A study of the development of a new type of bulb bracket for offshore structures using suitable casting steel

2010 ◽  
Author(s):  
Tae-Won Kim ◽  
Chung-Gil Kang ◽  
Sang-Sik Park ◽  
F. Barlat ◽  
Y. H. Moon ◽  
...  
Keyword(s):  
Offshore Structures ◽  
New Type ◽  
Casting Steel

scholarly journals Properties of Ambient-Cured Normal and Heavyweight Geopolymer Concrete Exposed to High Temperatures

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 740 ◽  
Author(s):  
Farhad Aslani ◽  
Zohaib Asif
Keyword(s):  
Mass Loss ◽  
High Temperatures ◽  
Offshore Structures ◽  
Normal Weight ◽  
Geopolymer Concrete ◽  
Coarse Aggregates ◽  
Residual Properties ◽  
New Type ◽  
Heavyweight Concrete ◽  
Underwater Structures

Ambient-cured heavyweight geopolymer concrete (HWGC) is a new type of concrete that combines the benefits of both heavyweight concrete (HWC) and geopolymer concrete (GC). HWGC provides proper protection from the sources that emit harmful radiations in medical and nuclear industries. Furthermore, HWGC may also be used in offshore structures for pipeline ballasting and similar underwater structures. In this study, heavyweight aggregates (magnetite) have been used and replaced by normal-weight coarse aggregates in GC at volume ratios of 50, 75, and 100% to attain heavyweight classification according to British standards. This study investigates the impacts of high temperatures on standard ambient-cured geopolymer concrete and ambient-cured HWGC through its residual properties regarding compressive and tensile strengths, mass loss, spalling intensity, and flexural strength. The residual properties were examined by heating 100 × 200 mm cylinder specimens to 100, 300, 600, and 900 °C. The results indicated that the maximum compressive strengths of 40.1 and 39.0 MPa were achieved by HWGC at 300 and 100 °C, respectively. The overall result shows that the strength of HWGC increases by increasing magnetite aggregate proportion, while the mass loss, intensity of spalling, and loss of strengths is proportional to temperature after a certain point. Minor spalling with holes and cracking was observed only at 900 °C in HWGC.

scholarly journals A Study on the Low Temperature & High-strength Low-alloy Material for Casting Steel of the Offshore Structures

2008 ◽  
Vol 45 (4) ◽  
pp. 426-431
Author(s):  
Soo-Ho Lee ◽  
Ki-Hyoung Han ◽  
Jae-Ryu Bae ◽  
Tae-Won Kim ◽  
Sang-Sik Park ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Strength ◽  
Offshore Structures ◽  
Alloy Material ◽  
Casting Steel

A Study on the Failure Mechanism of Suction Caisson under Vertical Load

2012 ◽  
Vol 256-259 ◽  
pp. 1985-1989
Author(s):  
Shu Cheng Jin ◽  
Yong Tao Zhang ◽  
Qi He Wu
Keyword(s):  
Bearing Capacity ◽  
Failure Mechanism ◽  
Offshore Structures ◽  
Engineering Practice ◽  
Vertical Load ◽  
Suction Caisson ◽  
Methods Of Evaluation ◽  
New Type ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

As a new type of deep water offshore foundation, suction caisson is widely used to offshore structures. However, the current methods of evaluation and design cannot meet the increasing requirement of engineering practice. In this dissertation, the studies are emphasized on finite element method for analyzing the suction caisson bearing capacity behavior and the failure mechanism under the vertical load. Based on studying the vertical bearing behavior of caissons with different ratio of length to diameter L / D, it shown that as L / D increases, the vertical bearing capacity growth slowed.

Fatigue and quasi-static analysis of a new type of surface preparation used for the CFRP repair of steel offshore structures

2018 ◽  
Vol 95 (9) ◽  
pp. 849-873 ◽  
Author(s):  
Valber Azevedo Perrut ◽  
Luiz Cláudio de Marco Meniconi ◽  
Eduardo Martins Sampaio ◽  
Ney Robson Ferreira Rohem ◽  
Marysilvia Ferreira da Costa
Keyword(s):  
Static Analysis ◽  
Surface Preparation ◽  
Offshore Structures ◽  
New Type

Use of a new type of anchor piles for stability of offshore structures

2007 ◽  
Vol 41 (3) ◽  
pp. 134-138
Author(s):  
V. N. Zhilenkov ◽  
S. A. Sosnina
Keyword(s):  
Offshore Structures ◽  
New Type

scholarly journals Penetration and Pullout Capacity of Low-Skirted Suction Caissons

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Mingyuan Wang ◽  
Xiaoke Liu ◽  
Xinglei Cheng ◽  
Qun Lu ◽  
Jiaqing Lu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Limit Equilibrium ◽  
Offshore Structures ◽  
Pullout Capacity ◽  
Soil Plug ◽  
Suction Caisson ◽  
Element Simulation ◽  
New Type ◽  
New Formula ◽  
Suction Caissons

The bearing capacity of suction caissons is the key to the design of offshore structures. A new type of cross-shaped low-skirted suction caisson is invented to effectively improve the bearing capacity, considering inevitable “soil plug” phenomenon. The behaviors of penetration and pullout for new low-skirted suction caisson are investigated by performing model tests. A new formula for calculating the penetration resistance is suggested based on the limit equilibrium theory and the test data, which can consider the change of the lateral area of the suction caisson during penetration. The behaviors of low-skirted suction caisson under inclined loading are analyzed by carrying out finite element simulation. The effects of loading angles and loading positions on the ultimate bearing capacity and failure mechanism of low-skirted suction caissons are discussed. The research results can provide a reference for the design of suction bucket foundation for offshore structures.

The Microstructure of Shock-Synthesized Diamond

1967 ◽  
Vol 25 ◽  
pp. 324-325
Author(s):  
Lucien F. Trueb
Keyword(s):  
Single Crystals ◽  
Preferred Orientation ◽  
High Magnification ◽  
Texture Pattern ◽  
Shock Process ◽  
New Type ◽  
Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

New type electron gun with electrostatic and electromagnetic lenses

1978 ◽  
Vol 36 (1) ◽  
pp. 62-63
Author(s):  
T. Ichinokawa ◽  
H. Maeda
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Optimum Condition ◽  
Bias Voltage ◽  
Electron Gun ◽  
Charge Effect ◽  
Micro Fabrication ◽  
Maximum Brightness ◽  
New Type ◽  
The Ideal

I. IntroductionThermionic electron gun with the Wehnelt grid is popularly used in the electron microscopy and electron beam micro-fabrication. It is well known that this gun could get the ideal brightness caluculated from the Lengumier and Richardson equations under the optimum condition. However, the design and ajustment to the optimum condition is not so easy. The gun has following properties with respect to the Wehnelt bias; (1) The maximum brightness is got only in the optimum bias. (2) In the larger bias than the optimum, the brightness decreases with increasing the bias voltage on account of the space charge effect. (3) In the smaller bias than the optimum, the brightness decreases with bias voltage on account of spreading of the cross over spot due to the aberrations of the electrostatic immersion lens.In the present experiment, a new type electron gun with the electrostatic and electromagnetic lens is designed, and its properties are examined experimentally.

A new type of defect structure in 124-superconducting oxide revealed by HREM

1991 ◽  
Vol 49 ◽  
pp. 1092-1093
Author(s):  
R. Sharma ◽  
B.L. Ramakrishna ◽  
N.N. Thadhani ◽  
D. Hianes ◽  
Z. Iqbal
Keyword(s):  
Shock Wave ◽  
Defect Structure ◽  
Neutron Radiation ◽  
Weak Links ◽  
Defect Structures ◽  
New Materials ◽  
New Type ◽  
Current Densities ◽  
Processing Techniques ◽  
Microstructural Studies

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.

ESEM - A multipurpose surface Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 632-633 ◽  
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Environmental Scanning ◽  
Gas Composition ◽  
Saturated Water Vapor ◽  
Surface Electron ◽  
Current State ◽  
Saturated Water ◽  
New Type ◽  
Temperature And Pressure

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.

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