of the abutment teeth were measured. Results Regardless of the rigidity of the direct retainers and loading positions, the displacement of the denture bases in the ISRPDs was significantly smaller than that in the RPDs (P < 0.001). There was no significant difference in vertical displacement of the denture bases among direct retainers with various connecting rigidities in the ISRPDs. Conversely, horizontal displacement of the abutment teeth in both the RPDs and ISRPDs tended to be larger with the cone crown telescope, which has high rigidity, than with the cast cingulum rest and wire clasp, which have much lower rigidities. Conclusion Our results suggested that cast cingulum rest and wire clasps as direct retainers are appropriate ISRPDs to minimize denture movement and suppress displacement of the remaining teeth in patients with unilateral mandibular distal-extension partial edentulism.

Study on the difference in the exciton generation process for the single-host and the exciplex-type co-host

2021 ◽  
Author(s):  
huiwen xu ◽  
jinyu lin ◽  
Xinyan Jiang ◽  
yu jin ◽  
Zhili LIN ◽  
...  
Keyword(s):  
Generation Process ◽  
Single Host ◽  
The Difference

The Cedar Mountain, Nevada, earthquake of December 20, 1932*

1934 ◽  
Vol 24 (4) ◽  
pp. 345-384 ◽  
Author(s):  
Vincent P. Gianella ◽  
Eugene Callaghan
Keyword(s):  
Sierra Nevada ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Relative Movement ◽  
East Side ◽  
Owens Valley ◽  
The West ◽  
Horizontal Movement ◽  
San Andreas

Summary The Cedar Mountain, Nevada, earthquake took place at about 10h 10m 04s p.m., December 20, 1932. It was preceded by a foreshock noted locally and followed by thousands of aftershocks, which were reported as still continuing in January 1934. No lives were lost and there was very little damage. The earthquake originated in southwest central Nevada, east of Mina. A belt of rifts or faults in echelon lies in the valley between Gabbs Valley Range and Pilot Mountains on the west and Cedar Mountain and Paradise Range on the east. The length of this belt is thirty-eight miles in a northwesterly direction, and the width ranges from four to nine miles. The rifts consist of zones of fissures which commonly reveal vertical displacement and in a number of places show horizontal displacement. The length of the rifts ranges from a few hundred feet to nearly four miles, and the width may be as much as 400 feet. The actual as well as indicated horizontal displacement is represented by a relative southward movement of the east side of each rift. The echelon pattern of the rifts within the rift area indicates that the relative movement of the adjoining mountain masses is the same. The direction of relative horizontal movement corresponds to that along the east front of the Sierra Nevada at Owens Valley and on the San Andreas rift.

Enhancement of Full Coverage Film Cooling Effectiveness with Mixed Injection Holes

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Mukesh Prakash Mishra ◽  
A K Sahani ◽  
Sunil Chandel ◽  
R K Mishra
Keyword(s):  
Film Cooling ◽  
Numerical Study ◽  
Velocity Ratio ◽  
Perforated Plate ◽  
Combustion Chambers ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Full Coverage ◽  
Upstream Direction ◽  
The Difference

Abstract In the present work numerical study of full coverage film cooling on an adiabatic flat plate is carried out. Cooling performance of three configurations of cylindrical holes is studied with downstream injection, upstream injection and mixed injection. In mixed injection configuration one column of holes inject in downstream direction and the holes in the adjacent column inject in the upstream direction. Numerical simulations are carried out at different velocity ratios and circumferentially averaged value of adiabatic film cooling effectiveness is estimated. Simulation results indicate that the mixed injection configuration has better and more uniform cooling, throughout the perforated plate, than with downstream injection. The difference is greater with increase in the velocity ratio. Configuration with upstream injection gives better cooling than mixed injection at front few rows of cooling holes but it shows poorer performance with downstream injection in the downstream rows of cooling holes. The obtained results from this study can be an invaluable input for highly loaded combustion chambers.

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