scholarly journals Controlling parameter for wave types of long flexible cable undergoing vortex-induced vibration

2010 ◽  
Vol 4 ◽  
pp. 161-170 ◽  
Author(s):  
Liwu Zhang ◽  
Weimin Chen ◽  
Zhongqin Zheng
Keyword(s):  
Vortex Induced Vibration ◽  
Flexible Cable ◽  
Controlling Parameter

scholarly journals Controlling Parameter for Wave Types of Long Flexible Riser Undergoing Vortex-Induced Vibration

2010 ◽  
Author(s):  
Liwu Zhang ◽  
Weimin Chen
Keyword(s):  
Aspect Ratio ◽  
Numerical Simulations ◽  
Dimensional Analysis ◽  
Wide Band ◽  
Mode Competition ◽  
Vortex Induced Vibration ◽  
Mining Depth ◽  
Controlling Parameter ◽  
Fluid Damping ◽  
And Function

The aspect ratio of slender underwater structures of deep sea platforms such as riser, oil pipelines, tension legs and anchor chains increases with the mining depth increasing, the values of which often approach to 103 order. Investigation results in recent years show that the vortex-induced vibration of the flexible marine risers with large aspect ratio reveals some new phenomena, for example, the vortex-induced wave, multi-mode competition, wide band random vibration, which have brought new challenges to the study of vortex-induced vibration of long flexible risers. In this paper, the dimensionless parameter controlling the wave types of dynamic response of slender risers undergoing vortex-induced vibration is investigated by means of dimensional analysis and finite element numerical simulations (MSC Nastran). Our results indicate that there are three types of response for a slender riser, i.e. standing wave vibration, traveling wave vibration and intermediate state. Based on dimensional analysis the controlling parameter is found to be related to the system damping including fluid damping and structural damping, order number of the locked-in modes and the aspect ratio of riser. Furthermore through numerical simulations and function fitting, the expression and the critical value of the controlling parameter is presented. At last the physical meaning of the parameter is analyzed and discussed.

Experimental Investigation of Vortex Induced Vibration of Cross Flow Response for a Flexible Cable Under Uniform Current

2020 ◽  
Author(s):  
Prethiv Kumar R ◽  
S. Nallayarasu
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Strouhal Number ◽  
Lateral Displacement ◽  
Lift Coefficient ◽  
Strain Gauges ◽  
Vortex Induced Vibration ◽  
Flexible Cable ◽  
Wide Range ◽  
Uniform Current

Abstract Vortex Induced Vibration (VIV) of slender cylindrical structures subjected to uniform flow is subject interest since the use of such elements is common in the offshore and naval industry. The numerical and experimental investigation of VIV for slender, flexible cable member in uniform current has been carried out in this study. The experiments were conducted in a towing tank of 85 m length and 2.8 m water depth mounted with the facility to control speed, The carriage has a range of velocity up to 5 m/s. A flexible cable of diameter 15 mm with an aspect ratio of approximately 100 has been used for the present study. The lateral displacement of cable has been measured using the strain gauges mounted along the length. The strain gauges measure the axial strain due to lateral bending of the cable and in turn, converted to lateral displacement. Experiments were carried out for a wide range of Reynolds number (Re) ranging from 3000 to 15000. From the measured responses, the Strouhal number (St) is back calculated. It is observed that the Strouhal number for flexible cable ranges from 0.13 to 0.17 for low Reynolds number from 3000 to 15000 and it falls within the expected range. The normalized RMS displacements (RMS A/D) have been obtained for specified range of Re. The lift coefficient (CL) attains a stable value of around 0.10 to 0.25 for reduced velocity (Vr) greater than 5.33 for different locations. The lift coefficient follows a similar trend along the span for different Vr. Numerical simulation has been carried out using Shear7 software with results matching reasonably well.

Quantitative Electrical Analysis of FIB Prepared Vias on BiCMOS and CMOS090 Designs

2006 ◽  
Author(s):  
B. Domengès ◽  
P. Poirier
Keyword(s):  
Ion Beam ◽  
Beam Current ◽  
Kelvin Probe ◽  
Metal Line ◽  
Cross Sectional ◽  
Probe Technique ◽  
Cross Sectional Analysis ◽  
Controlling Parameter ◽  
Electrical Analysis ◽  
Sectional Analysis

Abstract In this study, the resistance of FIB prepared vias was characterized by the Kelvin probe technique and their physical characteristics studied using cross-sectional analysis. Two domains of resistivity were isolated in relation to the ion beam current used for the deposition of the via metal (Pt). Also submicrometer vias were investigated on 4.2 µm deep metal lines of a BiCMOS aluminum based design and a CMOS 090 copper based one. It is shown that the controlling parameter is the shape and volume of the contact, and that the contact formation is favored by the amount of over-mill of the via into the metal line it will contact.

Physical modeling and deformation simulation of flexible cable under the plane constraint

2017 ◽  
Vol 50 (4-6) ◽  
pp. 471-484
Author(s):  
Hongwang DU ◽  
Wei XIONG ◽  
Haitao WANG ◽  
Zuwen WANG
Keyword(s):  
Physical Modeling ◽  
Flexible Cable ◽  
Deformation Simulation

To the question of creating a complex mathematical model of a production system

2020 ◽  
Keyword(s):  
Mathematical Model ◽  
Hierarchical Structure ◽  
Production System ◽  
Quality Criterion ◽  
Controlling Parameter ◽  
Complex Mathematical Model

One of the approaches to the development of a complex mathematical model of a production system is considered. Keywords mathematical model; target subsystem; quality criterion; controlling parameter; hierarchical structure

Surface roughness effect on cylinder vortex-induced vibration at moderate Re regimes

2021 ◽  
Vol 224 ◽  
pp. 108690
Author(s):  
Xiangxi Han ◽  
Youhong Tang ◽  
Zhanbin Meng ◽  
Fei Fu ◽  
Ang Qiu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Roughness Effect ◽  
Vortex Induced Vibration

Research on sports aided teaching and training decision system oriented to deep convolutional neural network

2021 ◽  
pp. 1-15
Author(s):  
Qinyu Mei ◽  
Ming Li
Keyword(s):  
Neural Network ◽  
Decision Making ◽  
Control System ◽  
Convolutional Neural Network ◽  
Force Control ◽  
Control Experiment ◽  
Deep Convolutional Neural Network ◽  
Flexible Cable ◽  
Cable Force ◽  
And Training

Aiming at the construction of the decision-making system for sports-assisted teaching and training, this article first gives a deep convolutional neural network model for sports-assisted teaching and training decision-making. Subsequently, In order to meet the needs of athletes to assist in physical exercise, a squat training robot is built using a self-developed modular flexible cable drive unit, and its control system is designed to assist athletes in squatting training in sports. First, the human squat training mechanism is analyzed, and the overall structure of the robot is determined; second, the robot force servo control strategy is designed, including the flexible cable traction force planning link, the lateral force compensation link and the establishment of a single flexible cable passive force controller; In order to verify the effect of robot training, a single flexible cable force control experiment and a man-machine squat training experiment were carried out. In the single flexible cable force control experiment, the suppression effect of excess force reached more than 50%. In the squat experiment under 200 N, the standard deviation of the system loading force is 7.52 N, and the dynamic accuracy is above 90.2%. Experimental results show that the robot has a reasonable configuration, small footprint, stable control system, high loading accuracy, and can assist in squat training in physical education.

scholarly journals Hybrid Multisite Silicon Neural Probe with Integrated Flexible Connector for Interchangeable Packaging

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2605
Author(s):  
Ashley Novais ◽  
Carlos Calaza ◽  
José Fernandes ◽  
Helder Fonseca ◽  
Patricia Monteiro ◽  
...  
Keyword(s):  
Fabrication Process ◽  
High Signal ◽  
Wafer Level ◽  
Neural Probes ◽  
Insertion Force ◽  
Precise Integration ◽  
Flexible Cable ◽  
Flexible Polymer ◽  
Hybrid Silicon

Multisite neural probes are a fundamental tool to study brain function. Hybrid silicon/polymer neural probes combine rigid silicon and flexible polymer parts into one single device and allow, for example, the precise integration of complex probe geometries, such as multishank designs, with flexible biocompatible cabling. Despite these advantages and benefiting from highly reproducible fabrication methods on both silicon and polymer substrates, they have not been widely available. This paper presents the development, fabrication, characterization, and in vivo electrophysiological assessment of a hybrid multisite multishank silicon probe with a monolithically integrated polyimide flexible interconnect cable. The fabrication process was optimized at wafer level, and several neural probes with 64 gold electrode sites equally distributed along 8 shanks with an integrated 8 µm thick highly flexible polyimide interconnect cable were produced. The monolithic integration of the polyimide cable in the same fabrication process removed the necessity of the postfabrication bonding of the cable to the probe. This is the highest electrode site density and thinnest flexible cable ever reported for a hybrid silicon/polymer probe. Additionally, to avoid the time-consuming bonding of the probe to definitive packaging, the flexible cable was designed to terminate in a connector pad that can mate with commercial zero-insertion force (ZIF) connectors for electronics interfacing. This allows great experimental flexibility because interchangeable packaging can be used according to experimental demands. High-density distributed in vivo electrophysiological recordings were obtained from the hybrid neural probes with low intrinsic noise and high signal-to-noise ratio (SNR).

External suction-blowing method for controlling vortex-induced vibration of a bridge

2021 ◽  
Vol 215 ◽  
pp. 104661
Author(s):  
Zhicheng Xue ◽  
Bin Han ◽  
Hongfu Zhang ◽  
Dabo Xin ◽  
Jian Zhan ◽  
...  
Keyword(s):  
Vortex Induced Vibration
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