scholarly journals Substantiation of similitude rules of bending stiffness of twisted fishing gear

2020 ◽  
Vol 0 (1) ◽  
pp. 77-85
Author(s):  
Alexander Alekseevich Nedostup ◽  
Karina Konovalova ◽  
Pavel Nasenkov ◽  
Alexey Olegovich Razhev ◽  
Sergey Fedorov
Keyword(s):  
Physical Modeling ◽  
Large Scale ◽  
Large Diameter ◽  
Physical And Mechanical Properties ◽  
Bending Stiffness ◽  
Full Scale ◽  
Dynamic Processes ◽  
Fishing Gear ◽  
Commercial Fishery ◽  
Engineering Structures

The article considers the problems of physical modeling of twisted filamentary parts of fishing gear and the similitude rules of bending stiffness of filamentary gear parts (FP). The problems are caused firstly by the scope, high costs and complexity of engineering structures in commercial fishery, and thus it was impossible to use them in full-scale testing. Secondly, the lack of systematic experiments prevented from measuring the bending stiffness of synthetic rope parts of fishing gear (SRP). Thus, it becomes necessary to conduct model experiments related to physical modeling of dynamic processes occurring in twisted fishing gear, as well as to carry out a detailed study of the theory of similarity. An attempt to evaluate the bending stiffness of a full-scale object made of polyamide (diameter = 10 mm, the object length and pin diameter were found using large-scale physical characteristics) based on the analysis of experimental data on bending stiffness of synthetic filamentous gear parts made of polyamide with different diameter and length (length = 0.08; 0.10; 0.12; 0.16; 0.20, 0.24 m and diameter = 1.10; 2.0; 3.10; 4.0; 5.0, 6.0 mm) defined on the pins with diameter = 2.0, 10.0 and 30.0 mm. The obtained data will help to prove the correctness of using the theory of dynamic similarity in the course of justification of similarity rules of bending stiffness of the large-diameter cordage and to determine the basic physical and mechanical properties necessary for modeling industrial fishing gear.

scholarly journals Relativerigidity of twisted fishing gear

2020 ◽  
Vol 0 (1) ◽  
pp. 46-60
Author(s):  
Alexander Alekseevich Nedostup ◽  
Karina Konovalova ◽  
Pavel Nasenkov ◽  
Alexey Olegovich Razhev ◽  
Boris Altschul ◽  
...  
Keyword(s):  
Physical Modeling ◽  
Bending Stiffness ◽  
Full Scale ◽  
Torsional Stiffness ◽  
Dynamic Processes ◽  
Fishing Gear ◽  
Model Experiments ◽  
Longitudinal Stiffness ◽  
Longitudinal Bending ◽  
Dimensionless Combination

The article touches upon the problem of physical modeling of fishing twisted filamentary materials, in particular, the justification of the rules of similarity of relative longitudinal, bending and torsional stiffness of filamentary parts. The formulation of the problem is associated with the difficulties of conducting full-scale experiments for designing new fishing gear, as well as with the lack of systematic experiments on measuring the stiffness of synthetic cordage. In connection with this, it becomes necessary to conduct model experiments related to physical modeling of dynamic processes occurring with the cordage under load. There has been calculated the coefficient of proportionality of bending stiffness that determines the ability of filamentary parts and cordage to resist bending. There have been given the formulas that determine the combination of the ratio of bending stiffness to longitudinal stiffness and the dimensionless combination of the ratio of bend-ing stiffness to torsional stiffness. The study allows to predict the behavior and basic properties (di-ameter, density, strength, elongation, etc.) of modern synthetic filamentous fishing gear at the stage of their creation (design).

scholarly journals Substantiationofrules ofsimilarityofbreakingloadoftwistedfishinggear

2020 ◽  
Vol 0 (1) ◽  
pp. 38-45
Author(s):  
Alexander Alekseevich Nedostup ◽  
Pavel Nasenkov ◽  
Alexey Olegovich Razhev ◽  
Karina Konovalova ◽  
Sergey Fedorov
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Large Diameter ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Breaking Load ◽  
Full Scale ◽  
Fishing Gear ◽  
Scale Modeling ◽  
Polyamide Fibers

The article focuses on the problem of physical modeling of the physical and mechanical properties of fishing twisted filamentary materials, in particular, the most important one – the breaking load. The problems arise because of conducting full-scale experiments, particularly when the ropes of large diameter are used to build the rope parts of fishing gear. The solution to the problem of determining the breaking load on filamentary parts can be found by using specialized tensile testing machines and modern software, which is an effective tool for predicting the reliability and a resource of a gear part operating in difficult conditions of dynamic and shock loads. However, de-signing of fishing gear must begin with large-scale modeling, which will help to correctly calculate the physical and mechanical properties of the designed object using the well-known parameters of the full-scale material. The similarity rules of breaking load of fishing twisted filamentary gear used for the construction of industrial fishing tools will make it possible to model new elements of these tools without conducting full-scale experiments. At the same time, they will already contain solutions to problems associated with studying the dynamic processes, deformation, fracture, as well as the prediction of reliability and resource of the material. The technique proposed based on determining the scale of similarity of filamentary gear made of polyamide fibers, will help to simu-late various net and rope elements from filaments gear of various sizes and structures, instead of conducting energy-intensive experimental studies on ropes of large diameter.

Developments for in Situ Tests on Compacted Bentonite-Based Buffer Material

1990 ◽  
Vol 212 ◽  
Author(s):  
B. H. Kjartanson ◽  
M. N. Gray ◽  
B.C.M. Pulles
Keyword(s):  
Large Scale ◽  
Large Diameter ◽  
Full Scale ◽  
In Situ Tests ◽  
Buffer Material ◽  
In Situ Experiments ◽  
Buffer Mixture ◽  
Underground Research Laboratory ◽  
Nuclear Fuel Waste

ABSTRACTAECL Research is carrying out large-scale in situ experiments at its Underground Research Laboratory (URL). The Buffer/Container Experiment is designed principally to investigate the full scale, in situ performance of bentonite-based buffer material in a single emplacement borehole environment. In addition, the response of the rock to excavation and heating will be investigated. The experiment also allows for the development of the technologies needed to demonstrate some of the vault engineering activities proposed in the Canadian nuclear fuel waste disposal concept. These include excavation of large diameter boreholes for waste emplacement and in situ compaction of a bentonite/sand buffer mixture. Although these methodologies developed for the URL have not been optimized for the commercial, full-scale operations needed for a disposal vault, results show that the equipment and methodologies needed for vault operations are a reasonable extrapolation of existing technology.

Situational Breakdowns

2019 ◽  
Author(s):  
Anne Nassauer
Keyword(s):  
United States ◽  
Large Scale ◽  
Contextual Factors ◽  
The United States ◽  
Social Outcomes ◽  
Dynamic Processes ◽  
Collective Decisions ◽  
Different Types ◽  
The Impact

This book provides an account of how and why routine interactions break down and how such situational breakdowns lead to protest violence and other types of surprising social outcomes. It takes a close-up look at the dynamic processes of how situations unfold and compares their role to that of motivations, strategies, and other contextual factors. The book discusses factors that can draw us into violent situations and describes how and why we make uncommon individual and collective decisions. Covering different types of surprise outcomes from protest marches and uprisings turning violent to robbers failing to rob a store at gunpoint, it shows how unfolding situations can override our motivations and strategies and how emotions and culture, as well as rational thinking, still play a part in these events. The first chapters study protest violence in Germany and the United States from 1960 until 2010, taking a detailed look at what happens between the start of a protest and the eruption of violence or its peaceful conclusion. They compare the impact of such dynamics to the role of police strategies and culture, protesters’ claims and violent motivations, the black bloc and agents provocateurs. The analysis shows how violence is triggered, what determines its intensity, and which measures can avoid its outbreak. The book explores whether we find similar situational patterns leading to surprising outcomes in other types of small- and large-scale events: uprisings turning violent, such as Ferguson in 2014 and Baltimore in 2015, and failed armed store robberies.

Coupled Thermo-Hydro-Geochemical Models of Engineered Barrier Systems: The Febex Project

2000 ◽  
Vol 663 ◽  
Author(s):  
J. Samper ◽  
R. Juncosa ◽  
V. Navarro ◽  
J. Delgado ◽  
L. Montenegro ◽  
...  
Keyword(s):  
Large Scale ◽  
Reference Model ◽  
Numerical Models ◽  
Full Scale ◽  
Small Scale ◽  
Model Parameters ◽  
In Situ Test ◽  
Wide Range ◽  
Engineered Barrier

ABSTRACTFEBEX (Full-scale Engineered Barrier EXperiment) is a demonstration and research project dealing with the bentonite engineered barrier designed for sealing and containment of waste in a high level radioactive waste repository (HLWR). It includes two main experiments: an situ full-scale test performed at Grimsel (GTS) and a mock-up test operating since February 1997 at CIEMAT facilities in Madrid (Spain) [1,2,3]. One of the objectives of FEBEX is the development and testing of conceptual and numerical models for the thermal, hydrodynamic, and geochemical (THG) processes expected to take place in engineered clay barriers. A significant improvement in coupled THG modeling of the clay barrier has been achieved both in terms of a better understanding of THG processes and more sophisticated THG computer codes. The ability of these models to reproduce the observed THG patterns in a wide range of THG conditions enhances the confidence in their prediction capabilities. Numerical THG models of heating and hydration experiments performed on small-scale lab cells provide excellent results for temperatures, water inflow and final water content in the cells [3]. Calculated concentrations at the end of the experiments reproduce most of the patterns of measured data. In general, the fit of concentrations of dissolved species is better than that of exchanged cations. These models were later used to simulate the evolution of the large-scale experiments (in situ and mock-up). Some thermo-hydrodynamic hypotheses and bentonite parameters were slightly revised during TH calibration of the mock-up test. The results of the reference model reproduce simultaneously the observed water inflows and bentonite temperatures and relative humidities. Although the model is highly sensitive to one-at-a-time variations in model parameters, the possibility of parameter combinations leading to similar fits cannot be precluded. The TH model of the “in situ” test is based on the same bentonite TH parameters and assumptions as for the “mock-up” test. Granite parameters were slightly modified during the calibration process in order to reproduce the observed thermal and hydrodynamic evolution. The reference model captures properly relative humidities and temperatures in the bentonite [3]. It also reproduces the observed spatial distribution of water pressures and temperatures in the granite. Once calibrated the TH aspects of the model, predictions of the THG evolution of both tests were performed. Data from the dismantling of the in situ test, which is planned for the summer of 2001, will provide a unique opportunity to test and validate current THG models of the EBS.

So what's new? A survey of the education policies of orchestras and opera companies

1996 ◽  
Vol 13 (3) ◽  
pp. 259-270 ◽  
Author(s):  
Julia Winterson
Keyword(s):  
Large Scale ◽  
Full Scale ◽  
School Teachers ◽  
Education Policies ◽  
Art Galleries ◽  
High Profile ◽  
Creative Music ◽  
Direct Support

Originally, the creative music workshop involving professional players was intended to give direct support to school teachers and to enhance music in the classroom, but today's large-scale, high-profile projects mounted by orchestras and opera companies appear to be developing into a full-scale industry on their own. Their role in partnership with schools and colleges now requires clarification: a survey of education policies has revealed some confusion of aims with few bodies looking closely at objectives, outcomes and effects. Music companies could profit from the experience of museums and art galleries.

Destress blasting in deep mines of NorNickel’s Polar Division

2021 ◽  
pp. 32-36
Author(s):  
G. V. Sabyanin ◽  
S. Yu. Shilenko ◽  
A. V. Trofimov ◽  
A. P. Kirkin
Keyword(s):  
Horizontal Plane ◽  
Large Diameter ◽  
Geophysical Methods ◽  
Full Scale ◽  
Underground Mines ◽  
Destress Blasting ◽  
Drilling Cost ◽  
Full Scale Tests ◽  
Polar Division ◽  
Oktyabrsky Mine

Talnakh and Oktyabrsky ore fields are estimated as rockburst-hazardous starting from the depth of 700 m downward according to safety rules. This means that mining is only permitted within certain protected zones. At the present times, such protected zones are generated in underground mines by means of the large-diameter destressing drilling. Despite proved efficiency, the high cost and large amount of the destressing drilling are the grave faults of this approach. Aiming to save drilling cost, it is proposed to make rock mass rockburst-unhazardous using destress blasting. This article gives a brief description of the destress blasting mechanism. This method has been effectively used in relaxation of pillars from stresses before extraction of the reserves from the pillars both in Russia and abroad. In Oktyabrsky Mine stress relaxation of pillars was implemented by slotting, and the drilling and blasting data were available. This study proposes to destress rock masses by means of directional destress fracturing in horizontal plane through blasting of decked charges of special design. The initial parameters for destress blasting using holes with diameters of 76 and 130 mm are determined. The charge design aimed to ensure a zone of fractures in the horizontal plane, at minimized vertical fracturing is described. This information can be used in planning of full-scale tests to refine parameters and application ranges of the method. For the full-scale tests, it is suggested to undertake destress blasting at different blast patterns on different test sites, and to compare the results with the current destressing method (destressing drilling). Efficiency can be proved using geomechanical and geophysical methods. The authors appreciate participation of V. P. Marysyuk and T. P. Darbinyan from NorNickel’s Polar Division in this study.

Design of crack arrestors for ultra high grade gas transmission pipelines: simulation of crack initiation, propagation and arrest

2011 ◽  
Vol 2 (2) ◽  
pp. 307-319
Author(s):  
F. Van den Abeele ◽  
M. Di Biagio ◽  
L. Amlung
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Large Scale ◽  
Large Diameter ◽  
Pipe Material ◽  
High Grade ◽  
Gas Pipelines ◽  
Ductile Crack ◽  
Reinforced Plastics ◽  
Four Point Bending

One of the major challenges in the design of ultra high grade (X100) gas pipelines is the identification of areliable crack propagation strategy. Recent research results have shown that the newly developed highstrength and large diameter gas pipelines, when operated at severe conditions, may not be able to arrest arunning ductile crack through pipe material properties. Hence, the use of crack arrestors is required in thedesign of safe and reliable pipeline systems.A conventional crack arrestor can be a high toughness pipe insert, or a local joint with higher wall thickness.According to experimental results of full-scale burst tests, composite crack arrestors are one of the mostpromising technologies. Such crack arrestors are made of fibre reinforced plastics which provide the pipewith an additional hoop constraint. In this paper, numerical tools to simulate crack initiation, propagationand arrest in composite crack arrestors are introduced.First, the in-use behaviour of composite crack arrestors is evaluated by means of large scale tensile testsand four point bending experiments. The ability of different stress based orthotropic failure measures topredict the onset of material degradation is compared. Then, computational fracture mechanics is applied tosimulate ductile crack propagation in high pressure gas pipelines, and the corresponding crack growth inthe composite arrestor. The combination of numerical simulation and experimental research allows derivingdesign guidelines for composite crack arrestors.

Access and Logistics Challenges in Mountain Terrain Pipeline Projects

2014 ◽  
Author(s):  
Mark McDougall ◽  
Ken Williamson
Keyword(s):  
Construction Projects ◽  
Large Scale ◽  
Oil And Gas ◽  
Large Diameter ◽  
Gas Production ◽  
Additional Time ◽  
Oil And Gas Production ◽  
Road Design ◽  
Regulatory Constraints ◽  
The Right

Oil and gas production in Canada’s west has led to the need for a significant increase in pipeline capacity to reach export markets. Current proposals from major oil and gas transportation companies include numerous large diameter pipelines across the Rocky Mountains to port locations on the coast of British Columbia (BC), Canada. The large scale of these projects and the rugged terrain they cross lead to numerous challenges not typically faced with conventional cross-country pipelines across the plains. The logistics and access challenges faced by these mountain pipeline projects require significant pre-planning and assessment, to determine the timing, cost, regulatory and environmental impacts. The logistics of pipeline construction projects mainly encompasses the transportation of pipe and pipeline materials, construction equipment and supplies, and personnel from point of manufacture or point of supply to the right-of-way (ROW) or construction area. These logistics movement revolve around the available types of access routes and seasonal constraints. Pipeline contractors and logistics companies have vast experience in moving this type of large equipment, however regulatory constraints and environmental restrictions in some locations will lead to significant pre-planning, permitting and additional time and cost for material movement. In addition, seasonal constraints limit available transportation windows. The types of access vary greatly in mountain pipeline projects. In BC, the majority of off-highway roads and bridges were originally constructed for the forestry industry, which transports logs downhill whereas the pipeline industry transports large equipment and pipeline materials in both directions and specifically hauls pipe uphill. The capacity, current state and location of these off-highway roads must be assessed very early in the process to determine viability and/or potential options for construction access. Regulatory requirements, environmental restrictions, season of use restrictions and road design must all be considered when examining the use of or upgrade of existing access roads and bridges. These same restrictions are even more critical to the construction of new access roads and bridges. The logistics and access challenges facing the construction of large diameter mountain pipelines in Western Canada can be managed with proper and timely planning. The cost of the logistics and access required for construction of these proposed pipeline projects will typically be greater than for traditional pipelines, but the key constraint is the considerable time requirement to construct the required new access and pre-position the appropriate material to meet the construction schedule. The entire project team, including design engineers, construction and logistics planners, and material suppliers must be involved in the planning stages to ensure a cohesive strategy and schedule. This paper will present the typical challenges faced in access and logistics for large diameter mountain pipelines, and a process for developing a comprehensive plan for their execution.

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