scholarly journals Influence of polymer coatings on icing of ship structures

2021 ◽  
pp. 18-22
Author(s):  
С.И. Корягин ◽  
О.В. Шарков ◽  
Н.Л. Великанов
Keyword(s):  
Surface Roughness ◽  
Polymer Coatings ◽  
Ship Hull ◽  
Water Salinity ◽  
Ship Structures ◽  
Adhesive Compositions ◽  
Ship Repair ◽  
Environmental Temperatures ◽  
Ice Adhesion

Полимерные покрытия находят все более широкое применение в судостроении и судоремонте. Этому способствует многообразие полимерных покрытий с различными свойствами. Одним из распространённых требований, предъявляемым к корпусным конструкциям морских судов является необходимость обеспечения их безотказной работы в условиях воздействия отрицательных температур окружающей среды. При интенсификации процессов обледенения возможно возникновение аварийных ситуаций. В статье рассмотрены различные аспекты влияния полимерных покрытий на обледенение судовых корпусных конструкций. Приведены экспериментальные зависимости адгезии льда к металлу и полимерам от солености воды, от величины шероховатости. Установлено, что изменение шероховатости поверхностей и соленость воды существенно влияют на адгезию полимерных покрытий ко льду. Выявлены клеевые композиции, обеспечивающие полимерным покрытиям наименьшую адгезию ко льду. Исследования позволяют дать рекомендации по совершенствованию методов ремонта и модернизации судовых корпусных конструкций. Polymer coatings are increasingly used in shipbuilding and ship repair. This is facilitated by the variety of polymer coatings with different properties. One of the most common requirements for marine hull structures is the need to ensure their trouble-free operation under the influence of negative environmental temperatures. With the intensification of the processes of icing possible the occurrence of accidents. The article deals with various aspects of the influence of polymer coatings on the icing of ship hull structures. Experimental dependences of ice adhesion to metal and polymers on water salinity and roughness are presented. It was found that changes in surface roughness and water salinity significantly affect the adhesion of polymer coatings to ice. Adhesive compositions that provide polymer coatings with the lowest adhesion to ice are identified. The research makes it possible to give recommendations for improving the methods of repair and modernization of ship hull structures.

Calculation and Experimental Technique for Determining the Damping Properties of Composite Materials

2018 ◽  
Vol 938 ◽  
pp. 46-53 ◽  
Author(s):  
Sergey I. Koryagin ◽  
O.V. Sharkov ◽  
Nikolay L. Velikanov
Keyword(s):  
Experimental Technique ◽  
Polymer Coatings ◽  
Engineering Systems ◽  
Damping Properties ◽  
Metal Structures ◽  
Experimental Specimen ◽  
Adhesive Compositions ◽  
Improved Accuracy ◽  
Damping Capability

Polymer coatings are widely used for effective vibration damping of sheet or hull structures of different engineering systems. The article presents a calculation and experimental technique that enables improved accuracy and validity of damping properties determination of polymer coatings. Mathematical models to determine the parameters of the experimental specimen having a homogenous strain state of the polymer coating are obtained. Experimentally confirmed that the use of coatings based on adhesive compositions such as "Sprut" increases by 18...28 times the damping capability in metal structures. An addition of fillers in adhesive compositions "Sprut" type in a proportion of 30...50% of its weight reduces by 2.4 times the damping properties of metal structures.

scholarly journals Intrinsic dependence of ice adhesion strength on surface roughness

2020 ◽  
Vol 385 ◽  
pp. 125382 ◽  
Author(s):  
Halar Memon ◽  
Junpeng Liu ◽  
Davide S.A. De Focatiis ◽  
Kwing-so Choi ◽  
Xianghui Hou
Keyword(s):  
Surface Roughness ◽  
Adhesion Strength ◽  
Ice Adhesion

Analysis of Free and Forced Ship Vibrations Using Finite Element Method

2010 ◽  
Author(s):  
Adil Yucel ◽  
Alaeddin Arpaci
Keyword(s):  
Finite Element ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Free Vibration Analysis ◽  
Ship Hull ◽  
Mode Shapes ◽  
Ship Structures ◽  
Hull Structure ◽  
Forced Vibration Analysis ◽  
Ship Vibration

With the increase of ship size and speed, shipboard vibration becomes a great concern in the design and construction of the vessels. Excessive ship vibration is to be avoided for passenger comfort and crew habitability. In addition to undesired effects on humans, excessive ship vibration may result in the fatigue failure of local structural members or malfunction of machinery and equipment. The propeller induces fluctuating pressures on the surface of the hull, which induce vibration in the hull structure. These pressure pulses acting on the ship hull surface above the propeller as the predominant factor for vibrations of ship structures are taken as excitation forces for forced vibration analysis. Ship structures are complex and may be analyzed after idealization of the structure. Several simplifying assumptions are made in the finite element idealization of the hull structure. In this study, a three-dimensional finite element model representing the entire ship hull, including the deckhouse and machinery propulsion system, has been developed using a solid modeling software for local and global vibration analyses. Vibration analysis has been studied under two conditions which are free-free (dry) and in-water (wet). Wet analysis has been implemented using acoustic elements. The total damping associated with overall ship hull structure vibration has been considered as a combination of the several damping components. As the result of global ship free vibration analysis, global natural frequencies and mode shapes have been determined. Besides, responses of local ship structures have been determined as the result of propeller induced forced vibration analysis.

Effects of surface roughness and energy on ice adhesion strength

2011 ◽  
Vol 257 (8) ◽  
pp. 3786-3792 ◽  
Author(s):  
M. Zou ◽  
S. Beckford ◽  
R. Wei ◽  
C. Ellis ◽  
G. Hatton ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Adhesion Strength ◽  
Ice Adhesion

scholarly journals Comparative study on the influence of surface characteristics on de-icing evaluation

2021 ◽  
Author(s):  
Halar Memon ◽  
Kiana Mirshahidi ◽  
Kamran Alasvand Zarasvand ◽  
Kevin Golovin ◽  
Davide S. A. De Focatiis ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Comparative Study ◽  
Adhesion Strength ◽  
Partial Correlation ◽  
Contact Angle Hysteresis ◽  
Surface Characteristics ◽  
Evaluation Methods ◽  
Curvilinear Relationship ◽  
Ice Adhesion

AbstractA comparative study of de-icing evaluation methods was conducted in this work, and their variations in response to surface characteristics were investigated. The mechanical de-icing measurements include centrifugal, push, and tensile methods. The centrifugal and the horizontal push (shear) methods suggested a linear relationship of ice adhesion strength with surface roughness, whereas the tensile (normal) method indicated an inverse curvilinear relationship with contact angle hysteresis. A partial correlation of contact angle hysteresis on the shear-based methods was also indicated over a specified range of surface roughness. Further attempts were also made on 1H,1H,2H,2H-perfluorooctyltriethoxysilane-coated surfaces, and the ice adhesion indicated a clear reduction in the normal de-icing method, whereas the shear-based methods did not show a considerable change in ice adhesion, highlighting their mechanical forces-centric response. Lastly, a further evaluation using a hybrid de-icing method was conducted, to verify the influence of surface characteristics on ice removal involving heating, which demonstrated a partial correlation of energy consumption with the ice adhesion strength over a specified range of surface roughness. The results obtained in this study provide crucial information on the influence of surface characteristics on ice adhesion and offer material-dependent correlations of the popular de-icing evaluation methods. The conclusions could be applied to define an appropriate testing method for the evaluation of icephobic surfaces and coatings. Graphical abstract

scholarly journals Review of Ultimate Strength Assessment of Ageing and Damaged Ship Structures

2020 ◽  
Author(s):  
M. Tekgoz ◽  
Y. Garbatov ◽  
C. Guedes Soares
Keyword(s):  
Ultimate Strength ◽  
Load Capacity ◽  
Fatigue Cracking ◽  
Ship Hull ◽  
Structural Behaviour ◽  
Ship Structures ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
The Impact ◽  
Damaged Ship

AbstractThe objective of this work is to provide an overview of the ultimate strength assessment of ageing and damaged ship structures in the last decades. Particular attention is paid to the ultimate strength of plates, stiffened panels, box girders, and entire ship hull structures subjected to corrosion degradation, fatigue cracking, and mechanical damage caused by accidental loading or impact. A discussion on the effect of the cyclic load on the plate rigidity, re-yielding, and ultimate load capacity on the ship hull girder is also part of the present study. Finally, some conclusions and discussions about potential future work are provided, identifying that more studies about the impact of corrosion degradation on the structural behaviour of the stiffened panels and the overall hull girders are needed. Studies related to the dynamic collapse behaviour of corroded and damaged ship structures under time-variant load also requires additional attention.

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