scholarly journals Complementary Relationship of High Speed Transportation in the Great East Japan Earthquake and Trends in the Reconstruction Period

2021 ◽  
Vol 73 (3) ◽  
pp. 164-177
Author(s):  
Youichirou UE ◽  
Motoo KUSHIBIKI
Keyword(s):  
High Speed ◽  
Great East Japan Earthquake ◽  
Complementary Relationship ◽  
Reconstruction Period ◽  
Relationship Of

Roller–rail parameters on the transverse vibration characteristics of super-high-speed elevators

2019 ◽  
Vol 43 (4) ◽  
pp. 535-543 ◽  
Author(s):  
Shunxin Cao ◽  
Ruijun Zhang ◽  
Shuohua Zhang ◽  
Shuai Qiao ◽  
Dongsheng Cong ◽  
...  
Keyword(s):  
High Speed ◽  
Relative Displacement ◽  
Guide Rail ◽  
Coupled Vibration ◽  
Vibration Acceleration ◽  
Vibration Model ◽  
Vibration Problems ◽  
Equivalent Method ◽  
Relationship Of ◽  
The Relationship

Interaction and wear between wheel and rail become increasingly serious with the increase in elevator speed and load. Uneven roller surface, eccentricity of rollers, and the looseness of rail brackets result in serious vibration problems of high-speed and super-high-speed elevators. Therefore, the forced vibration differential equation representing elevator guide rails is established based on Bernoulli–Euler theory, and the vibration equation of the elevator guide shoes and the car is constructed using the Darren Bell principle. Then, the coupled vibration model of guide rail, guide shoes, and car can be obtained using the relationship of force and relative displacement among these components. The roller–rail parameters are introduced into the established coupled vibration model using the model equivalent method. Then, the influence of roller–rail parameters on the horizontal vibration of super-high-speed elevator cars is investigated. Roller eccentricity and the vibration acceleration of the car present a linear correlation, with the amplitude of the car vibration acceleration increasing with the eccentricity of the roller. A nonlinear relationship exists between the surface roughness of the roller and the vibration acceleration of the car. Increased continuous loosening of the guide rail results in severe vibration of the car at the loose position of the support.

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

scholarly journals Focusing on and Backgrounding Events Simultaneously: The Past–Present–Future Relationship of the Great East Japan Earthquake

2018 ◽  
Vol 29 (1) ◽  
pp. 92-110
Author(s):  
Anja Danner-Schröder
Keyword(s):  
Great East Japan Earthquake ◽  
The Other ◽  
Temporal Orientation ◽  
The Past ◽  
Event Structures ◽  
Relationship Of ◽  
Over Time

This article examines how events from the past, present, and future form into event structures over time. This question is addressed by investigating the Great East Japan Earthquake in 2011 until the fifth anniversary in 2016. This allowed to analyze different events over time. The findings reveal that events can be used in two different ways. One process was meant to focus on events, whereas the other one backgrounded events. These different ways to use events revealed four different mechanisms of how event structures can be formed. Moreover, each mechanism has its own idiosyncratic temporal orientation toward either a nostalgic past, imagined future, “better” future or critical past. Second, the article contributes that the paradoxical ways of focusing on an event and backgrounding the very same event need to be embraced simultaneously to enable a greater sense of wholeness. Last, the article reveals multiple temporalities within and across temporal trajectories.

Experimental study on frictional loss of high-speed bearings based on free-deceleration and energy-balance methods

2019 ◽  
Vol 71 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Shengli Tian ◽  
Xiaoan Chen ◽  
Tianchi Chen ◽  
Ye He
Keyword(s):  
Energy Balance ◽  
Rotational Speed ◽  
High Speed ◽  
Mechanical Systems ◽  
Coupling Factor ◽  
Thermomechanical Coupling ◽  
Frictional Torque ◽  
Frictional Loss ◽  
Content Type ◽  
Relationship Of

Purpose The purpose of this study is to investigate accurate and effective experimental methods for measuring the frictional loss of bearings (FLB) in mechanical systems and to measure the effect of various operating parameters on the frictional loss of high-speed mechanical systems. Design/methodology/approach Two novel methods were studied in this paper to measure the FLB: the free-deceleration method and the energy-balance method. A special high-speed motorised spindle and a friction loss test rig were designed and built to measure the effects of rotational speed, lubrication, preload and operating temperature on the FLB. Findings The experimental results showed that the frictional torque of bearings increases initially but then decreases with an increase in rotational speed. Similarly, the FLB decreases initially and then increases with an increase in temperature because of the influence of the viscosity–temperature relationship of the lubricant and the thermomechanical coupling factor. The optimal lubricant flow was determined, and the effectiveness of a novel preload online adjusting device was verified through experiments. Originality/value The research results of this paper provide the basis and methods for the measurement, reduction and prediction of the FLB in mechanical systems.

scholarly journals Snap-jaw morphology is specialized for high-speed power amplification in the Dracula ant, Mystrium camillae

2018 ◽  
Vol 5 (12) ◽  
pp. 181447 ◽  
Author(s):  
Fredrick J. Larabee ◽  
Adrian A. Smith ◽  
Andrew V. Suarez
Keyword(s):  
High Speed ◽  
Muscle Power ◽  
Element Analysis ◽  
Predator Prey ◽  
Mantis Shrimp ◽  
Power Amplification ◽  
Form Function ◽  
Function Relationship ◽  
Relationship Of ◽  
Insight Into

What is the limit of animal speed and what mechanisms produce the fastest movements? More than natural history trivia, the answer provides key insight into the form–function relationship of musculoskeletal movement and can determine the outcome of predator–prey interactions. The fastest known animal movements belong to arthropods, including trap-jaw ants, mantis shrimp and froghoppers, that have incorporated latches and springs into their appendage systems to overcome the limits of muscle power. In contrast to these examples of power amplification, where separate structures act as latch and spring to accelerate an appendage, some animals use a ‘snap-jaw’ mechanism that incorporates the latch and spring on the accelerating appendage itself. We examined the kinematics and functional morphology of the Dracula ant, Mystrium camillae , who use a snap-jaw mechanism to quickly slide their mandibles across each other similar to a finger snap. Kinematic analysis of high-speed video revealed that snap-jaw ant mandibles complete their strike in as little as 23 µsec and reach peak velocities of 90 m s −1 , making them the fastest known animal appendage. Finite-element analysis demonstrated that snap-jaw mandibles were less stiff than biting non-power-amplified mandibles, consistent with their use as a flexible spring. These results extend our understanding of animal speed and demonstrate how small changes in morphology can result in dramatic differences in performance.

A LEAST‐SQUARES PROCEDURE FOR GRAVITY INTERPRETATION

Geophysics ◽  
1965 ◽  
Vol 30 (2) ◽  
pp. 228-233 ◽  
Author(s):  
Charles E. Corbató
Keyword(s):  
Least Squares ◽  
High Speed ◽  
Gravity Anomalies ◽  
The Body ◽  
Two Dimensional ◽  
Partial Derivatives ◽  
Dimensional Gravity ◽  
Gravity Interpretation ◽  
Relationship Of ◽  
Derivatives Of

A procedure suitable for use on high‐speed digital computers is presented for interpreting two‐dimensional gravity anomalies. In order to determine the shape of a disturbing mass with known density contrast, an initial model is assumed and gravity anomalies are calculated and compared with observed values at n points, where n is greater than the number of unknown variables (e.g. depths) of the model. Adjustments are then made to the model by a least‐squares approximation which uses the partial derivatives of the anomalies so that the residuals are reduced to a minimum. In comparison with other iterative techniques, convergence is very rapid. A convenient method to use for both the calculation of the anomalies and the adjustments is the two‐dimensional method of Talwani, Worzel, and Landisman, (1959) in which the outline of the body is polygonized and the anomalies and the partial derivatives of the anomaly with respect to the depth of a vertex on the body can be expressed as functions of the coordinates of the vertex. Not only depths but under certain circumstances regional gravity values may be evaluated; however, the relationship of the disturbing body to the gravity information may impose certain limitations on the application of the procedure.

Anatomical study of the ostrich (Struthio camelus) foot locomotor system

2016 ◽  
Author(s):  
Rui Zhang ◽  
Haitao Wang ◽  
Guiyin Zeng ◽  
Changhai Zhou ◽  
Runduo Pan ◽  
...  
Keyword(s):  
Theoretical Basis ◽  
High Speed ◽  
Three Dimensional ◽  
Gross Anatomy ◽  
Anatomical Study ◽  
Heavy Load ◽  
Locomotor System ◽  
Terrestrial Locomotion ◽  
Solid Foundation ◽  
Relationship Of

The Ostrich is a native bird of Africa, and is highly accomplished in terrestrial locomotion in desert and grassland environments. The foot is an important segment in the ostrich body, critical for damping vibration, absorbing energy, and maintaining balance; however, detailed information on the ostrich foot is sparse. In this study, the gross anatomy of locomotor system of the ostrich foot was investigated using dissection and medical scan modeling. The paper contains a detailed study of the organizational structure and relative positional relationship of bones, tendons, and ligaments, which can be used for further three-dimensional (3D) reconstruction, providing a solid foundation for the research of high speed, heavy load, and shock absorption mechanisms. The study also provides a theoretical basis for the research of robot travelling mechanisms and vehicles traversing desert or planetary terrain.

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