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This paper concentrates on selected aspects of numerical modeling of a short span thin-walled beams. The performed numerical simulations cover different types of finite elements (shell or solid finite elements) and different mesh sizes. Moreover the shape and magnitude of an initial geometrical imperfection is also investigated. The numerical analysis were made with the Newton-Raphson procedure with geometrical and material nonlinearity. The numerical results were compared with the laboratory four point bending test of a thin-walled beam. Furthermore, some guidelines for numerical simulations of a short span thin-walled beams in bending were proposed by authors.This paper concentrates on selected aspects of numerical modeling of a short span thin-walled beams. The performed numerical simulations cover different types of finite elements (shell or solid finite elements) and different mesh sizes. Moreover the shape and magnitude of an initial geometrical imperfection is also investigated. The numerical analysis were made with the Newton-Raphson procedure with geometrical and material nonlinearity. The numerical results were compared with the laboratory four point bending test of a thin-walled beam. Furthermore, some guidelines for numerical simulations of a short span thin-walled beams in bending were proposed by authors.

The paper presents the results of computer modelling using FEA and experimental researches of the influence of technological parameters of burnishing rolling process on resistance to fatigue wear of shafts. For solution of elaborate equation of motion the explicit method was used. This allows to carries out the time analysis of the displacements, strains and stresses state’s in workpieces. In addition, the numerical analyses for the fatigue wear component after burnishing for low frequency loads were carried out. The results of the numerical analysis were experimentally verified by researching the surface layer after burnishing. In addition the shafts on fatigue wear were tested.The paper presents the results of computer modelling using FEA and experimental researches of the influence of technological parameters of burnishing rolling process on resistance to fatigue wear of shafts. For solution of elaborate equation of motion the explicit method was used. This allows to carries out the time analysis of the displacements, strains and stresses state’s in workpieces. In addition, the numerical analyses for the fatigue wear component after burnishing for low frequency loads were carried out. The results of the numerical analysis were experimentally verified by researching the surface layer after burnishing. In addition the shafts on fatigue wear were tested.

The Numerical analysis of heat treatments of TiCN coated AA7075 aluminium alloys is presented in this paper. The Convection-Diffusion-Reaction (CDR) equation with solutions in the Streamlined-Upward Petrov-Galerkin (SUPG) method for different parameters is provided for the understanding of the process. An experimental process to improve the surface properties of AA-7075 aluminium alloy was attempted through the coatings of TiCN and subsequent heat treatments. From the experimental process, optimized temperature and time was obtained which gave the maximum surface hardness and corrosion resistance. The paper gives an understanding and use of the CDR equation for application of the process. Expression to determine convection, diffusion and reaction parameters are provided which is used to obtain the overall expression of the heat treatment process. With the substitution of the optimized temperature and time, the governing equation may be obtained. Additionally, the total energy consumed during the heat treatment process is also developed to give a mathematical formulation of the energy consumed.

This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a nuclear fuel element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts the two dimensional model. It is also observed that for fixed values of Ar, Qt and Bi, there exists a critical value of Th beyond which maximum temperature in the fuel element exceeds its allowable limit.This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a nuclear fuel element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts t...

In this paper, the authors pointed out a study on the profitable combination of forming techniques. More in detail, the attention has been put on the combination of the single point incremental forming (SPIF) and, generally, speaking, of an additional process that can lead to a material thickening on the initial blank considering the local thinning which the sheets undergo at. Focalizing the attention of the research on the excessive thinning of parts made by SPIF, a hybrid approach can be thought as a viable solution to reduce the not homogeneous thickness distribution of the sheet. In fact, the basic idea is to work on a blank previously modified by a deformation step performed, for instance, by forming, additive or subtractive processes. To evaluate the effectiveness of this hybrid solution, a FE numerical model has been defined to analyze the thickness variation on tailored sheets incrementally formed optimizing the material distribution according to the shape to be manufactured. Simulations based on the explicit formulation have been set up for the model implementation. The mechanical properties of the sheet material have been taken in literature and a frustum of cone as benchmark profile has been considered for the performed analysis. The outcomes of numerical model have been evaluated in terms of both maximum thinning and final thickness distribution. The feasibility of the proposed approach will be deeply detailed in the paper.

The paper considers the influence of the assumed error indicator on the final adapted mesh. Provided that threshold values of an error are increased by applying the adaptive procedure, it turns out that final mesh depends on the assumed error indicator. In the paper, there were used the standard error estimates and the error indicator proposed by the author. The proposed error indicator is based on applying hierarchically generalized finite difference method (FDM). In the case of the proposed error indicator, the final adapted mesh is the most optimal for the exact solution.

This paper is devoted to a numerical approach of the biomechanics behavior modeling of a dental implant supported prothesis made up of three elements, and the surrounding bone under the masticatory forces loading. A clinical situation involving both biological (the bone tissue) and non-biological (the three elements of implant prosthesis) materials is simulated. This problem involves fine technical structure details – the threads, tapers, etc with a great impact in masticatory force transmission. Modeling the contact between the implant and the bone tissue is important to a proper bone-implant interface model and implant design. A three-dimensional numerical model is proposed in order to calculate the state of stress and displacement of this complex structure in order to evaluate its stability by determining the risk zones of stress concentration. The results of numerical modeling are in good agreement with other numerical results and clinical casesA comparison between this numerical analysis and clinical cases is performed and a good agreement is obtained.This paper is devoted to a numerical approach of the biomechanics behavior modeling of a dental implant supported prothesis made up of three elements, and the surrounding bone under the masticatory forces loading. A clinical situation involving both biological (the bone tissue) and non-biological (the three elements of implant prosthesis) materials is simulated. This problem involves fine technical structure details – the threads, tapers, etc with a great impact in masticatory force transmission. Modeling the contact between the implant and the bone tissue is important to a proper bone-implant interface model and implant design. A three-dimensional numerical model is proposed in order to calculate the state of stress and displacement of this complex structure in order to evaluate its stability by determining the risk zones of stress concentration. The results of numerical modeling are in good agreement with other numerical results and clinical casesA comparison between this numerical analysis and clinical...

This paper presents the calculation of the gas flow through the piston ring pack of the combustion engine. The paper compares the solution of ordinary differential equations using the standard numerical methods (ode solvers present in MATLAB) with a new method based on the Taylor series – Modern Taylor Series Method.This paper presents the calculation of the gas flow through the piston ring pack of the combustion engine. The paper compares the solution of ordinary differential equations using the standard numerical methods (ode solvers present in MATLAB) with a new method based on the Taylor series – Modern Taylor Series Method.

In the paper a kind of meshless discretization technique, called the Kansa method, is investigated in the context of problems with multiple boundary conditions. This numerical method uses interpolant composed of radial basis functions as well as collocation technique to discretize differential equations. To overcome the problem that appears for equations with multiple boundary conditions, where more equations should be associated with a boundary node than degrees of freedom that exist at this node, an extension of the method is proposed. The key idea lies in the modification of the interpolant with the use of Hermite formulation. The details of the approach are shown in the paper. Moreover, the special attention is paid to estimate respective value of the shape parameter included in radial functions to ensure stability of the solution process and high accuracy. To illustrate usefulness, accuracy and convergence of the method, it is employed to solve a test problem of the bending Kirchhoff plate.

The shearing process such as the blanking of sheet metals has been used often to prepare workpieces for subsequent forming operations. The use of FEM simulation is increasing for investigation and optimizing the blanking process. In the current literature a blanking FEM simulations for the limited capability and large computational cost of the three dimensional (3D) analysis has been largely limited to two dimensional (2D) plane axis-symmetry problems. However, a significant progress in modelling which takes into account the influence of real material (e.g. microstructure of the material), physical and technological conditions can be obtained by using 3D numerical analysis methods in this area. The objective of this paper is to present 3D finite element analysis of the ductile fracture, strain distribution and stress in blanking process with the assumption geometrical and physical nonlinearities. The physical, mathematical and computer model of the process are elaborated. Dynamic effects, mechanical coupling, constitutive damage law and contact friction are taken into account. The application in ANSYS/LS-DYNA program is elaborated. The effect of the main process parameter a blanking clearance on the deformation of 1018 steel and quality of the blank’s sheared edge is analyzed. The results of computer simulations can be used to forecasting quality of the final parts optimization.The shearing process such as the blanking of sheet metals has been used often to prepare workpieces for subsequent forming operations. The use of FEM simulation is increasing for investigation and optimizing the blanking process. In the current literature a blanking FEM simulations for the limited capability and large computational cost of the three dimensional (3D) analysis has been largely limited to two dimensional (2D) plane axis-symmetry problems. However, a significant progress in modelling which takes into account the influence of real material (e.g. microstructure of the material), physical and technological conditions can be obtained by using 3D numerical analysis methods in this area. The objective of this paper is to present 3D finite element analysis of the ductile fracture, strain distribution and stress in blanking process with the assumption geometrical and physical nonlinearities. The physical, mathematical and computer model of the process are elaborated. Dynamic effects, mechanical coupl...

The paper presents numerical tests results of the steel beam with sinusoidally corrugated web, which were performed in the Autodesk Algor Simulation Professional 2010. The analysis was preceded by laboratory tests including the beam’s work under the influence of the four point bending as well as the study of material characteristics. Significant web’s thickness and use of tools available in the software allowed to analyze the behavior of the plate girder as beam, and also to observe the occurrence of stresses in the characteristic element - the corrugated web. The stress distribution observed on the both web’s surfaces was analyzed.The paper presents numerical tests results of the steel beam with sinusoidally corrugated web, which were performed in the Autodesk Algor Simulation Professional 2010. The analysis was preceded by laboratory tests including the beam’s work under the influence of the four point bending as well as the study of material characteristics. Significant web’s thickness and use of tools available in the software allowed to analyze the behavior of the plate girder as beam, and also to observe the occurrence of stresses in the characteristic element - the corrugated web. The stress distribution observed on the both web’s surfaces was analyzed.

This paper presents the new numerical method based on the Taylor series. This method is used to solve a control problem with a simple system. The paper also presents the control problem and the numerical methods used to solve it. It also compares the results obtained by state of the art solvers and the proposed numerical method.This paper presents the new numerical method based on the Taylor series. This method is used to solve a control problem with a simple system. The paper also presents the control problem and the numerical methods used to solve it. It also compares the results obtained by state of the art solvers and the proposed numerical method.

This paper presents the characteristics of the process of longitudinal rolling of shafts and the geometry of the working section of forming rollers with a secant profile. In addition, the analytical formulae defining the geometry of a roller profile were determined. The experiments were carried out on shafts made of S235JR and C45 structural steels and the MSC.Marc + Mentat program was used for the numerical analysis of the rolling process based on the finite element method. The paper analyses the effect of roller geometry on the changes in value of the widening coefficient and the diameter reduction coefficient for the first forming passage. It was found that the mechanical properties of the shaft material have a slight influence on the widening coefficient. The value of the widening coefficient of the shaft increases with increase in the initial diameter of the shaft. Increasing shaft diameter causes an increase of strain gradient on the cross-section of the shaft.

With the progress of China’s nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key components is presented, aiming at revealing the characteristics and rules of finite element modeling of nuclear power valves, and putting forward aprecision control strategy for finite element models for nuclear power valve characteristics analysis.With the progress of China’s nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key compone...

The paper presents the development of recently proposed kinetic model of dynamic mechanical behavior of brittle solids. The model uses the ideas of kinetic theory of strength to describe the inelastic deformation and fracture. The main feature of the modified dynamic model is the introduction of two relaxation times, which determine the patterns of inelastic deformation under dynamic loading, including the dependences of the values of the cohesion and strain hardening coefficient on the strain rate. These relaxation times have the meaning of a generation time of damage of the smallest ranks and a characteristic time of formation of a system of local damage and cracks of the greatest rank. The advantage of a developed dynamic model is the possibility of its implementation within different conventional models of inelasticity of brittle solids. In the paper we implemented the kinetic model within the classical “quasi-static” Nikolaevsky’s plasticity model (non-associated plastic flow rule with the plasticity criterion in the form of Mises–Schleicher). We verified the model and determined its parameters by the example of high-strength concrete. The developed dynamic model can be implemented within the framework of various Lagrangian numerical methods (including finite and discrete element methods) using an explicit integration scheme.

The importance of the wind tunnel facilities in the aeronautical and space industry is crucial because an experimental test campaign could provide a precise overview of the aerodynamic loads in free-stream conditions of studied vehicle. In order to provide accurate and reliable results coming from the wind tunnel, an appropriate post processing is required. Over the time, the subject of the Wind Tunnel Data Corrections has been treated by many authors. The most important corrections are related to the presence of the walls of the test section and the presence of the sting (adaptor) which connect the model with the pitching system of the wind tunnel. All these interferences (due to presence of walls test section and sting) induce different boundary conditions of the flow compared to the free-stream conditions. The general idea in most papers is to apply corrections using classical methods derived from potential flow theory (available just for subsonic flow regimes in either solid walls or open test section), or using the numerical methods, like panel or CFD techniques (valid for all flow regimes) replicating as close as possible the test configuration and condition. Nowadays, the numerical methods are preferred for all regimes due to increased accuracy given by the higher computational capabilities and development of adequate models and algorithms. The purpose of the present paper is to describe the procedure of applying of the corrections to the wind tunnel data (aerodynamic coefficients) adopting the CFD techniques using the commercial solver Fluent, for a slender body.

This paper deals with the numerical investigation of ellipticity of the boundary value problem for isothermal finite strain elasto-plasticity. Ellipticity can be lost when softening occurs. A discontinuity surface then appears in the considered material body and this is associated with the ill-posedness of the boundary value problem. In the paper the condition for ellipticity loss is derived using the deformation gradient and the first Piola-Kirchhoff stress tensor. Next, the obtained condition is implemented and numerically tested within symbolic-numerical tools AceGen and AceFEM using the benchmark of an elongated rectangular plate with imperfection in plane stress and plane strain conditions.

Numerical computation packages are widely used both in teaching and research. These packages consist of license (proprietary) and open source software (non-proprietary). One of the reasons to use the package is a complexity of mathematics function (i.e., linear problems). Also, number of variables in a linear or non-linear function has been increased. The aim of this paper was to reflect on key aspects related to the method, didactics and creative praxis in the teaching of linear equations in higher education. If implemented, it could be contribute to a better learning in mathematics area (i.e., solving simultaneous linear equations) that essential for future engineers. The focus of this study was to introduce an additional numerical computation package of Scilab as an alternative low-cost computing programming. In this paper, Scilab software was proposed some activities that related to the mathematical models. In this experiment, four numerical methods such as Gaussian Elimination, Gauss-Jordan, Inverse ...

This paper reports a new numerical method based on Bernoulli polynomials for the solution of Helmholtz equations. The method uses matrix forms of Bernoulli polynomials and their derivatives by means of collocation points. Aim of this paper is to solve Helmholtz equations using this matrix relations. © 2017 Author(s).

The paper deals with the boiling process mechanism, the results of the boiling intensification methods analysis at subatmospheric pressure are presented. The calculation methodology for the boiling process on the surface performed in the form of capillary slotted channels is represented. Heat transfer coefficients variations calculation dependences defined by analytical and numerical methods applying are described. The heat exchange surface geometrical characteristics impact on the heat exchange capacity in vacuum conditions was investigated.The paper deals with the boiling process mechanism, the results of the boiling intensification methods analysis at subatmospheric pressure are presented. The calculation methodology for the boiling process on the surface performed in the form of capillary slotted channels is represented. Heat transfer coefficients variations calculation dependences defined by analytical and numerical methods applying are described. The heat exchange surface geometrical characteristics impact on the heat exchange capacity in vacuum conditions was investigated.

Thermo-mechanical numerical modelling and simulation of extrusion processes faces several serious challenges. Large plastic deformations in combination with a strong coupling of thermal with mechanical effects leads to a high numerical demand for the solution as well as for the handling of mesh distortions. The two numerical methods presented in this paper also reflect two different ways to deal with mesh distortions. Lagrangian Finite Element Methods (FEM) tackle distorted elements by building a new mesh (called re-meshing) whereas Arbitrary Lagrangian Eulerian (ALE) methods use an “advection” step to remap the solution from the distorted to the undistorted mesh. Another difference between conventional Lagrangian and ALE methods is the separate treatment of material and mesh in ALE, allowing the definition of individual velocity fields. In theory, an ALE formulation contains the Eulerian formulation as a subset to the Lagrangian description of the material. The investigations presented in this paper were dealing with the direct extrusion of a tube profile using EN-AW 6082 aluminum alloy and a comparison of experimental with Lagrangian and ALE results. The numerical simulations cover the billet upsetting and last until one third of the billet length is extruded. A good qualitative correlation of experimental and numerical results could be found, however, major differences between Lagrangian and ALE methods concerning thermo-mechanical coupling lead to deviations in the thermal results.

Islamic banking in Malaysia offers variety of products based on Islamic principles. One of the concepts is a diminishing musyarakah. The concept of diminishing musyarakah helps Muslims to avoid transaction which are based on riba. The diminishing musyarakah can be defined as an agreement between capital provider and entrepreneurs that enable entrepreneurs to buy equity in instalments where profits and losses are shared based on agreed ratio. The objective of this paper is to determine the internal rate of return (IRR) for a diminishing musyarakah model by applying a numerical method. There are several numerical methods in calculating the IRR such as by using an interpolation method and a trial and error method by using Microsoft Office Excel. In this paper we use a bisection method and secant method as an alternative way in calculating the IRR. It was found that the diminishing musyarakah model can be adapted in managing the performance of joint venture investments. Therefore, this paper will encourage mo...

This paper summarizes the experimental campaign and numerical analysis performed aimed to analyze the potential benefit available employing a trapping vortex cell system on a high thickness symmetric aero-foil without steady suction or injection mass flow. In this work, the behavior of a two dimensional model equipped with a span wise adjusted circular cavity has been researched. Pressure distribution on the model surface and inside and the complete flow field round the model have been measured. Experimental tests have been performed varying the wind tunnel speed and also the angle of attack. For numerical analysis the two dimensional model of the airfoil and the mesh is formed through ANSYS Meshing that is run in Fluent for numerical iterate solution. In the paper the performed test campaign, the airfoil design, the adopted experimental set-up, the numerical analysis, the data post process and the results description are reported, compared a discussed.

This paper provides an optical characterization and numerical prediction of local deformations appearing on the visible side of composite sandwich panels used for interior furniture of business airplanes. During manufacturing of furniture panels, metallic inserts are bonded inside the sandwich panel using an epoxy adhesive. Surface defects appear on the visible side of the panels due to curing of the adhesive, but also because of temperature gradients and humidity during manufacturing and in service. This paper presents an optical characterization based on deflectometry principle, that allows qualitative and quantitative analyses of the surface deformations in 3-dimensions. In addition, this paper presents a parametric model based on finite elements to predict the formation of surface defects using ABAQUS. A comparison is presented between the experimental observations and numerical predictions with good agreement between them.

The paper deals with buckling and post-buckling behaviour of thin-walled glass reinforced aluminium laminate (GLARE) members subjected to axial loading. Different open cross-section profiles were prepared by autoclave technique that provided a high-quality manufacturing. Symmetrical 3/2 lay-ups were analysed wherein 7 stacking sequences were distinguished based on the fibres alignment in the composite layer. Composite specimens were axially compressed in laboratory tests by means of static testing unit that provided displacement control loading. The behaviour of thin-walled GLARE members was investigated with main focus on post-buckling response together with various failure modes. First Ply Failure (FPF) analysis was carried out simultaneously by Tsai-Wu, Hashin and Puck failure criteria in order to detect a first failure occurrence. Numerical analysis included also an attempt to estimate particular regions of laminate's damage in post-buckling state. Predicted collapsed mode shapes of GLARE members were found to be in a good agreement with experimental results.

The paper presents the research of tension process of elastomeric fiber gained from the Helical Auxetic Yarn structure. Experimental tests of static tension were carried out, and then used for the numerical model validation. Numerical analyses were conducted in the LS-Dyna software using the Finite Element Method. MAT_24_PIECEWISE_LINEAR_PLASTICITY material model, in which a curve from experimental research was implemented, was used. The adopted numerical model showed good compatibility with the results of experimental tests.

The packaging involve package cushioning to protect products from impact damage. The most common protection is trapezoidal cross-section PE foam cushioning. The paper covers the numerical analysis of the effect of the inclination angle of the trapezoidal walls on the maximum acceleration of the dropping platen as a result of impact with cushioning material. The research results show that for the angle of inclination of the side walls up to 15°, a similar product acceleration can be recorded as using the same volume cuboid sample.

In developed countries, shallow geothermal energy piles have become an innovative and sustainable technology in energy geotechnics. However the concept on shallow geothermal energy pile from design solutions, its operations and soil-pile interactions are still less understood. This paper aims to understand the general review on application in energy geotechnic, thermal properties and numerical studies of shallow geothermal energy pile. There are factors that need to be considered in early steps of numerical analysis which are geometry model, input data (thermal and soil properties), boundary conditions, elements discretization and type of analysis. Many previous studies show the three dimensional geometry problems are modelled in finite element computer modelling. Assumptions between soil and pile interaction are made and properties of soil and pile are identified in the studies. Results from previous studies indicate similar conclusion where W-shaped pipe typed configuration from various types of energy pile is the most efficient tool and it supplies moderate flow rate at the reference level.

The paper deals with numerical analysis of the DCB test configuration together with the data reduction scheme described in the ASTM D 5528 Standard for determination of the mode I fracture toughness in case of the laminated composites with mechanical couplings. Numerical analysis based on the FEM approach was performed with the Abaqus software exploiting the VCCT technique. The experiments on the DCB beams made of coupled laminates were also performed. The results show, that the distribution of the Strain Energy Release Rate can be asymmetric. A need for appropriate data reduction schemes has been revealed.

Honeycomb cores used in engineering applications are subjected to compressive and bending loads. One of the most important elastic properties allowing the accurate design of the structural components which contain honeycomb cores is the out-of-plane Young modulus. The present paper provides analytical and numerical analysis, allowing an accurate design of the structural components containing honeycomb cores.

This paper deals with some examples of numerical modelling for ship’s dynamics problems and data comparison with corresponding experimental results. It was considered two kinds of simulation: self-propelled turning motion of crude carrier KVLCC2 and changing position of container carrier S 175 due to wave loadings. Mesh generation and calculation were made in STAR-CCM+ package. URANS equations were used as system of equations closed by k-w SST turbulence model. The vessel had several degrees of freedom, which depend on task. Based on the results of this research, the conclusion was made concerning the applicability of used numerical methods.

This paper presents computational and finite element methods (FEM) to analysis tire and road interaction. Excitation of vibration, rolling resistance, and traction are all attributes of the interaction between tires and road. The geometry and the displacement fields of the tire inner surface are described by Bezier polynomials. The contact constraints, including force constraints and displacement constraints, are directly enforced into the governing equations to reduce the number of unknown variables. It is shown that the footprint shape and the stress distribution in the belts predicted by the present method are very close to the results by Ritz type numerical method.

The paper presents a numerical method for processing a large amount of data in detection of anomalies of the chemical elements distribution in polymetallic deposits. Mathematically, the problem reduces to solving the Fredholm integral equation of the first kind for large number of different right-hand parts, while the kernel remains unchanged. The algorithm consists of two stages: at the first stage a number of problems are solved, for which knowing the right part is not required, in the second stage, the previously obtained data are used to find solutions of the integral equation for different right-hand sides. This approach allows the data processing “in-situ” and to define prospects of the established abnormal areas, allocate the overriding areas for geological exploration. The algorithm is tested on model and real data.

The numerical method to solve multimaterial topology optimization problems for elastic bodies in unilateral contact with Tresca friction is developed in the paper. The displacement of the elastic body in contact is governed by elliptic equation with inequality boundary conditions. The body is assumed to consists from more than two distinct isotropic elastic materials. The materials distribution function is chosen as the design variable. Since high contact stress appears during the contact phenomenon the aim of the structural optimization problem is to find such topology of the domain occupied by the body that the normal contact stress along the boundary of the body is minimized. The original cost functional is regularized using the multiphase volume constrained Ginzburg-Landau energy functional rather than the perimeter functional. The first order necessary optimality condition is recalled and used to formulate the generalized gradient flow equations of Allen–Cahn type. The optimal topology is obtained as...

In this paper some of the important parameters that influence the effectiveness of composite material shaft of high speed rotor-bearing system on rotor dynamics are analyzed. The type of composite material composition, the number of layers along with their stacking sequences are evaluated as they play an important role in deciding the best configuration suitable for the high-speed application. In this work the lateral modal frequencies for five types of composite materials shaft of a high-speed power turbine rotor-bearing system and stresses due to operating torque are evaluated. The results are useful for the selection of right combination of material, number of layers and their stacking sequences. The numerical analysis is carried out using the ANSYS Rotor dynamic analysis features.

The comparison of numerous simulations of the non-equilibrium condensation in nozzles in the frame of recently finished “International Wet Steam Modelling Project” [1] showed a certain spread of results caused not only by used condensation models, but most probably by numerical methods as well. Current condensation models require a fine tuning of some parameters to fit the nucleation onset as well as the correct size of droplets. This fine tuning is very sensitive, therefore the properties of used numerical method play also an important role. Present paper tries to show the effects of discretization, order of method and time integration on the results for several examples of flow with non-equilibrium condensation in nozzle.

International Conference of Numerical Analysis and Applied Mathematics (ICNAAM) -- SEP 25-30, 2017 -- Thessaloniki, GREECE, WOS: 000445105400302, In this paper, we give a generalization of absolutely almost convergence, and prove interesting results.

The paper proposes a method of numerical study of heat exchange and temperature fields of self-lubricating cooled turbocharger bearing, the cooling system of which is implemented by the type of “water jacket” on the basis of ANSYS CFX package. To verify the heat exchange in the cooling channel of the bearing, an experimental stand was developed and tests were carried out. The results obtained by numerical and experimental methods have a good correspondence, which confirms the possibility of using the numerical method for solving engineering problems associated with the design of the cooling system of such a bearing.

The Rim-driven Thruster (RDT) integrates the thrust motor and the propeller, which can effectively reduce the space occupied by the propulsion system, improve the propulsion efficiency, and thus has important research value and broad market prospects. The Halbach Permanent Magnet Rim Thrust Motor (HPMRTM) can improve the torque density of the propulsion motor by utilizing the unilateral magnetic field of the Halbach array. In this paper, the numerical method is used to study the electromagnetic performance of the motor under different Halbach array parameters. The relationship between motor parameters such as air-gap flux density, electromagnetic torque and Halbach array parameters is obtained, and then the motor structure is optimized. By comparing with Common Permanent Magnet RTM, the advantages of HPMRTM are verified.

The paper presents the results of testing the strength of butt joints welded with the GMAW method. The base material of the joints was high-strength ferritic steel. The research program included experimental and computational part. In experimental studies, precise hardness distribution measurements were carried out to determine the extent of zones in joints. On the basis of the hardness of the material, its strength characteristics were defined in the relevant sections of the welded joint analyzed. Defining material properties and geometry of zones allowed to create a numerical model of the specimen. Based on the numerical analysis of the specimen load, the most stressed areas in the welded joint were determined. The results of numerical computations were verified by experimental methods. The correctness of the numerical model was checked by comparing the strain distributions on the surface of the specimen obtained FEM and measured using the Aramis video system.

The following paper presents numerical analyses and laboratory tests used for analyzing the impact of exploitation damage to the main structural members of the scaffolding frame system. The presence of inevitable defects reduces the strength of material compared to the theoretical strength. Numerical analysis preceded by own laboratory research allows you to describe precisely the behavior of the element. Performing a series of calculations gives information on the impact of the damage size and location on the bearing capacity of the scaffolding frame.

We have worked on the development of a particle-based numerical model of a hydrogen Radio Frequency (RF) Inductively Coupled Plasma (ICP). In the previous work, it has been shown that the model is able to simulate the E-to-H discharge mode transition, which is one of the distinct features of RF ICP. The purpose of the present study is to investigate the E-to-H discharge mode transition of the hydrogen RF ICP by our numerical model. In particular, the spatiotemporal behavior of ions, which we have not investigated in the previous work, will be presented in this paper.

If nuclear fuel melts due to the loss of cooling, hydrogen is generated by chemical reaction of metallic clad with steam, resulting in the hydrogen risk of explosion. Therefore the stratification of hydrogen in the steam-air environment is important, which is influenced by the steam condensation. In this paper, we explored physical parameters which may affect the hydrogen stratification under steam condensation conditions through benchmarking process with a small-scale experiment using a Computational Fluid Dynamics (CFD) code, in order to identify relative influences of numerical model parameters on the stratification analysis.

The numerical equilibrium path analysis of the material with random rheological properties by using standard procedures and specialist computer programs was not successful. The proper solution for the analysed heuristic model of the material was obtained on the base of chaos theory elements and neural networks. The paper deals with mathematical reasons of used computer programs and also are elaborated the properties of the attractor used in analysis. There are presented results of conducted numerical analysis both in a numerical and in graphical form for the used procedures.

The main aim of this paper is an experimental and numerical analysis of the dynamic behavior of an active rotor with three composite blades. The study focuses on developing an effective FE modeling technique of a macro fiber composite element (denoted as MFC or active element) for the dynamic tests of active structures. The active rotor under consideration consists of a hub with a drive shaft, three grips and three glass-epoxy laminate blades with embedded active elements. A simplified FE model of the macro fiber composite element exhibiting the d33 piezoelectric effect is developed using the Abaqus software package. The discussed transducer is modeled as quasi-homogeneous piezoelectric material, and voltage is applied to the opposite faces of the element. In this case, the effective (equivalent) piezoelectric constant d33* is specified. Both static and dynamic tests are performed to verify the proposed model. First, static deflections of the active blade caused by the voltage signal are determined by num...

International Conference of Numerical Analysis and Applied Mathematics (ICNAAM) -- SEP 25-30, 2017 -- Thessaloniki, GREECE, WOS: 000445105400303, In this paper, the concept of a strongly lacunary delta(2) quasi-Cauchy sequence is introduced. We proved interesting theorems related to strongly lacunary delta(2) -quasi-Cauchy sequences. A real valued function f defined on a subset A of the set of real numbers, is strongly lacunary delta(2) ward continuous on A if it preserves strongly lacunary delta(2) quasi-Cauchy sequences of points in A, i.e. (f(alpha(k))) is a strongly lacunary delta(2) quasi-Cauchy sequence whenever (alpha(k)) is a strongly lacunary delta(2) quasi-Cauchy sequences of points in A, where a sequence (alpha(k)) is called strongly lacunary delta(2) quasi-Cauchy if (Delta(2)alpha(k)) is a strongly lacunary delta(2) quasi-Cauchy sequence where Delta(2)alpha(k) = alpha(k+2)-2 alpha(k+1)+ alpha(k) for each positive integer k.

The numerical analysis of thermal damage process proceeding in biological tissue during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional. The internal heat source resulting from the laser irradiation based on the solution of diffusion equation is taken into account. The tissue is regarded as a homogeneous domain with perfusion coefficient treated as dependent on tissue injury. At the stage of numerical computations the boundary element method and the finite difference method have been used. In the final part of the paper the results obtained are shown.

The thermal insulation known types efficiency and applicability theoretical comparative analysis taking into account the mobile compressor units recovery systems typical modes was conducted in the paper. The study was carried out by means of the numerical method through the heat transfer processes modelling of the system «heat carrier – wall – hot gas – wall – insulation - environment», i.e. in the recuperative heat exchanger simplified version. The three most common types of insulation: foamed and fiber thermal insulation materials and vacuum insulation were applied as the heat exchanger external insulation.

Model high-speed combustor on gaseous hydrocarbon fuel, prepared for experiments in T-131 wind tunnel of TsAGI, is presented. Experiments are projected to create an experimental database for validation of calculations and physical models of turbulence and combustion. Geometry of combustor and prepared measurements are described. The main subject of paper is preliminary calculations of this combustor. Numerical methods for 2D and 3D URANS calculations are described. Special attention is given to numerical techniques allowing fast calculations of 3D unsteady flow development in the combustor. Approach to parallel realization of Fractional Time Stepping (FTS) technology is described. One way of In Situ Adaptive Tabulation (ISAT) of kinetic equations solution during the calculation is presented. Possible gasdynamic structure of flow in the combustor with the flame stabilization both in subsonic and in supersonic regime is described. Asymmetrical stationary solution (for the symmetrically-expanding duct) and symmetrical solution with flame oscillations are found and analyzed.

The project is the study of the thermal drilling process. The process is a hole forming process in the sheet metals using the heat generated by means of friction. The main advantage of the process over the conventional drilling process is that the holes formed using this process does not need any backing arrangements such as weld nuts, rivet nuts etc. Because the extruded bush itself acts as a supporting structure for the fasteners. This eliminates the need for the access to the backside of the work material for fastening operations. The major factors contributing the thermal drilling operation are the spindle speed and the thrust force required for forming a hole. The process of finding out the suitable thrust force and the speed for drilling a particular material with particular thickness is a tedious process. The process can be simplified by forming a mathematical model by combining the empirical formulae from the literature. These formulae were derived in the literature from the experimental trials by following certain assumptions. In this paper a suitable mathematical model is formed by replicating the experiments and tried to be validated by the results from numerical analysis. The numerical analysis of the model is done using the ANSYS software.The project is the study of the thermal drilling process. The process is a hole forming process in the sheet metals using the heat generated by means of friction. The main advantage of the process over the conventional drilling process is that the holes formed using this process does not need any backing arrangements such as weld nuts, rivet nuts etc. Because the extruded bush itself acts as a supporting structure for the fasteners. This eliminates the need for the access to the backside of the work material for fastening operations. The major factors contributing the thermal drilling operation are the spindle speed and the thrust force required for forming a hole. The process of finding out the suitable thrust force and the speed for drilling a particular material with particular thickness is a tedious process. The process can be simplified by forming a mathematical model by combining the empirical formulae from the literature. These formulae were derived in the literature from the experimental trials by...