scholarly journals Development of technology for electron beam welding of impellers of centrifugal pumps for ships and offshore structures operated in the Arctic

2021 ◽  
Vol 3 (397) ◽  
pp. 133-140
Author(s):  
V. Raskov ◽  
◽  
M. Sharapov ◽  
E. Blank ◽  
◽  
...  
Keyword(s):  
Technology Development ◽  
Electron Beam Welding ◽  
High Strength ◽  
Offshore Structures ◽  
The Arctic ◽  
Cover Plate ◽  
Centrifugal Pumps ◽  
Soldering Alloys ◽  
Centrifugal Equipment ◽  
Main Material

Object and purpose of research. Centrifugal equipment is widely used in various sectors of industry. One of the main part of centrifugal equipment is the impeller. Application of impellers in shipbuilding is a promising field, in particular for fail-free operation in harsh Arctic environment. The purpose of this study is development of manufacturing processes for impellers involving electro-beam welding (EBW) without soldering alloys and final thermal treatment. Materials and methods. The main material chosen for the impeller is the high-strength cold-resistant steel 10ХН3МД. Main results. In the process of technology development, the impeller design was chosen. Welding conditions were optimized on mock-up samples modeling the T-joint of cover plate with vane. Sample tests and investigation were done. Conclusions were made regarding the follow-on work and EBW introduction. Conclusion. EBW technology for manufacturing of impellers was developed making it possible to fabricate impellers of high-strength cold resistant materials, including difficult-to-weld materials.

Fiber element modeling of circular double-skin concrete-filled stainless-carbon steel tubular columns under axial load and bending

2022 ◽  
pp. 136943322110651
Author(s):  
Mizan Ahmed ◽  
Qing Quan Liang ◽  
Ahmed Hamoda
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
High Performance ◽  
Mechanical Performance ◽  
Axial Strain ◽  
High Strength ◽  
Offshore Structures ◽  
Numerical Results ◽  
Beam Columns ◽  
Double Skin

Circular concrete-filled double-skin steel tubular (CFDST) columns with external stainless-steel are high-performance composite columns that have potential applications in civil construction including the construction of offshore structures, bridge piers, and transmission towers. Reflecting the limited research performed on investigating their mechanical performance, this study develops a computationally efficient fiber model to simulate the responses of short and slender beam-columns accounting for the influences of material and geometric nonlinearities. Accurate material laws of stainless steel, carbon steel, and confined concrete are implemented in the mathematical modeling scheme developed. A new solution algorithm based on the Regula-Falsi method is developed to maintain the equilibrium condition. The independent test results of short and slender CFDST beam-column are utilized to validate the accuracy of the theoretical solutions. The influences of various column parameters are studied on the load-axial strain [Formula: see text] curves, load-lateral deflection [Formula: see text] curves, column strength curves, and interaction curves of CFDST columns. Design formulas are suggested for designing short and beam-columns and validated against the numerical results. The computational model is found to be capable of simulating the responses of CFDST short and slender columns reasonably well. Parametric studies show that the consideration of the concrete confinement is important for the accuracy of the prediction of their mechanical responses. Furthermore, high-strength concrete can be utilized to enhance their load-carrying capacity particularly for short and intermediate slender beam-columns. The strengths of CFDST columns computed by the suggested design model are in good agreement with the test and numerical results.

Parameter Sensitivity in Numerical Modelling of Ice-Structure Interaction With Cohesive Element Method

2016 ◽  
Author(s):  
Dianshi Feng ◽  
Sze Dai Pang ◽  
Jin Zhang
Keyword(s):  
Element Model ◽  
Offshore Structures ◽  
Parameter Sensitivity ◽  
The Arctic ◽  
Cohesive Element ◽  
Structure Interaction ◽  
Marine Structure ◽  
Ice Loads ◽  
The Stability ◽  
Element Method

The increasing marine activities in the Arctic has resulted in a growing demand for reliable structural designs in this region. Ice loads are a major concern to the designer of a marine structure in the arctic, and are often the principal factor that governs the structural design [Palmer and Croasdale, 2013]. With the rapid advancement in computational power, numerical method is becoming a useful tool for design of offshore structures subjected to ice actions. Cohesive element method (CEM), a method which has been widely utilized to simulate fracture in various materials ranging from metals to ceramics and composites as well as bi-material systems, has been recently applied to predict ice-structure interactions. Although it shows promising future for further applications, there are also some challenging issues like high mesh dependency, large variation in cohesive properties etc., yet to be resolved. In this study, a 3D finite element model with the use of CEM was developed in LS-DYNA for simulating ice-structure interaction. The stability of the model was investigated and a parameter sensitivity analysis was carried out for a better understanding of how each material parameter affects the simulation results.

Promising use of high-strength nitrogen steel for the ice belt of marine machinery operating in the extreme arctic conditions

2021 ◽  
pp. 229-237
Author(s):  
A. A. Deev ◽  
G. Yu. Kalinin ◽  
K. E. Sadkin
Keyword(s):  
Physical And Mechanical Properties ◽  
High Strength ◽  
The Arctic ◽  
Welded Steel ◽  
Corrosion Resistant ◽  
Critical Elements ◽  
Steel Sheets ◽  
Nitrogen Steel ◽  
Arctic Conditions ◽  
Clad Steel

This article shows the possibility of using high-strength nitrogen-containing corrosion-resistant steel grade 04Kh20N6G11M2AFB for the construction of critical elements and units of marine equipment operating at low temperatures, including the Arctic. The advantages of nitrogen-containing steel over clad steel AB2 + 08Kh18N10T always used in shipbuilding and welded steel of F500W category are considered. According to the assessment of testing of homogeneous nitrogen steel sheets, the level of its physical and mechanical properties exceeds the analogous parameters of traditional AB2 + 08Kh18N10T steels in a wide temperature range, up to –90°C.

Design Under Arctic Conditions: A Summary of the Arctic Materials Project Guideline

2018 ◽  
Author(s):  
Agnes Marie Horn ◽  
Erling Østby ◽  
Odd Akselsen ◽  
Mons Hauge
Keyword(s):  
Cost Effective ◽  
Offshore Structures ◽  
International Standards ◽  
Hydrocarbon Exploration ◽  
Thickness Effect ◽  
The Arctic ◽  
Structural Elements ◽  
Practical Applications ◽  
Arctic Materials ◽  
Offshore Industry

The main goal of the 10 years Arctic Materials KMB project run by SINTEF (2008–2017) and supported by the industry is to establish criteria and solutions for safe and cost-effective application of materials for hydrocarbon exploration and production in arctic regions. The objective of the arctic materials project guideline (PG) is to assist designers to ensure safe and robust, yet cost-effective, design of offshore structures and structural elements in arctic areas through adequate material testing and requirements to material toughness. It is well known that when the temperature decreases, steel becomes more brittle. To prevent brittle fracture in the Arctic, the structure needs adequate toughness for the loading seen at low temperatures. None of the common offshore design codes today consistently address low temperature applications. In this respect, arctic areas are defined as minimum design temperatures below what current international standards have considered per today, i.e. −10 °C to −14°C. For practical applications, the PG defines arctic areas as minimum design temperature lower than −10 °C. It is acknowledging that design standards to a certain degree are based on operational and qualitative experiences gained by the offshore industry since the 1970’s. However, for arctic offshore facilities, limited operational experiences are gained by the industry. The basis of the guideline is that safe and robust design of structures and structural elements are ensured by combining standard industry practice today with learnings and findings from the 10 years Arctic Materials project. This paper is concerned with the rationale behind the material and test requirements provided in the arctic material guideline. The material requirements will be discussed in detail with emphasis on toughness requirement, constraint effect, thickness effect, acceptance criteria and material qualification criteria.

scholarly journals Fracture and its Role in Determining Ice Forces on Offshore Structures

1983 ◽  
Vol 4 ◽  
pp. 216-221 ◽  
Author(s):  
A.C. Palmer ◽  
D. J. Goodman ◽  
M. F. Ashby ◽  
A. G. Evans ◽  
J.W. Hutchinson ◽  
...  
Keyword(s):  
Deformation Mode ◽  
Theoretical Models ◽  
Offshore Structures ◽  
The Arctic ◽  
Theoretical Treatment ◽  
Strain Rates ◽  
Natural Processes ◽  
Design Loads ◽  
Ice Forces ◽  
Fracture Processes

One of the most conspicuous phenomena in the Arctic Is the fracture of sea ice. It is scarcely possible to travel far without seeing a variety of fracture forms, produced both by natural processes and by human activity.At strain-rates below about 10−4s−1, deformation is dominated by creep, but at higher strain-rates fracture is much more important. One of the reasons for this is the very low fracture toughness of ice. The movements of ice in contact with offshore structures often induce strain-rates well beyond the level at which fracture begins, and so offshore structures will often operate in the fracture regime, and it is fracture processes which will determine the design loads. We consider the different modes of repeated fracture that will occur, and classify them into distinct mechanisms of crushing, spalling, and radial and circumferential cracking. Experimental and field observations are plotted on a deformation mode map. A theoretical treatment of radial cracking confirms that very low loads can propagate cracks to long distances; these loads are small by comparison with those calculated from theoretical models that treat ice as a plastically-deforming continuum.

scholarly journals Forecasting of Technology Development of the Arctic Hydrocarbon Resources’ Extraction

2020 ◽  
Vol 162 ◽  
pp. 01008
Author(s):  
Tatiana Chvileva
Keyword(s):  
Oil And Gas ◽  
Technology Development ◽  
Arctic Region ◽  
Oil And Gas Industry ◽  
Integrated Approach ◽  
The Arctic ◽  
Gas Industry ◽  
Industrial Systems ◽  
Technological Forecasting ◽  
Energy Needs

The Arctic region has a great potential in development of hydrocarbon resources and can play an important role in meeting future global energy needs. In the presented work the specific features of the Arctic hydrocarbon projects are identified. Key needs of oil and gas industry in technology development within the framework of projects of extraction of hydrocarbon resources in the Arctic are revealed. A critical analysis of technological forecasting methods is presented. Problems and prospects of their use in the conditions of the Arctic zones are established. The need for an integrated approach to forecasting the development of industrial systems of the Arctic zone is justified.

New Approaches for Improved Efficiency and Flexibility in Process Chains of Press Hardening

2015 ◽  
Author(s):  
Dirk Landgrebe ◽  
Julia Schönherr ◽  
Norbert Pierschel ◽  
Stefan Polster ◽  
Andre Mosel ◽  
...  
Keyword(s):  
High Speed ◽  
Technology Development ◽  
Lightweight Design ◽  
High Strength ◽  
Press Hardening ◽  
High Speed Impact ◽  
Contact Heating ◽  
Process Chains ◽  
Impact Cutting ◽  
Significant Research

In the last decade, press hardening has become a fully established technology in both science and industry for the production of ultra-high-strength structural components, especially in the automotive industry. Beside the improvement of car performance such as safety and lightweight design, the production process is also one focus of trends in technology development in the field of press hardening. This paper presents an overview about alternative approaches for optimized process chains of press hardening, also including pre- and post-processing in addition to the actual forming and quenching process. Investigations on direct contact heating technology show new prospects regarding fast and flexible austenitization of blanks at compact device dimensions. By applying high speed impact cutting (HSIC) for trimming of press hardened parts, an alternative technology is available to substitute the slow and energy-intensive laser trimming in today’s press hardening lines. Combined with stroke-to-stroke control based on measuring of process-relevant parameters, a readjustment of the production line is possible in order to produce each part with individual, optimal process parameters to realize zero defect production of property-graded press hardened components with constant high part quality. Significant research in the field of press hardening was carried out at Fraunhofer Institute for Machine Tools and Forming Technology IWU, in the hot forming model process chain which enables the running of experiments under conditions similar to industrial scales. All practical tests were prepared by design of experiments and assisted by thermo-mechanical FE simulations.

Technical ceramics: material science and technology principles and mechanisms for the development and implementation of ceramic electrical insulators for various scientific and practical purposes

2020 ◽  
pp. 16-24
Author(s):  
O. V. Roman ◽  
V. T. Shmuradko ◽  
F. I. Panteleenko ◽  
O. P. Reut ◽  
T. I. Bendik ◽  
...  
Keyword(s):  
Materials Science ◽  
Electron Beam Welding ◽  
Raw Materials ◽  
High Strength ◽  
Technical Ceramics ◽  
Copper Aluminum ◽  
Scientific Practical ◽  
Electrical Insulation Materials ◽  
Electrical Materials ◽  
Physical And Chemical

The concept of creating electrical insulating ceramic materialsproducts from powder systems representing oxide and nonoxide chemical compounds was formed; a program document for materials science and technological logistics of physical and chemical transformation of technogenic mineral raw materials into electrical materials-products of various scientific, practical and specific technological purposes was created and implemented. The principal theoretical approach and its appliedpractical aspects of the development - research - creation of thermo- and chemically resistant structural electrical insulation materials - products for various scientific and practical purposes: automatic contact welding of tubular bimetals (for example, copper - aluminum), electron beam welding in vacuum of thickwalled large-sized structures made of high-strength aluminum alloys, high-temperature (1050 oC) hardening of drilling tools in vacuum furnaces in the medium of dissociated acetylene are considered, in electric transmissions of brake installations of quarry dump trucks (k/s) BelAZ.

scholarly journals Thermal Protection and Microclimate of SOLAS Approved Lifeboats

2010 ◽  
Author(s):  
Lawrence Mak ◽  
Andrew Kuczora ◽  
Brian Farnworth ◽  
Rob Brown ◽  
Michel B. DuCharme
Keyword(s):  
Thermal Resistance ◽  
Thermal Protection ◽  
Heat Rate ◽  
Offshore Structures ◽  
Ventilation Rate ◽  
The Arctic ◽  
Thermal Manikin ◽  
High Concentration ◽  
Marine Vehicles ◽  
Heat And Cold Stress

Lifeboats are used as an evacuation system on a wide variety of offshore structures and marine vehicles. Currently, International Maritime Organization (IMO) Lifesaving Appliances (LSA) Code does not specify thermal protection and ventilation criteria for lifeboats. A test program was conducted to assess the system thermal protection and microclimate of SOLAS approved lifeboats for the Arctic environment. Some of the research findings of the first phase experiments are reported in this paper. In conducting experiments with a 72-person SOLAS approved lifeboat, the study found that the lifeboat only had a ventilation rate of 2 litres per second with vents open only, which may not be adequate. Inadequate ventilation will result in high concentration of carbon dioxide, causing headache, dizziness, restlessness, breathing difficulty, sweating, and increased heat rate, cardiac output and blood pressure. All of these may adversely affect lifeboat occupants in performing survival tasks. Using a thermal manikin, only slight decrease in thermal resistance (less than 10%) was observed in many test cases, when active ventilation was implemented (ventilation rate of 31 and 42 litres per second) and when side hatches were opened (ventilation rate of 95 litres per second). This suggests that reasonable increase in ventilation rate may be implemented without trading off much in thermal protection. However, a more noticeable decreases in thermal resistance (15% to over 30%) were observed when clothing was wet. This suggests it is critical to stay dry. A mathematical model was also developed to assess heat and cold stress of lifeboat occupants under different environment, lifeboat, occupant and ventilation conditions.

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