Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "marine structure" wg kryterium: Temat


Tytuł:
Design and mechanical analysis of a composite T-type connection structure for marine structures
Autorzy:
Li, Xiaowen
Zhu, Zhaoyi
Li, Yan
Hu, Zhe
Tematy:
T-type connection structure
composite structure design
test
mechanical analysis
marine structure
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:
https://bibliotekanauki.pl/articles/260625.pdf  Link otwiera się w nowym oknie
Opis:
A new T-type connection structure consisting of composite sandwich plates, reinforced cores and adhesive was proposed for the construction of lightweight ships to resolve connection problems between bulkheads and decks of composite lightweight ship superstructures. Based on the design principles and mechanical properties of composite structures, the mechanical behaviour of the structure under a dangerous loading condition was investigated. In addition, the ultimate bearing capacities and damage modes were examined, the results of which demonstrated that the strength of the structure is weak, and that the adhesive and reinforced core between the face plate and the web plate is the primary weakness of the structure. A numerical simulation method was verified using the results of the mechanical tests, and five characteristic paths at the connection area were established. The stresses and displacements along the five paths were calculated using the numerical method. Then, variations in the geometric parameter and the strength and weight of the connection were summarised. The optimal angle of the adhesive bonding area is approximately 60°, which supports the optimal design and practical application of the lightweight ship adhesive-bonded connection structure.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulations and tests of composite marine structures under low-velocity impact
Autorzy:
Zhu, Zhaoyi
Li, Xiaowen
Chen, Qinglin
Cai, Yingqiang
Xiong, Yunfeng
Tematy:
low-velocity impact
marine structure
composites
test
finite element analysis
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:
https://bibliotekanauki.pl/articles/1573692.pdf  Link otwiera się w nowym oknie
Opis:
Due to their excellent performance, composite materials are increasingly used in the marine field. It is of great importance to study the low-velocity impact performance of composite laminates to ensure the operational safety of composite ship structures. Herein, low-velocity drop-weight impact tests were carried out on 12 types of GRP laminates with different layup forms. The impact-induced mechanical response characteristics of the GRP laminates were obtained. Based on the damage model and stiffness degradation criterion of the composite laminates, a low-velocity impact simulation model was proposed by writing a VUMAT subroutine and using the 3D Hashin failure criterion and the cohesive zone model. The fibre failure, matrix failure and interlaminar failure of the composite structures could be determined by this model. The predicted mechanical behaviours of the composite laminates with different layup forms were verified through comparisons with the impact test results, which revealed that the simulation model can well characterise the low-velocity impact process of the composite laminates. According to the damage morphologies of the impact and back sides, the influence of the different layup forms on the low-velocity impact damage of the GRP laminates was summarised. The layup form had great effects on the damage of the composite laminates. Especially, the outer 2‒3 layers play a major role in the damage of the impact and the back side. For the same impact energy, the damage areas are larger for the back side than for the impact side, and there is a corresponding layup form to minimise the damage area. Through analyses of the time response relationships of impact force, impactor displacement, rebound velocity and absorbed energy, a better layup form of GRP laminates was obtained. Among the 12 plates, the maximum impact force, absorbed energy and damage area of the plate P4 are the smallest, and it has better impact resistance than the others, and can be more in line with the requirements of composite ships. It is beneficial to study the low-velocity impact performance of composite ship structures.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zbiór dopuszczalnych planów montażu wielkowymiarowych konstrukcji oceanotechnicznych
Set of feasibile assembly plans of large - size marine structures
Autorzy:
Iwańkowicz, R.
Tematy:
montaż
spawanie
kadłub statku
stocznia
marine structure
assembly
welding
position
ship hull
shipyard
Pokaż więcej
Wydawca:
Polskie Towarzystwo Zarządzania Produkcją
Powiązania:
https://bibliotekanauki.pl/articles/340064.pdf  Link otwiera się w nowym oknie
Opis:
The aim of the article is presenting a mathematical model of the assembly process of large-size marine structures. Numerical encoding approach of essential features of the structure and welding methods is proposed. The model takes into account information about the geometry of the connections between elements and their orientation in space during the assembly process. Welding processes are characterized by positions range of their application. The assembly process is shown as a matrix form. Assembly planning is based on the allocation of welding processes into stages and the selection of welding method and assembly position for each stage. It is shown that a lot of such plans can be generated and many of them are unacceptable. Space of feasible plans is defined by set of constraints. These conditions verify that the assembly plan performs a task of welding of all joints and whether it is feasible for particular methods. The methods for calculating the impact of all conditions . an accurate deterministic and randomized approximate are proposed. It is shown that assumed conditions dramatically reduce the set of assembly plans. Moreover, the method of including additional conditions into the model according to the connections making sequence is presented. Sample calculations are shown in two examples . first that is extremely simplified, allowing for a full deterministic analysis of the problem, and a second that is more complex, requiring a partial approximate approach. The article indicates the possibility of using the optimization of the assembly plan. Furthermore, the set of applicable criteria is proposed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of the calculation methods of the marine propeller’s blade thickness
Autorzy:
Murawski, L.
Tematy:
marine propeller
strength
vibration
solid structure in fluid
FEM modelling methodology
Pokaż więcej
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Powiązania:
https://bibliotekanauki.pl/articles/244269.pdf  Link otwiera się w nowym oknie
Opis:
Strength of the propellers with the skewback greater than 25º has to be numerically analysed according to marine classification societies. The finite element method (FEM) is advised for that kind of calculations. Classical and typical propellers (skewback < 25º) may be designed on the base of empirical equations given by the societies. The minimal thickness of the propeller blade is determined by the equations. Each classification society has their own empirical formula. Sometimes, well-designed propeller for one society has not enough strength according to the other society. What is more, propellers designed according to the empirical formulas might be not optimal. Comparative analysis of the marine propeller’s blade strength has been described in the article. Calculations of the propeller’s blade thickness have been done by two international classification societies’ empirical formulas (ABS and DNV). The results have been compared with Finite Element Method calculations (NASTRAN program). The methodology of propeller static strength vibration analyses is presented. Numerical calculation methodology is based on solidstate mechanics with loadings determined by fluid mechanics calculations. Steady state and transient fluid flow of the propeller’s working conditions were taken into account. In order to determine the optimal modelling method of the propeller several different numerical models were compared, including free model of whole propeller and single blade with boundary conditions placed in the foot. The propeller optimization was the main target of the analyses. Propeller blade thickness might be reduced after FEM method analysis - the propeller mass saving can be achieved.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the optimization methods to the search of marine propulsion shafting global equilibrium in running condition
Autorzy:
Ursolov, Aleksandr
Batrak, Yuriy
Tarelko, Wieslaw
Tematy:
marine propulsion shafting
bearing lubrication
fluid-structure interaction
finite-element method
optimization
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:
https://bibliotekanauki.pl/articles/258800.pdf  Link otwiera się w nowym oknie
Opis:
Full- film hydrodynamic lubrication of marine propulsion shafting journal bearings in running condition is discussed. Considerable computational difficulties in non-linear determining the quasi-static equilibrium of the shafting are highlighted. To overcome this problem the approach using two optimization methods (the particle swarm method and the interior point method) in combination with the specially developed relaxation technique is proposed. The developed algorithm allows to calculate marine propulsion shafting bending with taking into account lubrication in all journal bearings and exact form of journal inside bearings, compared to results of most of the publications which consider lubrication only in the aft most stern tube bearing and assume rest of bearings to be represented by points. The calculation results of typical shafting design with four bearings are provided. The significance of taking into account lubrication in all bearings is shown, specifically more exact values of bearings’ reactions, shafting deflections, minimum film thickness and maximum hydrodynamic pressure in the stern tube bearing in case of considering lubrication in all bearings.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of consolidation settlement and creep deformation of artificial island revetment structure in a large-scale marine reclamation land project
Autorzy:
Zhao, J.
Zhou, T.
Wang, G.
Tematy:
marine reclamation land
Soft-Soil-Creep model
consolidation settlement
pore pressure
micro-structure
numerical analysis
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:
https://bibliotekanauki.pl/articles/258848.pdf  Link otwiera się w nowym oknie
Opis:
In order to analyze the influential factors of soft foundation settlement in a marine reclamation land project, the consolidation settlement and pore pressure dissipation of the entire area are numerically simulated using Soft-SoilCreep Model, in which the PLAXIS finite element software for professional geotechnical engineering is applied and empirical data of Japanese Kansai’s airport project are used. Moreover, the figures of settlement and pore pressure results in the different basic period are drawn, and the corresponding analysis conclusions are obtained based on the comparison among the results from the computational parameters of depth. In addition,, the influence rules of various parameters on settlement results is concluded through running the parameter sensitivity analysis in Soft-Soil-Creep Model, and the experience and conclusions can be for reference in the design and con-struction of similar large-scale marine reclamation land project. Also the empirical value method of the creep index has not been applied widely. Further research needs to be done.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustically measured diurnal vertical migration of fish and zooplankton in the Baltic Sea - seasonal variations
Autorzy:
Szczucka, J.
Tematy:
zooplankton
fish
temperature
acoustic measurement
marine organism
physical structure
diurnal migration
vertical migration
seasonal variation
water
salinity
Baltic Sea
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:
https://bibliotekanauki.pl/articles/48748.pdf  Link otwiera się w nowym oknie
Opis:
Acoustic measurements were conducted at different seasons in the last five years at a fixed point of the Baltic Sea at a frequency 30 kHzcon currently with temperature and salinity sampling. Echosounding records were used to determine the seasonal and diurnal migration patterns of scattering layers in accordance with thermohaline conditions. Different seasonal patterns of nocturnal aggregations of organisms dependent on the temperature gradient in the thermocline were found. This paper illustrates the diurnal distributions of sound scattering layers and analyses the way they are linked to the physical structure of the water.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Qualitative importance measures of systems components - a new approach and its applications
Jakościowe miary ważności elementów systemów - nowe podejście i jego zastosowania
Autorzy:
Chybowski, L.
Gawdzińska, K.
Wiśnicki, B.
Tematy:
fault tree analysis (FTA)
component importance
qualitative analysis
functional structure
reliability structure
marine power plant system
analiza drzewa niezdatności
ważność elementu
analiza jakości
struktura funkcjonalna
struktura niezawodnościowa
system siłowni okrętowej
Pokaż więcej
Wydawca:
STE GROUP
Powiązania:
https://bibliotekanauki.pl/articles/409650.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents an improved methodology of analysing the qualitative importance of components in the functional and reliability structures of the system. We present basic importance measures, i.e. the Birnbaum’s structural measure, the order of the smallest minimal cut-set, the repetition count of an i-th event in the Fault Tree and the streams measure. A subsystem of circulation pumps and fuel heaters in the main engine fuel supply system of a container vessel illustrates the qualitative importance analysis. We constructed a functional model and a Fault Tree which we analysed using qualitative measures. Additionally, we compared the calculated measures and introduced corrected measures as a tool for improving the analysis. We proposed scaled measures and a common measure taking into account the location of the component in the reliability and functional structures. Finally, we proposed an area where the measures could be applied.
Artykuł przedstawia udoskonaloną metodykę jakościowej analizy ważności elementów w niezawodnościowej i funkcjonalnej strukturze systemu. Przedstawiono podstawowe miary ważności, takie jak: strukturalna miara Birnbauma, rząd najmniejszego minimalnego przekroju niezdatności, liczba powtórzeń i tego zdarzenia w drzewie niezdatności oraz miara strumieni. Jakościowa analiza ważności elementów została zilustrowana na przykładzie podsystemu pomp obiegowych i podgrzewaczy instalacji zasilania paliwem silnika napędu głównego statku kontenerowego. Dla przeprowadzenia jakościowej analizy ważności elementów opracowano model funkcjonalny systemu oraz drzewo niezdatności. Ponadto, porównano wartości wyznaczonych miar ważności i wprowadzono skorygowane miary ważności jako narzędzie usprawniające proces analizy. Zaproponowano wykorzystanie skalowanych i powszechnie znanych miar zależnych od lokalizacji elementów w strukturze niezawodnościowej i funkcjonalnej. Zaproponowano także możliwe obszary wykorzystania zaprezentowanych miar.
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies