Wyniki wyszukiwania - BazTech

1

Accelerations Caused by Underwater Explosions on the Naval Gun Foundation

Szturomski Bogdan, Kiciński Radosław, Milewski Stanisław

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

129--141

EN

The manuscript analyzes the impact of a non-contact underwater explosion on the foundation of a 35 mm naval cannon mounted on board a Project 258 minehunter. The finite element method was used to complete the task. Cole's empirical formulas were used to describe the distribution of the pressure wave from the explosion of the TNT charge in water as a function of distance, time, and mass. The hull geometry was reflected based on technical documentation as a shell structure reinforced with beam-bar elements. Devices with large weights were represented as rigid bodies. Simplifications were used to minimize the number of degrees of freedom. The construction of ship's hull is made of non-magnetic austenitic steel. The dynamic characteristics of this steel were determined based on static and dynamic tensile tests. The Johnson-Cook constitutive model was used to describe the material properties of steel. As part of the work, the impact resistance study of marine structures was presented, how it is defined by the existing regulations in the Polish Navy was considered, and the scope of their applicability was given. The scientific innovation of the presented work consists of checking and specifying the guidelines for designing and constructing warships.

2

Explosion effects in the vicinity of the Nord Stream 2 pipeline on the environment : theoretical analysis

Szturomski Bogdan, Kiciński Radosław

Polish Hyperbaric Research

|

2022

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nr 4(81)

53--68

EN

The study analyzes the effects of an underwater explosion recorded in the Baltic Sea on September 26, 2022, with coordinates: 54.675 North and 15.574 East at a depth of 76.2 m. Based on data from the seismic monitoring system, the detonated charges were estimated at 750 kg of TNT. Then, the empirical equations of R. H. Cole and Warren D. Reid were used to calculate water pressure distribution and determine the danger zones for marine technology, ships, people, and sea fauna. The results are presented in graphical and tabular form. Based on the calculations, the explosion impact area was determined at over 6,700 m from the epicenter.

3

An analytical solution for dynamic response of water barrier subjected to strong shock waves caused by an underwater explosion to dams

Lu L., Zou D., Zhu Y., Dong Y., Zuo C., Wu Y.

Polish Maritime Research

|

2017

|

S 2

111--117

EN

Shock waves arriving at a dam site are close to plane waves when the center of an underwater explosion is far from the dam site. In general, the wave pressure is calculated with COLE empirical formula. The COLE formula is a negative exponential function with respect to time. In this paper, a new analytical solution algorithm is proposed, which does not require the use of step-by-step time integration. In Comparison with the step-by-step time integration, the proposed algorithm requires relatively less calculation and avoids high-frequency oscillation. Furthermore, the vertical upstream surface and the sloping upstream surface in two types of the dams are analyzed in this paper. The research results indicate that the analytical solution can be applied for a dam with a vertical upstream surface. However, because the upstream face of a dam is inclined, the analytical solution can be obtained only for dams that are at lower height. Whenever the height of a dam is higher, then no analytical solution can be obtained, and only the use of step-by-step time integration can obtain a solution.

4

Modeling impact resistance of the ships hull

Grządziela A., Jurczak W.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2015

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nr 41 (113)

61--64

EN

Ships’ hull usually works in a hard environment caused by static forces and permanent dynamic loads. Modeling of dynamical reactions could bring information to the designer for recognizing the level of hazard for hull structure and propulsion system. A paper presents a proposal of identification of a degree of hazard the ships hull forced from underwater explosion. A theoretical analysis was made of influence of changes of hull structure in vicinity of shaft bearing foundations. The main problem of naval vessels is a lack of dynamical requirements of stiffness of the hull. Modelled signals and hull structure were recognized within sensitive symptoms of three sub models: model of hull structure, model of impact and model of propulsion system. All sub models allow testing forces and their responses in vibration spectrum using SIMULINK software.

5

The effect of an underwater explosion on a ship

Szturomski B.

Zeszyty Naukowe Akademii Marynarki Wojennej

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2015

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R. 56 nr 2 (201)

57--73

EN

This article contains a synthetic account of an underwater explosion and its effects. It presents diagrams of the gas bubble radius in the function of explosive charge mass and detonation depth as well the values of pressure on the front of a shock wave in the function of range and mass of TNT charge: 1, 10, 50, 250, 1000 kg (following T. L. Geers and K. S. Hunter). It also presents a classification of underwater explosions and their effect on a ship’s hull. It includes the classification of modern sea mines throughout the world and also contains a diagram which can be used to estimate the effects of a shockwave on a ship’s hull in the function of TNT charge mass, following the Cole’s formulas.

PL

W artykule zamieszczono syntetyczny opis wybuchu podwodnego i jego skutki. Przedstawiono wykresy promienia pęcherza gazowego w funkcji masy ładunku i głębokości detonacji oraz wartości ciśnienia na froncie fali uderzeniowej w funkcji odległości i masy ładunku TNT wynoszącej 1, 10, 50, 250, 1000 kg (według T. L. Geersa i K. S. Huntera). Przedstawiono klasyfikację wybuchów podwodnych i ich oddziaływanie na kadłub okrętu. Przedstawiono klasyfikację współczesnych min morskich świata. Opracowano wykres umożliwiający szacowanie skutków oddziaływania fali uderzeniowej na kadłub okrętu w funkcji masy ładunku TNT według wzorów Cole’a.

6

Kadłuby laminatowe dla okrętów zwalczania min : problemy technologiczne

Grządziela A.

Przetwórstwo Tworzyw

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2014

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[R.] 20, nr 1 (157)

21--27

PL

Artykuł przedstawia problem obliczeń konstrukcji kadłubów niszczycieli min wykonanych z laminatów GRP. Scharakteryzowano zadania niszczycieli min oraz przedstawiono problem odporności udarowej na falę detonacji podwodnej. Wskazano metody obliczeń parametrów fali wywołującej odkształcenia sprężyste kadłuba okrętowego oraz oddziaływanie dynamiczne na struktury wewnętrzne. Przedstawiono współcześnie stosowane metody realizacji konstrukcji kadłubów GRP oraz łączenia z elementami stalowymi.

EN

The paper presents the problem of calculating the hull structures of minehunters made from GRP laminates. It characterizes the task of minehunters and presents the problem of impact resistance to the waves of underwater detonations. This method of calculating the parameters of the indicated wave causing elastic deformation of the hull of the ship and dynamic effects on the internal structures. The paper presents the implementation of modern methods of constructing GRP hulls and connecting laminate with steel part.

7

Szacowanie odporności udarowej okrętu z wykorzystaniem symulacji komputerowej

Flis L.

Logistyka

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2014

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nr 6

650--654, CD 2

PL

Omówiono przesłanki, wyboru metody Lagrange’a do modelowania odporności udarowej okr ę tu. Przedstawiono wyniki szacowania odporności udarowej okrętu obciążonego ciśnieniem od niekontaktowego wybuchu podwodnego z wykorzystaniem uproszczonego modelu dyskretnego uproszczonego. Odniesiono uzyskane wyniki do eksperymentu.

EN

Discusses the rationale, choose the method of Lagrangian modeling of the impact resistance of the ship. Presents the results of estimating the impact resistance of the ship loaded with pressure from non- contact underwater explosion using a simplified model of a discrete simplified. They referred to the results of the experiment.

8

Monitoring system of extreme loadings of propulsion system’s foundation : design assumptions

Kyzioł L., Murawski L.

Journal of KONES

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2013

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Vol. 20, No. 1

155--162

EN

Project of on-line diagnostic (monitoring) system of marine propulsion system working parameters is the authors' general target. Proper propulsion system’s foundation is one of the most important parameters for its reliable operation. Different types of quasi-static loadings and dynamic excitations can be observed during ships exploitation. Presented research has been limited to extreme loadings. Underwater explosions or ship groundings are considered examples of extreme foundation loadings. Analysis of the physical parameters of the extreme forces has been presented in the first part of the paper. Water pressure spatial and non-spatial (time) distribution during underwater explosion has been analysed as an example. Short overview of the dynamic mathematical models of underwater explosions is presented. Time function of vibrations acceleration of ship construction is important design assumption of planned Structural Health Monitoring (SHM) system. Propulsion system's foundation loading measurements should take into account general ship hull deformation (in the aft part of the ship) as well as reactions changes of main engine and shaft line bearings. Ship hull deformation should be monitored as quasi-continuous measurements, along whole propulsion system. Optical Time-Domain Reflectometer method (OTDR) is planned for hull deformation monitoring. Propulsion system bearings' reactions are a source of local foundation pads' strain changes. Fibre Bragg Grating (FBG) sensors are the best for that kind of measurements, in authors opinion. Both techniques (OTDR and FBG) have been shortly described in the paper. Scheme of monitoring system of marine propulsion systems foundation's loadings are proposed in the end of the article.

9

Diagnosis design of ship hull strength of treated by dynamic load

Grządziela A., Szturomski B., Kluczyk M.

Diagnostyka

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2013

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Vol. 14, No. 2

23--30

EN

Ship shock tests have been conducted for shock qualification of hull integrity and proper operation systems and subsystems. The ship shock trial identifies design and construction and it also validates shock hardening criteria. The main problem is that ship shock trials are costly. Numerical modeling and simulation, using FEM, may provide information to look into the details of fluid model, dynamic characteristics of ship hull and its internal component. The ship shock modeling and simulation has been performed and the predicted results were compared with ship shock test data made into sea trials. The preliminary studies of shock analysis approach are presented and the important parameters are discussed.

PL

Testy udarnościowe kadłubów prowadzone są w celu oceny ich integralności oraz poprawności działania wszystkich zamontowanych systemów. Testy udarnościowe pozwalają na identyfikację i ocenę konstrukcji oraz weryfikują odporność kadłuba. Głównym problemem jest ich wysoka cena z racji konieczności realizacji na prototypach. Modelowanie i symulacja za użyciem MES, może dostarczyć informacji do oceny bryły wody towarzyszącej, dynamicznych właściwości kadłuba i elementów wyposażenia. W artykule przedstawiono modelowanie i symulację uderzenia w fali uderzeniowej w kadłub a uzyskane wyniki porównano z wynikami poligonowymi.

10

Model of impact underwater detonation

Grządziela A.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2012

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z. 3/89

29--34

EN

Ships’ hull usually works in a hard environment caused by static forces and permanent dynamic loads. Modelling of dynamical reactions could bring information to the designer for recognizing the level of hazard for hull structure and propulsion system. A paper presents a proposal of identification of a degree of hazard the ship’s hull forced from underwater explosion. A theoretical analysis was made of influence of changes of hull structure in vicinity of shaft bearing foundations. Modelled signals and hull structure were recognized within sensitive symptoms of three sub models: model of hull structure, model of impact and model of propulsion system.

PL

W artykule zaprezentowano wyniki analizy i modelowania kadłuba odpornego na detonacje podwodne. Przeprowadzone badania ukierunkowano na określenie wpływu detonacji na strukturę okrętowej linii wałów. Podstawowym problemem sygnalizowanym w artykule jest zachowanie sztywności kadłuba poddanego detonacji. Badania obejmują modelowanie struktury kadłuba, modelowanie oddziaływania detonacji podwodnej oraz modelowanie elementów układu napędowego. Wszystkie modele są ze sobą powiązane a uzyskane wyniki są efektem zastosowanie narzędzi modelowych SIMULINK.

11

Model of impact underwater detonation

Grządziela A.

Journal of KONES

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2012

|

Vol. 19, No. 2

191-199

EN

Minehunters are subjected to specific sea loads due to waving and dynamical impacts associated with underwater explosion. Sea waving can be sufficiently exactly modelled by means of statistical methods. Much more problems arise from modelling impacts due to underwater explosion. Knowledge of a character of impulse loading which affects ship shaft line can make it possible to identify potential failures by means of on-line vibration measuring systems. The problem of influence of sea mine explosion on hull structure is complex and belongs to more difficult issues of ship dynamics. Underwater explosion is meant as a violent upset of balance of a given system due to detonation of explosives in water environment. A paper presents a proposal of identification of a degree of hazard the ship's hull forced from underwater explosion. A theoretical analysis was made of influence of changes of hull structure in vicinity of hull. The main problem of naval vessels is a lack of dynamical requirements of stiffness of the hull. Modelled signals and hull structure were recognized within sensitive symptoms of three sub models: model of hull structure, model of impact and model of propulsion system. All sub models allow testing forces and their responses in vibration spectrum using SIMULINK software and FEM models.

12

Ship impact modeling of underwater explosion

Grządziela A.

Journal of KONES

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2011

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Vol. 18, No. 2

145-152

EN

Ship shock tests have been conducted for shock qualification of hull integrity and proper operation systems and subsystems. The ship shock trial identifies design and construction and it also validates shock hardening criteria. The main problem is that ship shock trials are costly. Numerical modelling and simulation, using FEM, may provide information to look into the details of fluid model, dynamic characteristics of ship hull and its internal component. The ship shock modelling and simulation has been performed and the predicted results were compared with ship shock test data made into sea trials. The preliminary studies of shock analysis approach are presented and the important parameters are discussed. The course of pressure changes in the shock wave and the acceleration of the ship hull during an underwater explosion in a fixed point, coating elements with chosen junction forces (example), designation of degrees of freedom of rectangular plate, simplified diagram of interactions in the process of detention in the hull of a ship, analysis of the acceleration of the Newmark method, calculations based on central difference method, schematic anchor launch, layout of the apparatus and the conditions for an explosion, the course of the accelerations recorded in the ship's hull, The course of simulation of the acceleration are presented in the paper.

13

A study on the UNDEX cup forming

El Mokadem A. E., Wifi A. S., Salama I.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

556-562

EN

Purpose: This work investigates the use of the underwater explosion (UNDEX) for the free and plug assisted cup forming processes. Design/methodology/approach: A 3D finite element model is built to simulate the process of the UNDEX cup forming using ABAQUS finite element code. Johnson-Cook (JC) material plasticity model is used to represent strain rate sensitivity of the used materials. Johnson- Cook damage criterion is employed to detect the onset of damage in the cup forming process. Findings: Both relatively hard and soft plugs are considered and the effects of using different plug materials on cup profile, strains and the limiting drawing ratios are given. The onset of damage in this process is also indicated. The results suggest that a relatively hard plug can enhance the control of the cup shape and the uniformity of strain distribution leading to increased limiting drawing ratio. Research limitations/implications: This work suggests a methodology for the prediction of shape, different strain distribution, the limiting drawing ratio and the energy required for UNDEX cup forming process. Practical implications: This study could be useful in non-conventional high energy rate forming industry. Originality/value: The study reveals the possibility of producing flat-bottomed cup by the relatively hard plug assisted UNDEX forming technique.

14

Ruch okrętu jako belki sprężystej spowodowany podwodnym wybuchem

Dobrociński S., Pawlędzio A.

Przegląd Mechaniczny

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2008

|

nr 5

38-42

PL

Okręty wojenne są one narażone na różnego rodzaju oddziaływania środków bojowych nieprzyjaciela, w tym między innymi miny morskie. Powinny mieć odporność udarową na takim poziomie, który będzie gwarantował bezpieczeństwo okrętu i załogi w określonym zakresie podwodnych wybuchów. Obecnie dzięki rozwijaniu technik obliczeniowych stopień odporności udarowej okrętu można oszacować na podstawie symulacji komputerowych, wykorzystujących skomplikowane algorytmy obliczeniowe. Przedstawiona w artykule metoda obliczeniowa jest jednym z możliwych sposobów, który może służyć do oceny odporności udarowej okrętu. Obliczenia zaproponowaną metodą wykonano dla jednego z okrętów polskiej marynarki wojennej, traktując jego konstrukcję jako belkę sprężystą o zmiennym przekroju i rozkładzie masy.

EN

Warships are run a risk of various combat agents influence, among other things, marine mines. These warships should exhibit impulse strength which guarantees safety of the ship and crew at specified range of underwater explosions. Nowadays, thanks to numerical methods development, level of impulse strength of the warship can be evaluated on the base on computer simulations, which applies complex computational algorithms. Analytical method, presented in the paper, is one of possible method to assessment of warship's impact strength. Applying proposed analytical method there was performed calculations for one of warship belonging to Polish Navy, treating its construction as a elastic beam with variable section and mass distribution.

15

Effects Of Underwater Explosion On Minehunters Shafts Lines

Grządziela A.

Journal of Polish CIMAC

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2008

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Vol. 3, no 2

9-13

EN

Ships’ propulsion plant usually works in a hard environment caused by static forces and permanent dynamic loads. Exciding of tolerated values of shaft alignments causes a damage of radial and thrust bearings in relative short time. Modeling of dynamical reactions could bring information to the designer for recognizing the level of hazard for propulsion system. A paper presents a proposal of identification of a degree of hazard to ship shaft line due to forces of underwater explosion. A theoretical analysis was made of influence of changes in co-axiality of shafts resulting from elastic deformations of hull structure in vicinity of shaft bearing foundations. The main problem of naval vessels is a lack of dynamical requirements of stiffness of the hull. Modelled signals were recognized within sensitive symptoms of two sub models: model of propulsion system and model of shafts misalignment. Both sub models allow testing forces and their responses in vibration spectrum using SIMULINK software.

16

Dynamics of minehunters shafts lines

Grządziela A.

Diagnostyka

|

2008

|

nr 1(45)

25-30

EN

Ships' propulsion plant usually works in a hard environment caused by static forces and permanent dynamic loads. Exciding of tolerated values of shaft alignments causes a damage of radial and thrust bearings in relative short time. Modeling of dynamical reactions could bring information to the designer for recognizing the level of hazard for propulsion system. A paper presents a proposal of identification of a degree of hazard to ship shaft line due to forces of shafts misalignment. A theoretical analysis was made of influence of changes in co-axiality of shafts resulting from elastic deformations of hull structure in vicinity of shaft bearing foundations. The main problem of naval vessels is a lack of dynamical requirements of stiffness of the hull. Modelled signals were recognized within sensitive symptoms of two sub models: model of propulsion system and model of shafts misalignment. Both sub models allow testing forces and their responses in vibration spectrum using SIMULINK software.

PL

Jednym z podstawowych problemów w konstrukcji okrętów jest brak precyzyjnych wymagań w zakresie sztywności kadłuba. Oddziaływania dynamiczne mogą powodować elastyczne odkształcenia, które oddziaływają na łożyska linii wałów. Referat prezentuje propozycję identyfikacji zagrożeń dla linii wałów okrętowych wynikających z przekroczenia parametrów współosiowości. Przedstawiono analizy teoretyczne dynamiki wału śrubowego z uwzględnieniem zagadnienia przesunięcia osi wału wynikającego z obciążeń dynamicznych kadłuba. Modelowanie reakcji dynamicznych może umożliwić budowę bazy danych dla potrzeb systemu monitoringu. Przedstawione modele wykonane w środowisku SIMULINK pozwalają testować reakcje dynamiczne spotykane w rzeczywistych warunkach eksploatacji okrętu.

17

Analiza oddziaływań dynamicznych na łożyska linii wałów okrętów do zwalczania min.

Grządziela A.

Zagadnienia Eksploatacji Maszyn

|

2007

|

Vol. 42, nr 2

81-90

PL

Linie wałów są zazwyczaj obliczane i konstruowane indywidualnie dla wszystkich typów maszyn. Obliczenia są dokonywane z uwzględnieniem zadań stawianych maszynom, obciążeniom dynamicznym występującym w na łożyskach etc. Typowym przykładem konstrukcji jest linia wałów okrętów do zwalczania min. Współczesne okrętowe układy napędowe są obliczane przy obciążeniach statycznych, a w procesie prób zdawczych sprawdzane przy zmiennych obciążeniach. Podstawowym zadaniem obliczeniowym jest wyeliminowanie ewentualnych rezonansów drgań wzdłużnych, giętnych i skrętnych. Analiza obciążeń występujących w linii wałów okrętowych wskazuje na występowanie silnych oddziaływań dynamicznych wpływających na niezawodność układu napędowego. Oddziaływanie dynamiczne wybuchu podwodnego może spowodować powstanie nieoczekiwanych w obliczeniach wymuszeń. Wartości parametrów współosiowości mogą zostać przekroczone chwilowo, a nawet trwale. Powstające drgania powodują zmiany w zakresie dynamiki oraz powstawanie prędkości krytycznych drugiego rodzaju, które w efekcie są w stanie szybko zniszczyć układy łożyskowe. Modelowanie oddziaływań dynamicznych może dostarczyć informacji niezbędnych w procesie projektowania dla rozpoznania występujących zagrożeń w układzie napędowym niszczyciela min.

EN

Series shaft lines are calculated and constructed individually for all types of machines. Process of calculation covers specific profile of operation like a main task, no stationary, dynamical forces etc. The typical example of this kind of problem is minehunter propulsion system. Modern marine propulsion systems are calculated in static and finally checked for fatigue loads. Elimination of resonance forces need to be calculated shafts for identify axial, radial and torsion vibrations. Analyze of calculation of periodical and random sea loads, bring a strong effect on dynamic behavior of shaft lines bearings and finally on their reliability and survivability. Dynamical reaction caused by underwater explosions brings unexpected forces. The tolerated values of shafting alignment can be variable or permanently changed. Every transverse vibration in the shaft coupling makes disturbance of shafts rotation movement, it results in changes of second critical mode of velocity which provide to resonance and probability of bearing system damage. Modeling of dynamical reactions could brings information to the project data base for recognizing level of hazard for propulsion system of the naval vessels.

18

An analysis of possible assessment of hazards to ship shaft line, resulting from impulse load

Grządziela A.

Polish Maritime Research

|

2007

|

nr 3

12-20

EN

This paper presents a proposal of identification of a degree of hazard to ship shaft line due to impulse load caused by underwater explosion. A theoretical analysis was made of influence of changes in co-axiality of shafts on second-kind critical velocities resulting from elastic deformations of hull structure in vicinity of shaft bearing foundations. Results are presented of pilotage tests of underwater explosion performed on training water area. A preliminary mathematical model of underwater explosion is given with taking into account mass of explosives and distance from the tested object. The drawn conclusions show a way of identification of hazard to shaft line by using spectral analysis and time - runs of vibration signals recorded at shaft bearings.

19

The consequences of underwater explosion on the general cargo vessel MS "JÓZEF WYBICKI"

Dobrociński S. S., Powierza Z.

Journal of KONES

|

2007

|

Vol. 14, No. 1

181-188

EN

The article describes the case of m/s "Józef Wybicki" coming across a mine. The result of explosion was numerous damages of deck devices as well as in the power station. Despite the lack of damages in the hull the unit was not capable of continuing the cruise. The photographs presented in the article show important damages caused by impact load. The elements such as the trunk of the electric engine, bearings of the lines of hoisting appliance's shafts etc. made of fragile materials are the most vulnerable to damages. Another cause of the damages was construction solutions of mounting the ship's equipment that were susceptible to impact load, e.g. retaining mounting of electric engines. Elements of ship construction makes its own kind wave guide through which the propagation of the energy inwards of the battleship follows. The character of the flow of the energy in construction ship is difficulty to qualify. The diffraction, refraction and interference of waves appear in elements of the ship. Except damages of elements performed from fragile materials the damage in nodes of connections of steel-elements appears.

PL

W artykule przedstawiono przypadek wejścia na minę statku m/s "Józef Wybicki". Na skutek wybuchu nie kontaktowego wystąpiły rozliczne uszkodzenia zarówno w siłowni, jak i urządzeń pokładowych. Pomimo braku uszkodzeń kadłuba jednostka nie była zdolna do kontynuowania rejsu. Przedstawione w pracy wybrane zdjęcia obrazują istotne uszkodzenia powstałe w wyniku obciążenia udarowego. Najbardziej narażone na uszkodzenia były elementy wykonane z materiałów kruchych, takich jak korpusy silników elektrycznych, łożysk linii wałów wciągarek ładunkowych itp. Inną przyczyną występowania uszkodzeń były wrażliwe na obciążenia udarowe rozwiązania konstrukcyjne zamocowania wyposażenia okrętowego, zamocowania wspornikowe silników elektrycznych. Każdy z elementów konstrukcji okrętu stanowi swego rodzaju falowód, przez który następuje propagacja energii do wnętrza okrętu. Trudno jest określić charakter rozpływu energii w konstrukcji okrętu. W poszczególnych elementach występuje dyfrakcja, refrakcja oraz interferencja fal. Oprócz uszkodzeń elementów wykonanych z materiałów kruchych wystąpiły uszkodzenia w węzłach połączeń elementów stalowych.

20

Ship movement as a stiff body induced by a mine explosion

Dobrociński S., Pawlędzio A.

Journal of KONES

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2007

|

Vol. 14, No. 1

189-198