Dynamic Characteristic Analysis of Transmission Tower

2014 ◽  
Vol 494-495 ◽  
pp. 1719-1722
Author(s):  
Xiang Zan Xie ◽  
Ke Lun Wei
Keyword(s):  
Large Scale ◽  
Power Transmission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Modern Society ◽  
The Finite Element Method ◽  
Transmission Tower ◽  
Characteristic Analysis ◽  
Safety And Reliability ◽  
Three Dimensional Space

Transmission tower is a widely used higher order statically indeterminate spatial structure, as the pillar of power transmission, modern society are increasingly concerned about its safety and reliability. This paper establishes a large-scale three-dimensional space model of transmission tower by using the finite element method, calculate and analyse the first six vibration modes and frequencies of this transmission tower, study the characteristics of each order vibration mode. These research results provide some references of design for the large-scale transmission tower.

A method for the identification of trees with unusually colored foliage

1996 ◽  
Vol 26 (9) ◽  
pp. 1548-1555 ◽  
Author(s):  
John L. Innes ◽  
Sucharita Ghosh ◽  
Andreas Schwyzer
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Crown Condition ◽  
Normal Expectation ◽  
Three Dimensional Space

A method is presented for recognizing trees with unusually colored foliage, based on the use of Munsell plant color charts. Color assessments are made by scoring the crown of each tree for hue, value, and chroma. These values are plotted in three-dimensional space for each species, and a threshold is identified marking the border of an ellipsoid. Trees with foliage outside this ellipsoid are considered as unusual. The method means that assessments of discoloration can cover a range of colors and moves the decision over the color status of a tree from a subjective field decision to a statistically defined decision at the analytical stage. It takes into account that a tree may still be classified as green (previously classed as without discoloration) when its color of green lies outside the normal expectation for the species. The method represents a significant improvement on the discoloration assessments currently being used in large-scale inventories of crown condition in Europe.

scholarly journals The Group Evacuation Behavior Based on Fire Effect in the Complicated Three-Dimensional Space

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jun Hu ◽  
Huijun Sun ◽  
Ge Gao ◽  
Juan Wei ◽  
Lei You
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Target Position ◽  
Velocity Change ◽  
Evacuation Time ◽  
Evacuation Strategy ◽  
Average System ◽  
Evacuation Behavior ◽  
Three Dimensional Space

In order to effectively depict the group evacuation behavior in the complicated three-dimensional space, a novel pedestrian flow model is proposed with three-dimensional cellular automata. In this model the calculation methods of floor field and fire gain are elaborated at first, and the transition gain of target position at the next moment is defined. Then, in consideration of pedestrian intimacy and velocity change, the group evacuation strategy and evolution rules are given. Finally, the experiments were conducted with the simulation platform to study the relationships of evacuation time, pedestrian density, average system velocity, and smoke spreading velocity. The results had shown that large-scale group evacuation should be avoided, and in case of large pedestrian density, the shortest route of evacuation strategy would extend system evacuation time.

Large-scale dynamics in turbulent mixing and the three-dimensional space–time behaviour of outer fluid interfaces

2002 ◽  
Vol 471 ◽  
pp. 381-408 ◽  
Author(s):  
HARIS J. CATRAKIS ◽  
ROBERTO C. AGUIRRE ◽  
JESUS RUIZ-PLANCARTE ◽  
ROBERT D. THAYNE ◽  
BRENDA A. McDONALD ◽  
...  
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Space Time ◽  
Mixing Efficiency ◽  
Fluid Interfaces ◽  
Ambient Fluid ◽  
Wide Range ◽  
Dimensional Space Time ◽  
Three Dimensional Space

Experiments have been conducted to investigate turbulent mixing and the dynamics of outer fluid interfaces, i.e. the interfaces between mixed fluid and pure ambient fluid. A novel six-foot-diameter octagonal-tank flow facility was developed to enable the optical imaging of fluid interfaces above the mixing transition, corresponding to fully developed turbulence. Approximately 10003 whole-field three-dimensional space– time measurements of the concentration field were recorded using laser-induced- fluorescence digital-imaging techniques in turbulent jets at a Reynolds number of Re ∼ 20 000, Schmidt number of Sc ∼ 2000, and downstream distance of ∼ 500 nozzle diameters. Multiple large-scale regions of spatially nearly uniform-concentration fluid are evident in instantaneous visualizations, in agreement with previous findings above the mixing transition. The ensemble-averaged probability density function of concentration is found to exhibit linear dependence over a wide range of concentration thresholds. This can be accounted for in terms of the dynamics of large-scale well- mixed regions. Visualization of the three-dimensional space–time concentration field indicates that molecular mixing of entrained pure ambient fluid is dynamically initiated and accomplished in the vicinity of the unsteady large scales. Examination of the outer interfaces shows that they are dynamically confined primarily near the instantaneous large-scale boundaries of the flow. This behaviour is quantified in terms of the probability density of the location of the outer interfaces relative to the flow centreline and the probability of pure ambient fluid as a function of distance from the centreline. The current measurements show that the dynamics of outer interfaces above the mixing transition is significantly different from the behaviour below the transition, where previous studies have shown that unmixed ambient fluid can extend across a wide range of transverse locations in the flow interior. The present observations of dynamical confinement of the outer interfaces to the unsteady large scales, and considerations of entrainment, suggest that the mechanism responsible for this behaviour must be the coupling of large-scale flow dynamics with the presence of small-scale structures internal to the large-scale structures, above the mixing transition. The dynamics and structure of the outer interfaces across the entire range of space–time scales are quantified in terms of a distribution of generalized level-crossing scales. The outer-interface behaviour determines the mixing efficiency of the flow, i.e. fraction of mixed fluid. The present findings indicate that the large-scale dynamics of the outer interfaces above the mixing transition provides the dominant contribution to the mixing efficiency. This suggests a new way to quantify the mixing efficiency of turbulent flows at high Reynolds numbers.

Buckling Analysis of Large-Scale Transmission Tower Structure

2014 ◽  
Vol 494-495 ◽  
pp. 1678-1681
Author(s):  
Xiang Zan Xie ◽  
Rui Jun Zhang
Keyword(s):  
Transmission Lines ◽  
Large Scale ◽  
Power Transmission ◽  
Flexible Structures ◽  
Three Dimensional ◽  
Transmission Tower ◽  
Three Dimensional Model ◽  
Buckling Mode ◽  
Large Power ◽  
Tower Structure

The high-voltage transmission tower transmission lines is a major component and typically a high steel tower, is a tall, flexible structures. In this paper, the finite element method to establish a large-scale three-dimensional model of the transmission tower space, computational analysis of the transmission tower structure first six buckling modes and critical load, examined the order buckling mode characteristics. Research on the structural stability of large power transmission tower design has some theoretical significance and application value.

scholarly journals Approximate solution of the Signorini problem by the finite element method in three-dimensional space

2021 ◽  
Vol 21 (2) ◽  
pp. 203-214
Author(s):  
A.Y. Zolotukhin ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Approximate Solution ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Signorini Problem ◽  
The Finite Element Method ◽  
Three Dimensional Space ◽  
Element Method

The finite element method is usually used for two-dimensional space. The paper investigates the finite element method for solving the Signorini problem in three-dimensional space.

scholarly journals A Study on Intelligent GIS Installation System Based on Six-DOF Parallel Multi-axis Motion Control

2021 ◽  
Vol 2074 (1) ◽  
pp. 012066
Author(s):  
Ti Liu ◽  
Hongwei Mao ◽  
Dong Lei ◽  
Boming Li ◽  
Dahong Fu
Keyword(s):  
Motion Control ◽  
Power Transmission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Positioning System ◽  
Practical Applications ◽  
Visual Positioning ◽  
Six Dof ◽  
Six Degree Of Freedom ◽  
Three Dimensional Space

Abstract Aiming at the connection of pipelines during the GIS installation process of power transmission and transformation projects, this subject designs and produces an intelligent GIS installation system based on 6-DOF parallel multi-axis motion control, which is applied to practical applications. The intelligent installation system can realize six independent motions and their combined motions in three-dimensional space. Relying on the multi-dimensional visual positioning system, through the six-degree-of-freedom parallel multi-axis motion control system, the precise docking during the installation of the precision GIS cavity can be realized.

scholarly journals A framework for three-dimensional navigation research

2013 ◽  
Vol 36 (5) ◽  
pp. 571-587 ◽  
Author(s):  
Kathryn J. Jeffery ◽  
Aleksandar Jovalekic ◽  
Madeleine Verriotis ◽  
Robin Hayman
Keyword(s):  
Research Program ◽  
Large Scale ◽  
Dimensional Space ◽  
Comparative Cognition ◽  
Three Dimensional ◽  
Frames Of Reference ◽  
The Core ◽  
Theoretical Issues ◽  
Three Dimensional Space

AbstractWe have argued that the neurocognitive representation of large-scale, navigable three-dimensional space is anisotropic, having different properties in vertical versus horizontal dimensions. Three broad categories organize the experimental and theoretical issues raised by the commentators: (1) frames of reference, (2) comparative cognition, and (3) the role of experience. These categories contain the core of a research program to show how three-dimensional space is represented and used by humans and other animals.

scholarly journals A glimpse of fluid turbulence from the molecular scale

2014 ◽  
Vol 25 (08) ◽  
pp. 1450034 ◽  
Author(s):  
Teruhisa S. Komatsu ◽  
Shigenori Matsumoto ◽  
Takashi Shimada ◽  
Nobuyasu Ito
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Md Simulations ◽  
Energy Dissipation Rate ◽  
Coarse Grained ◽  
Fluid Turbulence ◽  
Molecular Scale ◽  
Decaying Turbulence ◽  
Three Dimensional Space

Large-scale molecular dynamics (MD) simulations of freely decaying turbulence in three-dimensional space are reported. Fluid components are defined from the microscopic states by eliminating thermal components from the coarse-grained fields. The energy spectrum of the fluid components is observed to scale reasonably well according to Kolmogorov scaling determined from the energy dissipation rate and the viscosity of the fluid, even though the Kolmogorov length is of the order of the molecular scale.

scholarly journals Neural encoding of large-scale three-dimensional space—properties and constraints

2015 ◽  
Vol 6 ◽  
Author(s):  
Kate J. Jeffery ◽  
Jonathan J. Wilson ◽  
Giulio Casali ◽  
Robin M. Hayman
Keyword(s):  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Neural Encoding ◽  
Three Dimensional Space
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