scholarly journals Uplift Bearing Capacity of Cone-Cylinder Foundation for Transmission Line in Frozen Soil Regions, Using Reduced-Scale Model Tests and Numerical Simulations

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2066
Author(s):  
Yangchun Han ◽  
Jiulong Cheng ◽  
Qiang Cui ◽  
Qianyun Dong ◽  
Wanting Song
Keyword(s):  
Transmission Line ◽  
Numerical Simulations ◽  
Bearing Capacity ◽  
Frozen Soil ◽  
Scale Model ◽  
Three Dimension ◽  
Scale Modeling ◽  
Bottom Width ◽  
The Impact ◽  
Reduced Scale

In order to analyze the uplift bearing capacity of cone-cylinder foundation for transmission line in frozen soil regions, a series of reduced-scale modeling tests and numerical simulations are carried out. First, three reduced-scale cone-cylinder foundations with the same sizes, that are five times smaller than the prototype, are made and then loaded under uplift load at −5 °C, −10 °C, and −15 °C, respectively. On this basis, the foundations of nine sizes are modeled and loaded by numerical simulation. The impact of three dimension factors, including the ratio of depth to bottom width ( λ = h t / D t ), the top diameter of the cone-cylinder (d), and the bottom diameter of the cone-cylinder (D), on the uplift bearing capacity of foundations have been investigated. The results reveal that, for cone-cylinder foundation, the uplift bearing capacity is obviously affected by the freezing temperatures and the foundation sizes. The capacity is negatively correlated with the former. Whereas the order of correlation with the latter is as follows: λ, D, and d based on the comprehensive results of range and variance analysis, but none of them are the significant factors, according to the F-test. Furthermore, three failure mechanisms of frozen soil are distinguished and named T-mode, V-mode, and U-mode, respectively. Based on the above results, the bearing mechanism of cone-cylinder foundation in frozen soil is elaborated in detail.

Experimental Set-Up for Analysis of Subsea Equipment Installation

2011 ◽  
Author(s):  
Pedro C. de Mello ◽  
Felipe Rateiro ◽  
Andre´ L. C. Fujarra ◽  
Anderson T. Oshiro ◽  
Cassiano R. Neves ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Companion Paper ◽  
Scale Model ◽  
Illustrative Case ◽  
Preliminary Evaluation ◽  
Hydrodynamic Properties ◽  
Wave Basin ◽  
Servo Actuator ◽  
Induced Motion ◽  
Reduced Scale

This paper and the companion paper (Rateiro et al., 2011) present an illustrative case of the joint application of experimental tests and numerical simulations for the proper analysis of a complex offshore operation (launching of a sub-sea equipment using one or two vessels). The main idea of the whole study is to compare two methodologies and operational procedures for the installation of the equipment in the seabed, using either one vessel (conventional operation) or two vessels in a synchronized operation in a Y-configuration. The experiment was conducted under a simplified configuration, and uses ODF (one degree of freedom) servo-actuator to emulate the vessels induced motion. The hydrodynamic properties of the equipment was then calculated, and some preliminary conclusions about system dynamics could also be drawn. After that, numerical simulations were conducted, considering the coupled dynamics of the vessels, cables and equipments under irregular sea state. Those simulations were used for determining the limiting environmental condition for a safe operation, and are described in the companion paper. This paper describes the reduced scale experimental setup used for evaluating the hydrodynamic properties of the equipment during a subsea installation under waves excitation. The reduced scale model of the equipment was attached to one or two servo-actuator, that emulate the wave-induced motion. The tests were conducted at the physical wave basin of Numerical Offshore Tank (Tanque de Provas Nume´rico – TPN). The experiments enabled the preliminary evaluation of the dynamic behavior of the equipment when submerged by one or two launching cables. In the later case (two launching cables), several tests considering phase shifts between the servo-actuator have been conducted. The reduction in the dynamic amplification of cable traction could also be experimentally verified.

scholarly journals Small Scale Experiments to Assess the Bearing Capacity of Footings on the Sloped Surface

Eng ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 240-248
Author(s):  
Mohammad Nurul Islam
Keyword(s):  
Bearing Capacity ◽  
Carrying Capacity ◽  
Maximum Load ◽  
Scale Model ◽  
Small Scale ◽  
Load Carrying Capacity ◽  
Engineering Structures ◽  
Load Carrying ◽  
Limiting Condition ◽  
The Impact

Construction of civil engineering structures on or next to a slope requires special attention to meet the bearing capacity requirements of soils. In this paper, to address such a challenge, we present laboratory-scale model tests to investigate the effect of footing shape on the sloped surface. The model comprised of a well stiffened mild steel box with three sides fixed and one side open. We considered both with and without reinforcement to assess the effectiveness of reinforcement on the sloped surface. Also, we used three types of footing (i.e., square, rectangular, and circular) to measure the footing shape effects. We considered three different slope angles to evaluate the impact of the sloped face corresponding to the applied load and the reinforcement application. We obtained that the maximum load carrying capacity in the square footing was higher than the rectangular and the circular footing for both the reinforced and the unreinforced soil. With the increase of geo-reinforcement in all three footing shapes and three sloped angles, the load carrying capacity increased. We also noticed a limiting condition in geo-reinforcement placement effectiveness. And we found that with the increase of slope, the load bearing capacity decreased. For a steep slope, the geo-reinforcement placement and the footing shape selection is crucial in achieving the external load sustainability, which we addressed herein.

Hot Radial Upset-Extruding Process for Tube Structure with a Nozzle of 316LN Stainless Steel

2014 ◽  
Vol 1004-1005 ◽  
pp. 1245-1255
Author(s):  
Xin Wang ◽  
Xiao Feng ◽  
Lei Zhang ◽  
Feng Lin ◽  
Ji Luan Pan
Keyword(s):  
Metal Flow ◽  
Scale Model ◽  
Pure Lead ◽  
Main Pipe ◽  
Tube Billet ◽  
Plastic Forming ◽  
Radial Outflow ◽  
The Impact ◽  
Reduced Scale ◽  
Tube Structure

AP1000 nuclear power main pipe, a type of complicated thick-walled tube structure with both high and thick-walled nozzles, is one of the key parts in nuclear island. It is required to be manufactured by integral plastic forming technique. Up to now, no economical and efficient plastic forming process for AP1000 main pipe has been reported. To aim for forming the tube structure with a nozzle such as AP1000 main pipe, a radial upset-extruding (RUE) process was developed, in which the initial billet is an extruded tube with a hole. RUE process is an extrusion method which realizes radial outflow of the metal around the hole of tube billet through an axial upsetting force and restriction of dies. Thick-walled tube structure with a nozzle derived from AP1000 main pipe was simplified to be a thick-walled three-way pipe, on which RUE process was analyzed based. Combined with reduced scale model experiments, thermomechanical coupled finite element analysis integrated with recrystallization models of 316LN was performed to investigate RUE process. Metal flow, deformation distribution, recrystallization distribution, and extrusion load and clamping load in RUE process was analyzed. The experimental workpiece of pure lead based on reduced scale model validate metal flow behavior predicted by using numerical simulation. The results indicate that the essence of RUE process is to deflect the flow of the material around the orifice of the tube billet. The loads of dies are significantly sensitive to the initial forming temperature and the friction coefficient, while the impact of the extrusion velocity is negligible. RUE process could be used to form thick-walled tube structure with a nozzle, and it has a potential for solving the manufacture of AP1000 main pipe.

scholarly journals AN ANALYSIS OF SCALING METHODS FOR STRUCTURAL COMPONENTS IN THE CONTEXT OF SIZE EFFECTS AND NONLINEAR PHENOMENA

2020 ◽  
Vol 1 ◽  
pp. 797-806
Author(s):  
O. Altun ◽  
P. Wolniak ◽  
I. Mozgova ◽  
R. Lachmayer
Keyword(s):  
Size Effects ◽  
Scale Model ◽  
Nonlinear Phenomena ◽  
Component Size ◽  
Scaling Methods ◽  
System Properties ◽  
The Impact ◽  
Reduced Scale ◽  
Selection Of ◽  
Similitude Theory

AbstractSimilitude theory helps engineers to investigate system properties and behaviour with scaling methods. The application of such methods reduces the time for product development and production of prototypes. With increasing component size, the impact of size effects and nonlinear phenomena becomes more important in reduced scale model testing. The aim of this paper is to provide an overview of the scaling methods and their applicability with regard to size effects and nonlinear phenomena as well as a procedure to support the selection of a suitable method for the scaling task of structures.

Structural Analysis for a Reduced Scale Model of a Hydropower Plant Debris Containment Grid

2017 ◽  
Author(s):  
Felipe Santos de Castro ◽  
Eduardo Tadashi Katsuno ◽  
Andre Mitsuo Kogishi ◽  
José Marcos Paz de Souza ◽  
Joao Lucas Dozzi Dantas Dantas
Keyword(s):  
Structural Analysis ◽  
Hydropower Plant ◽  
Scale Model ◽  
Plant Debris ◽  
Reduced Scale

scholarly journals Benchmarking Quantum Computers and the Impact of Quantum Noise

2021 ◽  
Vol 54 (7) ◽  
pp. 1-35
Author(s):  
Salonik Resch ◽  
Ulya R. Karpuzcu
Keyword(s):  
Numerical Simulations ◽  
Computer Architecture ◽  
Quantum Noise ◽  
Computing System ◽  
Quantum Computers ◽  
Complicating Factors ◽  
The Impact

Benchmarking is how the performance of a computing system is determined. Surprisingly, even for classical computers this is not a straightforward process. One must choose the appropriate benchmark and metrics to extract meaningful results. Different benchmarks test the system in different ways, and each individual metric may or may not be of interest. Choosing the appropriate approach is tricky. The situation is even more open ended for quantum computers, where there is a wider range of hardware, fewer established guidelines, and additional complicating factors. Notably, quantum noise significantly impacts performance and is difficult to model accurately. Here, we discuss benchmarking of quantum computers from a computer architecture perspective and provide numerical simulations highlighting challenges that suggest caution.

scholarly journals The Impact of Initial Conditions in N-Body Simulations of Debris Discs

2015 ◽  
Vol 32 ◽  
Author(s):  
E. Thilliez ◽  
S. T. Maddison
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Parent Body ◽  
Dust Trapping ◽  
Physical Context ◽  
Disc Width ◽  
Wide Range ◽  
Belt Width ◽  
New Generation ◽  
The Impact

AbstractNumerical simulations are a crucial tool to understand the relationship between debris discs and planetary companions. As debris disc observations are now reaching unprecedented levels of precision over a wide range of wavelengths, an appropriate level of accuracy and consistency is required in numerical simulations to confidently interpret this new generation of observations. However, simulations throughout the literature have been conducted with various initial conditions often with little or no justification. In this paper, we aim to study the dependence on the initial conditions of N-body simulations modelling the interaction between a massive and eccentric planet on an exterior debris disc. To achieve this, we first classify three broad approaches used in the literature and provide some physical context for when each category should be used. We then run a series of N-body simulations, that include radiation forces acting on small grains, with varying initial conditions across the three categories. We test the influence of the initial parent body belt width, eccentricity, and alignment with the planet on the resulting debris disc structure and compare the final peak emission location, disc width and offset of synthetic disc images produced with a radiative transfer code. We also track the evolution of the forced eccentricity of the dust grains induced by the planet, as well as resonance dust trapping. We find that an initially broad parent body belt always results in a broader debris disc than an initially narrow parent body belt. While simulations with a parent body belt with low initial eccentricity (e ~ 0) and high initial eccentricity (0 < e < 0.3) resulted in similar broad discs, we find that purely secular forced initial conditions, where the initial disc eccentricity is set to the forced value and the disc is aligned with the planet, always result in a narrower disc. We conclude that broad debris discs can be modelled by using either a dynamically cold or dynamically warm parent belt, while in contrast eccentric narrow debris rings are reproduced using a secularly forced parent body belt.

A novel synergistic multi-scale modeling framework to predict micro- and meso-scale damage behaviors of 2D triaxially braided composite

2021 ◽  
pp. 105678952110339
Author(s):  
Hongyong Jiang ◽  
Yiru Ren ◽  
Qiduo Jin
Keyword(s):  
Compressive Load ◽  
Scale Model ◽  
Modeling Framework ◽  
Braided Composite ◽  
Multi Scale ◽  
Scale Modeling ◽  
Bridge Model ◽  
Multi Scale Modeling ◽  
Transverse Damage ◽  
Meso Scale

A novel synergistic multi-scale modeling framework with a coupling of micro- and meso-scale is proposed to predict damage behaviors of 2D-triaxially braided composite (2DTBC). Based on the Bridge model, the internal stress and micro damage of constituent materials are respectively coupled with the stress and damage of tow. The initial effective elastic properties of tow (IEEP) used as the predefined data are estimated by micro-mechanics models. Due to in-situ effects, stress concentration factor (SCF) is considered in the micro matrix, exhibiting progressive damage accumulation. Comparisons of IEEP and strengths between the Bridge and Chamis’ theory are conducted to validate the values of IEEP and SCF. Based on the representative volume element (RVE), the macro properties and damage modes of 2DTBC are predicted to be consistent with available experiments and meso-scale simulation. Both axial and transverse damage mechanisms of 2DTBC under tensile or compressive load are revealed. Micro fiber and matrix damage accumulations have significant effects on the meso-scale axial and transverse damage of tows due to multi-scale coupling effects. Different from existing meso-/multi-scale models, the proposed multi-scale model can capture a crucial phenomenon that the transverse damage of tow is vulnerable to micro fiber fracture. The proposed multi-scale framework provides a robust tool for future systematic studies on constituent materials level to larger-scale aeronautical materials.

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