Experimental and Numerical Study on the Robustness of Full-Scale Volumetric Steel Module under Sudden Support Removal Scenarios

Abstract Compared with the multipoint mooring fish cage, the single-point mooring (SPM) fish cage can spread out the fish wastes and uneaten feeds in a larger area, and it can also prevent the local environment from being overwhelmed. Thus, it has attracted much attention recently. In this research, different deformation-suppression methods are applied to the SPM system with a typical Norwegian fish cage aiming to increase the cultivation volume under the action of current and/or wave loads. A well-validated software, fhsim, is used to conduct the full-scale numerical study. The effects of the three deformation-suppression methods, i.e., (i) adding the lower bridles, (ii) adding the frontal rigid frame and (iii) adding the trawl doors, are analyzed under pure current and combined wave–current conditions. The results indicate that all the three deformation-suppression methods can improve the cultivation volume at least by 32% compared to the original SPM fish cage when the current velocity is larger than 0.5 m/s. In addition, moving the conjunction point close to the bottom ring can bring a positive effect on the cultivation volume maintaining with an only small increment in the tension force. This study can provide practical advice and useful guides for the SPM fish cage design.

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The influence of position of the post or its absence on the performance of the cable barrier system

MATEC Web of Conferences ◽

10.1051/matecconf/201821902012 ◽

2018 ◽

Vol 219 ◽

pp. 02012

Author(s):

Dawid Bruski ◽

Stanisław Burzyński ◽

Jacek Chróścielewski ◽

Łukasz Pachocki ◽

Krzysztof Wilde ◽

...

Keyword(s):

Numerical Simulations ◽

Road Safety ◽

Numerical Study ◽

Full Scale ◽

The Road ◽

Safety Barriers ◽

Study Results ◽

Crash Tests

Road safety barriers are used to increase safety in potentially dangerous places on the roads. They are designed and installed on the roads to prevent any vehicle from getting outside the travelled way or from entering the opposite lane of the road. Barriers, which are used on European roads, have to undergo full scale crash tests according to the EN 1317 standards. Nowadays as a supplement to real crash tests, numerical simulations are commonly used. The work concerns the influence of position of the post or its absence on the crashworthiness of the cable barrier based on numerical study results.

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A Hybrid BEM-CFD Virtual Blade Model to Predict Interactions between Tidal Stream Turbines under Wave Conditions

Journal of Marine Science and Engineering ◽

10.3390/jmse8120969 ◽

2020 ◽

Vol 8 (12) ◽

pp. 969

Author(s):

Nicolo’ Lombardi ◽

Stephanie Ordonez-Sanchez ◽

Stefania Zanforlin ◽

Cameron Johnstone

Keyword(s):

Numerical Study ◽

Experimental Tests ◽

Full Scale ◽

Small Scale ◽

Ansys Fluent ◽

Narrow Channels ◽

Tidal Turbine ◽

Performance Deterioration ◽

Set Up ◽

Blade Model

Tidal turbine array optimization is crucial for the further development of the marine sector. It has already been observed that tidal turbines within an array can be heavily affected by excessive aerodynamic interference, thus leading to performance deterioration. Small-scale experimental tests aimed at understanding the physical mechanisms of interaction and identifying optimal distances between machines can be found in the literature. However, often, the relatively narrow channels of laboratories imply high blockage ratios, which could affect the results, making them unreliable if extrapolated to full-scale cases. The main aim of this numerical study was to analyze the effects of the blockage caused by the laboratory channel walls in cases of current and also current surface waves. For this purpose, the performance predictions achieved for two turbines arranged in line for different lateral offsets in case of a typical laboratory scale were compared to the predictions obtained for a full scale, unconfined environment. The methodology consisted in the adoption a hybrid Blade Element Momentum–Computational Fluid Dynamics (BEM-CFD) approach, which was based on the Virtual Blade Model of ANSYS-Fluent. The results indicate that (1) the performance of a downstream turbine can increase up to 5% when this has a lateral separation of 1.5D from an upstream device in a full-scale environment compared to a misleading 15% calculated for the laboratory set-up, and (2) the relative fluctuations of power and thrust generated by waves are not significantly affected by the domain dimensions.

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Full-scale multi-ejector module for a carbon dioxide supermarket refrigeration system: Numerical study of performance evaluation

Energy Conversion and Management ◽

10.1016/j.enconman.2017.02.007 ◽

2017 ◽

Vol 138 ◽

pp. 312-326 ◽

Cited By ~ 36

Author(s):

Jakub Bodys ◽

Michal Palacz ◽

Michal Haida ◽

Jacek Smolka ◽

Andrzej J. Nowak ◽

...

Keyword(s):

Carbon Dioxide ◽

Performance Evaluation ◽

Numerical Study ◽

Full Scale ◽

Refrigeration System

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The Assessment of Residual Stress Effects on Ductile Tearing Using Continuum Damage Mechanics

Journal of Pressure Vessel Technology ◽

10.1115/1.2967876 ◽

2008 ◽

Vol 130 (4) ◽

Cited By ~ 3

Author(s):

Andrew H. Sherry ◽

Mark A. Wilkes ◽

John K. Sharples ◽

Peter J. Budden

Keyword(s):

Residual Stress ◽

Crack Growth ◽

Damage Mechanics ◽

Numerical Study ◽

Growth Behavior ◽

Full Scale ◽

Crack Growth Behavior ◽

Specimen Thickness ◽

Good Prediction ◽

Ductile Tearing

This paper presents the results of a numerical study undertaken to assess the influence of residual stresses on the ductile tearing behavior of a high strength low toughness aluminum alloy. The Gurson–Tvergaard model was calibrated against conventional fracture toughness data using parameters relating to void nucleation, growth, and coalescence. The calibrated model was used to predict the load versus ductile tearing behavior of a series of full-scale and quarter-scale wide-plate tests. These center-cracked tension tests included specimens that contained a self-balancing residual stress field that was tensile in the region of the through-wall crack. Analyses of the full-scale wide-plate tests indicated that the model provides a good prediction of the load versus the ductile tearing behavior up to approximately 3mm of stable tearing. The influence of residual stress on the load versus the crack growth behavior was accurately simulated. Predictions of the load versus the crack growth behavior of full-scale wide-plate tests for crack extensions greater than 3mm and of the quarter-scale tests were low in terms of predicted load at a given amount of tearing. This was considered to result from (i) the “valid” calibration range in terms of specimen thickness and crack extension, (ii) the development of shear lips, and (iii) the differences in the micromechanism of ductile void formation under plane strain and under plane stress conditions.

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Failure of X52 Wrinkled Pipelines Subjected to Monotonic Axial Deformation

Journal of Pressure Vessel Technology ◽

10.1115/1.2894294 ◽

2008 ◽

Vol 130 (2) ◽

Cited By ~ 2

Author(s):

Y. Zhang ◽

S. Das

Keyword(s):

Parametric Study ◽

Numerical Study ◽

Numerical Technique ◽

Small Diameter ◽

Full Scale ◽

Thickness Ratio ◽

Axial Deformation ◽

Cross Sectional ◽

Full Scale Tests ◽

Internal Pressures

This study was undertaken to investigate and understand the behavior of a wrinkled energy pipeline when subjected to sustained monotonic axial compressive deformation. This study involved both experimental and numerical investigations. Two full-scale laboratory tests with moderate and high internal pressures on X52 grade steel pipes with a diameter-to-thickness ratio of 45 show that this pipeline is extremely ductile and did not rupture under axisymmetric compressive axial deformation. However, they fail due to the excessive cross-sectional deformation and the final deformed shape looks like an accordion due to the formation of multiple wrinkles. Subsequently, a detailed parametric study using a numerical technique was undertaken to determine the failure condition and failure mode of this pipeline for various realistic internal pressures and diameter-to-thickness ratios. A nonlinear finite element method was used for the numerical study. The numerical model was validated with the data obtained from the two full-scale tests. The parametric study shows that the X52 linepipe loses its integrity due to the rupture in the pipe wall if the internal pressure is low and/or if the pipe has a small diameter-to-thickness ratio. This paper presents and discusses the results obtained both from the experimental and numerical parametric studies.

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Effect of the Pipe Joint on Structural Performance of a Single-span Greenhouse: A Full-scale Experimental and Numerical Study

Journal of Bio-Environment Control ◽

10.12791/ksbec.2021.30.4.410 ◽

2021 ◽

Vol 30 (4) ◽

pp. 410-418

Author(s):

Hyun Ho Shin ◽

Hee Ryong Ryu ◽

In Ho Yu ◽

Myeong Whan Cho ◽

Tae Cheol Seo ◽

...

Keyword(s):

Numerical Study ◽

Full Scale ◽

Structural Performance ◽

Pipe Joint

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Experimental and numerical study on fretting wear and fatigue of full-scale railway axles

Railway Engineering Science ◽

10.1007/s40534-020-00224-9 ◽

2020 ◽

Vol 28 (4) ◽

pp. 365-381

Author(s):

Lang Zou ◽

Dongfang Zeng ◽

Yabo Li ◽

Kai Yang ◽

Liantao Lu ◽

...

Keyword(s):

Fatigue Crack ◽

Stress Concentration ◽

Crack Initiation ◽

Numerical Study ◽

Equivalent Stress ◽

Fatigue Crack Initiation ◽

Fretting Fatigue ◽

Full Scale ◽

Fretting Wear ◽

Stress Intensity Factor Range

AbstractThis study investigated the fretting wear and fatigue of full-scale railway axles. Fatigue tests were conducted on full-scale railway axles, and the fretting wear and fretting fatigue in the fretted zone of the railway axles were analysed. Three-dimensional finite element models were established based on the experimental results. Then, multi-axial fatigue parameters and a linear elastic fracture mechanics-based approach were used to investigate the fretting fatigue crack initiation and propagation, respectively, in which the role of the fretting wear was taken into account. The experimental and simulated results showed that the fretted zone could be divided into zones I–III according to the surface damage morphologies. Fretting wear alleviated the stress concentration near the wheel seat edge and resulted in a new stress concentration near the worn/unworn boundary in zone II, which greatly promoted the fretting crack initiation at the inner side of the fretted zone. Meanwhile, the stress concentration also increased the equivalent stress intensity factor range ΔKeq below the mating surface, and thus promoted the propagation of fretting fatigue crack. Based on these findings, the effect of the stress redistribution resulting from fretting wear is suggested to be taken into account when evaluating the fretting fatigue in railway axles.

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