НИЦ "Моринтех"

The stiffness matrixes of  bended and compressed-torsioned bar

Manukhin V. A., Lukjanova L. E.
State Marine Technical University of St. Petersburg

e-mail: nikal6@mail.ru
tel.: (812) 494-09-42
The problem of a bend of the compressed-torsioned bar taking into account mutual influence of compression and torsion on a bending is considered. Stiffness matrixes of a bar finite element are received, allowing to consider both axial and a tangential torque moment.
Key words: finite element, stiffness matrix, torque moment.

ESTIMATION OF CRITERIA OF FAILURE OF SHIP STRUCTURES AT NUMERICAL MODELLING OF COLLISION OF SHIPS

Vasiliev R. V., Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42
In the present work features of numerical modelling of failure of ship structures are considered at collision of ships. The various criteria of destruction used in models of a finite element method  are investigated. The example of destruction of a deck and side ship is considered at blow of a struck bow. The analysis of influence of various parameters of settlement models on the absorbed energy and total reaction is carried out.
Key words: struck bow, deck stiffened panel, side stiffened panel, finite element method, criteria of destruction, absorbed energy.

RESEARCH OF FORMS OF DEEP PLASTIC DEFORMATION FOR SHIP PANELS UNDER COMPRESSION LOAD

Korshunov V. A., Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42
Article is devoted research of collapse patterns of a stiffened panel  subject to compressing loading, at deep plastic deformation by means of finite element method. Depending on parameters of stiffeners three forms of a limit states are found out. The way of calculation of the ultimate strength of the stiffened panel is offered. Comparison of the ultimate strength with analytical estimations is spent.

Key words: stiffened panel; ultimate strength; finite element method yield stress; compress; overall collapse; plate-induced failure; stiffener-induced failure; local buckling of stiffener web.

RESEARCH OF FORMS OF DEEP PLASTIC DEFORMATION FOR SHIP PANELS UNDER LATERAL PRESSURE

Korshunov V. A., Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42
This paper deals with plastic deformation of stiffened panels under lateral pressure. The cross-section of stiffeners is flat bar. At constant thickness of a plate the sizes of cross-section of stiffeners varied. Forms of ultimate limit state of the panel depending on ratio of rigidity of a plate and stiffeners are revealed. For design and strength assessment of various types of structures such as ships, offshore platforms it has been realized that ultimate limit states (or ultimate strength) are much better basis than the allowable working stresses.
Key words: stiffened panel; ultimate limit states; plastic strain; lateral pressure, finite element method, stiffener.

RESEARCH OF CYCLIC PLASTIC DEFORMATION OF STRUCTURES ON MODELS OF THE METHOD OF FINITE ELEMENTS

Korshunov V. A., Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42
This paper deals with hardening models applied in FEM. The model of nonlinear kinematic hardening is in detail described. The results of numerical analysis and comparison of models of plastic behaviour of a material under cyclic load are presented.
Key words: yield surface, isotropic hardening, kinematic hardening, residual deformations, finite element method.

FEM MODELS FOR ULTIMATE STRENGTH ANALYSIS OF STEEL STIFFENED-PLATE UNDER COMBINED AXIAL COMPRESSION AND LATERAL PRESSURE ACTIONS

Korshunov V. A., Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42

In presented paper application of nonlinear finite element method models for ultimate strength analysis of steel stiffened panels structures under combined axial compression and lateral pressure actions is investigated. Recommendations for development of desing model of finite element method are formulated. The way of the task of initial imperfections in desing model is offered.
Key words: stiffened panel, ultimate limit state, yield stress, compression, lateral pressure, local buckling, finite element method

Method of variation of elastic parameters in calculations of load-carrying ability beam-idealized ship structures

Mironov M. J., Ponomarjov D. A., Rodionov A. A.
Saint-Petersburg State Marine University

e-mail: kafedra_smk@mail.ru
tel.: +7 (812) 494 09 42
Examples of definition of limit loads with method of variation of discrete elastic parameters of beams, frames and grillages realized. The ability and efficiency of this method estimated. Using of this method in optimal design of ship structures analyzed.
Key words: limit equilibrium, rigid-plastic models, finite element method, fictitious stifnesses, limit loads of beam systems, limit surfaces, design of board reinforces.

Calculations of limit loads of the lamellar models of ship structures

Mironov M. J., Rodionov A. A.
Saint-Petersburg State Marine University

e-mail: kafedra_smk@mail.ru
tel.: 8 (812) 494 09 42
Determining of the limit loads of laminas (plates) of ship boarding and of the lamellar models of braced relations under action of distributed forces and concentrated forces is estimated by means of method of variation of elastic parameters in combination with finite-element method. Different equations of limit surfaces in stresses and approach to evaluating of contribution of membrane efforts into load-carrying ability of laminas are investigated.
Key words: finite element method, fictitious stifnesses, limit loads of plates, limit surfaces, bending and membrane stresses, limit deflections.

ANALYSIS OF FAILURE TYPES OF STRUCTURES FROM POLYMER COMPOSITE MATERIALS

Rodionov A. A.. Sycheva S. N.
State Marine Technical University of St. Petersburg

e-mail: sychevasn@rambler.ru
tel.: 8 (812) 494-09-42
In work results of research strength characteristics of deck overlapping from polymeric composite materials by means of settlement models of a method of final elements are presented. Destruction possibility was estimated by means of various criteria. Researches of values of function of destruction in all layers of a composit material has allowed to predict the form of destruction of a design. Results of calculations are compared to results of natural tests and show the good agreement.
Key words: polymer composite material, deck floor, finite element method, failure criterion.

ULTIMATE LIMIT STATE ASSESSMENT OF SHIP PLATED STRUCTURES UNDER COMBINED LOADING CAUSED BY LOCAL PRESSURE AND HULL GIRDER BENDING

Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42
Tumashik G. A., Krylov Shipbuilding Research Institute
In article ultimate state of ship hull plates of the case participating in perception of lateral pressure and the general bend are investigated. For research the finite element method is used. Various kinds of boundary conditions are considered. The estimation of influence of initial plastic deformations from lateral pressure on a ultimate state of plates is executed.
Key words: plates of the ship hull, finite element method, the plastic deformation, combined loading, ultimate state.

ASSESSMENT OF PLASTIC DEFORMATION FORMS AND ULTIMATE LIMIT STATE OF SHIP FLOOR STRUCTURES UNDER UNICOMPONENT LOAD

Rodionov A. A.
State Marine Technical University of St. Petersburg

e-mail:rodionovsmk@yandex.ru
tel.: (812) 494-09-42
Tumashik G. A., Krylov Shipbuilding Research Institute
In work on an example of ship deck overlapping processes of deep plastic deformation under the influence of lateral loading are investigated. As a research the finite element method is accepted. The shell elements and special beam elements are used. At an estimation of maximum loads of bending-shear mechanisms of plastic deformation various models have shown the good agreement.
Key words: ship deck overlapping, finite element method, plastic deformation, beam element, shell element.

Simulation of the sloshing in prismatic tank of the LNG carrier under impact interaction with ice barrier

Dukarskiy A. O., Tkachenko I. V., Tryaskin V. N.,
Tryaskin N. V., Yakimov V. V.
State Marine Technical University of St. Petersburg
e-mail: kgm@smtu.ru
tel.: (812) 494-09-30

Kisilev D. B., Severnoe Design Bureau
e-mail: kdimail@inbox.ru
tel.: (812) 784-82-07
In the present work the simulation of the sloshing in prismatic tank of LNG carrier under impact interaction with ice barrier is described. The parameters of the impulse obtained from the model, which describes the inclination of the ship in the heavy ice condition. Believe, that the ice does not broke under the impact. The Reynolds averaged Navier-Stokes equations coupled by the standard k-ε model are applied for the simulation of the liquid gas dynamics. The volume of fluid method (VoF) is used for the capturing of the interface gas-liquid. The method for the estimation of the safety speed motion in the ice condition, when the pressure load is minimal, is suggested.
Key words: ice, impact interaction, sloshing, pressure loads.

THE METHODOLOGY OF APPLICATION FEM FOR AN ESTIMATION
OF LIFE OF ELEMENTS OF A DRILLING EQUIPMENT

Stroganova O. S., Frumen A. I.
State Marine Technical University of St. Petersburg

e-mail: grossfrum@post.ru
tel.: (812) 494-09-42
On a basis of series of model’s finite - element the methodology of an estimation of condition’s stress-strain and collets resource: of a core extractor of thimbles in a broad band of external conditions is offered. The application of series design models interaction by separate collets and quadrant of a core is substantiated at presence of not contact bands and account of a cyclo symmetry. The parameters of stress-strain conditions of this model are studied at different properties of a ground. On the basis of the found parameters of stress-strain conditions the engineering estimation of life collets (on fatigue curves) is given.
Key words a numerical analysis, finite element method, a drilling equipment, resource, rheology of a ground.