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Background: COVID-19 has become a global concern as it has ended the lives of lakhs of people. The study done by. Lin proposed the results of an analysis of a theoretical computational model of epidemiology taking into account the crucial components such as response of an individual behavior, measures taken by government, rapid transmission and emigration of fever virus to a huge extent of human population. Simple model framework has been used by them to examine the requirements of essential elements.Problem: We claim the perfect validation of the assumptions stated for the purpose of modeling and its analysis, however, the analytical solution of the presented model is not discussed. And thus have a poor potential to make computational estimates.Methodology adopted: We have tried to present and validate the mathematical/analytic solution of the developed model, considering their assumptions.Conclusion: We have reached to the outcome that the work presented by Q. Lin should be demonstrated adequately with a cautionary advice of not to consider the results and analysis of such numerical models.The current study proposed the results of an analysis of a theoretical computational model of epidemiology taking into account the crucial components such as response of an individual behavior, measures taken by government, rapid transmission and emigration of fever virus to a huge extent of human population. Simple model framework has been used by them to examine the requirements of essential elements. We claim the perfect validation of the assumptions stated for the purpose of modeling and its analysis, however, the analytical solution of the presented model is not discussed. The decision point of this work is to adequately demonstrate along with the cautionary advice of not to use the outcomes and analysis of such numerical models. [ABSTRACT FROM AUTHOR]

In this paper we study the preservation of Lyapunov functions in the numerical integration of ordinary differential equations. By means of a continuous extension and a projection technique we extend the technique proposed by Grimm and Quispel (BIT 45, 2005), so that it can be applied to other families Runge—Kutta methods such as the well known Dormand and Prince 5(4) pair. [ABSTRACT FROM AUTHOR]

In the paper considers a discrete model of SIRD, constructed on the basis of discrete Lotka-Volterra dynamical systems operating in a three-dimensional simplex with a degenerate skew-symmetric matrix. The sets of ignition and the end of the epidemic have been found, and the sets where the population is dying out have been found. The paper also provides a numerical analysis of the proposed model. [ABSTRACT FROM AUTHOR]

In this paper an EPQ model is studied for deteriorating items with non linear price and stock dependent demand under the effect of inflation. Most of the inventory model considers holding cost assumed constant but in real situation it depends on time. Therefore holding cost assumed as a function of time. Shortages are taken partially backlogged type with fixed backlogging rate. The main objective of this proposed paper is to obtain the optimal solution. The numerical analysis has been also done to verify the initiated paper. Finally, a sensitivity analysis is also made for different parameters to obtain some useful observations. [ABSTRACT FROM AUTHOR]

Information about the third symposium on Recent Trends in the Numerical Solution of Differential Equations is presented. Topics include numerical methods for eigenvalue problems and analysis of boundedness of general linear methods. In addition, the event highlighted various studies including the use of the well-known technique of defect correction and a new practical strategy to detect stiffness based on explicit Runge-Kutta schemes.

The development of modern society is conditioned by the accelerated pace of development of technological awareness. Our urban environment is increasingly exposed to radical transformations, leaving no room for perception and adoption of the new, almost excluding the feeling of belonging to the transformed environment. Such changes, caused by the expansion of construction activity, often violate the ambient and original values, in the transformed environments of "captured" cultural and historical heritage Objects of cultural and historical heritage possess historical, artistic and aesthetic value, readability in all their historical changes and the symbolic value of the tradition of the society to which they belong. Preservation of spiritual, formal and traditional originality, with all the technical characteristics they carry with them, emphasizing the uniqueness and representativeness of heritage in a modern environment, is an imperative in preserving one's own identity. The constructive characteristics of the historical heritage building were dictated by the degree of technical knowledge, experience and intuitiveness of the builders of that time. The specificity of structural systems and construction techniques have a direct impact on the architectural character of buildings, and thus the approach to structural repair, considering the problem exclusively from the point of view of structure and application of modern methods of numerical analysis and technology, can be a cause of disavowal of these buildings.Thus, questions arise: How sovereign are new knowledge and methods over the old, or is it necessary to awaken the intuitiveness of today's builders? How to achieve compatibility of old and new, where necessary? In this paper, the case study of a specific sample of the cultural and historical heritage of Despic House will provide answers to the questions asked. Despic House, where the first theatre in Sarajevo was founded, is one of the few material evidences of life in the city at the turning point of the Ottoman and Austro-Hungarian periods. Atypical in relation to the local way of building, it is a unique example of a combination of the traditional heritage of the Ottoman period and the " breakthrough of European creativity into the culture of this area". This paper presents a complex research process of establishing the genesis of the Despic House, as well as the consequences of the influence of urban transformations in the spatial framework at the level of the architectural object and the level of the urban-architectural ensemble. On the example of established and implemented measures of structural repair of this building, the importance of a multidisciplinary approach to detailed research and conservation-restoration works for cultural and historical heritage buildings will be confirmed, taking into account its original values. [ABSTRACT FROM AUTHOR]

The present paper analyzes failure observed in polymer rods collided with a steel anvil under the Taylor cylinder impact experiments. The experimental and numerical analysis demonstrates that association of the failure patterns with the loading mode depends on the rod material. Two materials are considered in the paper, specifically, polymethylmethacrylate (PMMA) and polycarbonate (PC). Damage in PMMA rods at the Taylor tests is shown to be dominated by the shear load resulting in plastic deformation. In contrast, the major mechanism of damage in PC rods is governed by omni-directional (pressure) mode of load. Analysis of the damage in sections of the rods associated with the glass transition is also addressed in the present theoretical study. Failure in these polymers follows the traditional fracture wave mechanism for brittle glass-type materials due to load in the corresponding mode. Numerical analysis employs a two-phase model with improved inter-phase thermal balance accounting for the inter-phase mass, momentum, and heat exchanges during the glass phase transition, while damage being accumulated in time. The simulation results demonstrate a good correlation with the experimental results. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of load-bearing capacity and deformability of wood-steel hybrid systems, depending on the selected system constellation, and the possibility of increasing system efficiency and in real conditions by applying pre-stress, in accordance with modern principles of structural conceptual design. The subject of the research is the behaviour of pre-stressed glued laminated beams with external polygonal ropes, different researched constellations, i.e. strut type hybrid systems, in real conditions. The paper is practically divided into three methodological units: theoretical and numerical analysis, and examples of practical applications, and on the theoretical basis of urban transformations of historical units. Theoretical assumptions, as well as the current and own approach to the analysis of parameters, set the theoretical basis for the analysis of these systems and the possibility of applying numerical methods in practice. Parametric analysis of the hybrid system obtained practical expressions and diagrams for use in practice, needed to determine suitable constellations of strut type hybrid system by different geometric characteristics and pre-stressed hybrid system, and for different percentages of wooden girder moisture. In order to compare these systems, the same assumptions were used for the calculation, namely: plane behaviour of the system, and to determine the effective pre-stressing, the condition of annulment of vertical deflection in characteristic cross-sections was used, i.e. achieving the effect of vertical immobility of the struts, from which the measure of pre-stressing of the deformable system was obtained. A hybrid system with a wooden girder, which has bending stiffness, is often used in construction, and the main disadvantage of such a system is the expressed deformability in real operating conditions. The basic thesis of this paper is that by external pre-stressing of glued laminated girder achieves less deformability and increases bearing capacity, while saving base material in real conditions, and is confirmed by our own parametric analysis and laboratory testing of pre-stressed hybrid systems of different constellations. The attached parametric analysis diagrams provide a sufficiently accurate orientation for finding the correct constellations of wood-steel hybrid systems and the possibility of estimating the efficiency of hybrids in real conditions, as well as the necessary pre-stressing applications. The derived expressions of the approximate procedure and the expressions for finding the effective pre-stressing force, assuming the linear behaviour of the system, give sufficiently accurate results for the design of pre-stressed hybrid systems in practice. Also, with this or similar methodology it is possible to qualitatively investigate hybrid systems with different combinations of materials. The presented conceptual solutions for the integration of hybrid systems and modern materials in specific localities represent a contribution to the development of a methodological approach to the transformation of historical urban units. [ABSTRACT FROM AUTHOR]

In this paper, buckling analysis of composite stiffened panel with different shapes stiffener under uniaxial compressive load was carried out. Buckling behavior of straight stiffened panel on different shape of stringers were studied and compared. Stiffeners are providing the stiffness to the stiffened panel. In this paper several types of shapes like Z- shape, L-shape, Hat shape, I-shape, C-shape, J-shape and T- shape were taken. Numerical analysis done by non- linear software (ABAQUS 6.14-1). Main motive of this paper understands the shape of stringers and influences of the shapes in buckling strength. Influences of stiffener with various cross section areas of stiffened panel were deciding the buckling strength of the panel. Once buckling strength was improved, relatively high stiffness of assembly is also improving. Closed sections and more fasteners providing high buckling loads. [ABSTRACT FROM AUTHOR]

The presence of lead material in lead halide perovskite absorber is always remains a major obstacle due to its toxic nature. The emergence of tin halide perovskite absorber will overcome this toxicity issue and due to its extraordinary properties such as direct band gap and compatible visible spectrum of solar cells attracts a wide attention to researchers to focus on the development of lead free perovskite solar cells. This paper comprises of the device simulation of lead-free perovskite material. In addition, effect of various hole transport layers, and the effect of absorber band gap have been studied. It has been observed from the results that along with the proper band alignment of HTM layer with perovskite layer, the mobility of HTM layer plays an important role to achieve better device performance. Furthermore, it has been concluded that Cu2O layer as a hole transport material exhibits better device performance as compare to the other HTM layer used in this paper. [ABSTRACT FROM AUTHOR]

Information about the Recent Trends in the Numerical Solution of Differential Equations second symposium is presented. Topics discussed include the numerical method of Hamiltonian problems, new definition of stiffness with applications and numerical methods for variational inequalities. The meeting featured several mathematics experts, including L. Aceto, L. Brugnano and R. Lamour.

Functionally Graded Materials (FGMs) is a new composite material with gradients of material composition. The FGMs introduce by scientists from Sendai, Japan. The properties of FGMs used in this paper are metal and ceramic. Metal is a material that is resistant to structural flexibility, while ceramic is a material that is resistant to high temperatures. This paper presents the free vibration of FGMs beams using the Mixed Quadratic Beam (MQB) element. This paper begins with the formulation of the MQB element, then followed by numerical analysis of free vibration on FGMs beams problems. Free vibration analysis of FGMs beams is done by solving a simple supported (SS) beam with L/h=5. The results are compared to the reference solution. From the analysis, it can be concluded that the MQB element shows promising results for beams with a large number of elements. [ABSTRACT FROM AUTHOR]

The impact of physical loads in the automotive assembly line has been investigated in the automotive and manufacturing industries. The purpose of this paper is to systematically examine the impact of human factors on worker quality performance in designing and managing manufacturing operations. Tiredness and efficiency deficits have a good relationship. Thus, the display of fatigue graphs, and S-N curve about overloading, heavy manufacturing work in industry depicts stress and fatigue are inversely proportional to the number of cycles. Also, the authors determine the fatigue limit numerically by calculating the r-ratio or amplitude ratio. Data was collected from the rail coach factory, Kapurthala using a particular database system. [ABSTRACT FROM AUTHOR]

Today, the study of the distribution of emissions in the atmosphere is quite an urgent task, because harmful substances, getting into the surrounding atmosphere, cause harm to the health of people, flora and fauna. In this paper, the results of simulation of the distribution of emissions from the Ekibastuz TPP (GRES 1) are presented. For simulations the model of turbulence was chosen. Simulations were performed by using the ANSYS 16.0 software package. Previously, the model and numerical algorithm were tested using a model problem and the results were compared with the experimental data. [ABSTRACT FROM AUTHOR]

The Rim-driven Thruster (RDT) is a new type of marine electric thruster proposed in recent years. In this paper, the author proposed a new type of permanent magnet synchronous rim thrust motor (RTM). The motor uses a Halbach array permanent magnet rotor, which can improve the torque density of the propulsion motor by utilizing the unilateral magnetic field of the Halbach array.In this paper, the electromagnetic properties of the motor were measured and compared with that of the ordinary magnetic pole motor through numerical analysis. The results show that at the same power, the new motor can significantly reduce the thickness of the rotor's permanent magnet and yoke core, and has obvious advantages in power density, moment of inertia, dynamic performance, and cost. [ABSTRACT FROM AUTHOR]

Theoretical analysis to predict the crack propagation of Al 2024 is required and validated by experiment. This theoretical analysis was developed through a mathematical model that is based on the development of the Paris equation. The Paris equation is used to analyze crack propagation against a constant amplitude load. In this paper, a mathematical model based on the Paris equation is developed for the load spectrum, where the effective results are obtained at stage 2 when conditions are stable. The results of the development of this mathematical model are quite promising to be used as a reference for further experiments with the same material [ABSTRACT FROM AUTHOR]

This paper deals with a slat chain conveyor for the transport of rock materials in very severe abrasive conditions. An actual case from practice is discussed and analysed. To clarify the fatigue damage of the chain link material, the finite element method (FEM) is applied. For the experimentally recorded cycle of chain loading, numerical analysis has been performed and data for the damage of the link material are presented. Fatigue analysis is performed by ANSYS nCode DesignLife under different loading cases. FEM results show, that the fatigue crack of the link starts from region with high values of the stresses, established by experiment. [ABSTRACT FROM AUTHOR]

A finite element analysis on crash box of an automotive bumper system is presented in the paper to investigate the energy absorption of the component with and without foam-filled steel sheet metal tubes of different thicknesses for crashing or low-velocity impact analysis. The energy absorption capacity of the crash box for crashing is evaluated for different design changes of the foams-tube structure and compared the results without foam. By changing the different foam materials, various designs are proposed and simulated for maximum energy absorption. Altair Hyperworks is used for preprocessing and post-processing and Radios solver is used to run the analysis. A reasonable agreement is obtained in the results of the analytical and numerical methods. The results indicate that the energy absorption of a foam-filled crash box structure is superior to the crash box without foam. [ABSTRACT FROM AUTHOR]

The main idea of this paper is to give a profound investigation of the aerodynamic properties of a wing for Cessna 172S. The numerical analysis of total drag is developed by using various methods from different references, the 2D and 3D lift curve parameters of the wing Cessna 172S are generated according to the analysis method depending on empirical equations. The first stage of modelling Cessna 172S is evaluated according to the airfoil of Cessna NACA 2412, whereas the second stage of modelling is estimated by using wing planform properties. The maximum lift coefficient, lift curve slope, zero angle of attack, lift at zero angle of attack, and stall angle of attack are calculated by using different empirical equations. [ABSTRACT FROM AUTHOR]

Texture masking has been used as a significant factor in creating perceptual maps that simulates human vision system in observing noise in digital images. In this paper, the possibility of creating texture masks using first and second derivatives is investigated and tested. Results shows that after applying the derivatives, areas of higher texture were highlighted and recognized, which will lead to simple implementation of texture masks using numerical analysis. [ABSTRACT FROM AUTHOR]

Fourteen airfoils were selected in this research paper to build and optimize a small horizontal axis wind turbine for a low wind speed. By using Q-blade software and CFD simulations for a 0.5 m rotor radius and the tip speed ratio ranged from 3 to 10. In this paper selected airfoil such as E205, E214, E216, NACA2412, NACA4418, SG6040, SG6041, SG6042, SG6043, S1221, S2091, S7012, SD7034 were investigated. As the most suitable geometries, Airfoil E216 and SG6043 cast out by checking numerical simulations to gain more power at low Reynolds number. In this study comparing the drag coefficient, lift coefficient and lift to drag ratio with respect to angle of attack, the airfoil has been revised. A parametric optimization of the blade geometry and develop the new airfoil for small wind turbine rotor. The E216 airfoil is found to be better performance with below solidity of8.25%, while the NACA 2412 produces stronger solidityof 21.6% due to wake effects produced behind the rotor. A wind tunnel test, Q-Blade simulation and CFD analysis were performed on the design and optimized for the proposed small horizontal wind turbine rotor axis in order to apply low wind speed area. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The traditional Canny algorithm has poor self-adaptability threshold, and it is more sensitive to noise. In order to overcome these drawbacks, this paper proposed a new edge detection method based on Canny algorithm. Firstly, the media filtering and filtering based on the method of Euclidean distance are adopted to process it; secondly using the Freichen algorithm to calculate gradient amplitude; finally, using the Otsu algorithm to calculate partial gradient amplitude operation to get images of thresholds value, then find the average of all thresholds that had been calculated, half of the average is high threshold value, and the half of the high threshold value is low threshold value. Experiment results show that this new method can effectively suppress noise disturbance, keep the edge information, and also improve the edge detection accuracy. [ABSTRACT FROM AUTHOR]

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 more companies to use the concept of joint venture in managing their investments performance. [ABSTRACT FROM AUTHOR]

The general formula proposed by Landes and Begeley [1], which has been modified for years, among which more or less complicated approaches can be distinguished for determining the J-integral in laboratory conditions. One of them is the ASTM standard [2], according to which the energy required to calculate the J-integral should be decomposed into elastic and plastic parts, and thus the factor η depending on the shape of the specimen used in laboratory tests. Some approaches, e.g. the Polish standard [3], indicate that the J-integral should be calculated without decomposing into elastic and plastic parts. The normative documents mentioned do not usually mention the dependence of the η factor on the geometrical dimensions of the specimen (except for the shape of the specimen) or the dependence on the material characteristics. As shown in [4-7], the value of the coefficient η depends on the crack length and the material characteristics, however, the influence of material constants is usually discussed in a strictly defined range. It should be noted that papers [4-7] are based on the decomposition of the coefficient η value into elastic and plastic parts. The hybrid method presented in [8] for assessing selected parameters of fracture mechanics, referring to EPRI procedures [9], allows to evaluate them without the need for tedious numerical calculations, however, unlike EPRI procedures, it does not introduce the need to decompose these parameters into elastic and plastic components. In view of this fact, in this study it was decided to assess on the basis of numerical calculations carried out for the dominance of plane strain, the effect of crack length and material constants (expressed in yield strength and strain hardening exponent in R-O law) on the value of the coefficient η which is required to estimate the value of the J-integral in accordance with by Landes and Begeley [1]. The discussion presented in [10] was the inspiration to undertake this topic. In this paper, based on a comprehensive numerical analysis of SEN(B) specimens dominated by a plane strain state, for four different crack lengths and sixteen hypothetical elastic-plastic materials (characterized by different yield strength and different level of stain hardening exponent), the values of the J-integral were estimated, the impact of the crack length and material constants on the value of J-integral was assessed, an analysis of the P=f(u) curves and discussion on the effect of crack length and material constants on the value of the factor η were presented. Using the approach given in [4-7], simplification was made in the analysis and the value of the coefficient η was determined for each analysed specimen. The analysis showed a strong dependence of the coefficient η on the crack length and the strain hardening exponent n. It turned out that the coefficient η does not depend on the yield strength of the specimen material. The results were summarized in tabular form and approximated using the Table Curve 3D program. The measurable effect of the paper is a summary of numerical results – values of the coefficient η for 64 SEN(B) specimens and a new form of the function η=f(a/W, n) which was proposed, and which allowing to take into account in the process of determining the J-integral by the factor η the geometry of the specimen (relative crack length a/W) and material characteristics (n – strain hardening exponent in R-O law). [ABSTRACT FROM AUTHOR]

An unmanned aerial vehicle (UAV) that is able to take-off and land on a medium sized ship, have greater endurance and range as compared to the previous iteration, and the ability to achieve all three flight modes - vertical, transition and horizontal flight modes is to be designed, built and tested. In this paper a comprehensive review is given on various VTOL planform configuration and a tilt-rotor configuration is selected for Minerva 2.0 for its high stability and increased efficiency. This paper covers the selection analysis of different vertical take-off and landing (VTOL) airframe as well as mechanical and electronic hardware design with the intention of increasing flight efficiency for surveillance purposes on wide sea area. This paper presents Minerva 2.0, a novel aerial platform with VTOL capabilities. Numerical and analytical analysis results are discussed. The previous iteration, Minerva 1.0 was built and tested as a QuadPlane configuration and an increased efficiency of 25 to 58.7% is achieved in this paper. [ABSTRACT FROM AUTHOR]

This paper is devoted to numerical analysis of plaster detachment and numerical experiments for determination of the appropriate material parameters. Interaction between the plaster and masonry is described with the help of interface finite elements which are equipped with traction-displacement relationship. Laboratory tests were introduced in order to determine the shear capacity of the masonry-plaster connection. Unfortunately, variability of measured behaviour was very large and additional tests are needed. [ABSTRACT FROM AUTHOR]

The article discusses various reports published within the issue, including one on parallel approach in solving differential equations and another on high-order block methods.

This paper presents the numerical method applied to predict the performance and wave wash of the river craft. In recent years fast ferries have been introduced on many ferry routes all over the world. Mainly when operating in shallow waters and near the coast, the waves generated by these crafts give escalate to clash with recreational use of beaches and coastal waters. The performance of HSC vehicle in these areas and the potential coastal erosion caused by a changed wave impact has been a subject of concern. In this paper, a finite volume method (FVM) and RANS approach was applied to investigate the wave wash, resistance, trim, and pressure acted on the craft. Actually a dynamic mesh with two degrees of freedom was used and the results were compared with a markedly proper experimental results and the competency of applied method was proved. [ABSTRACT FROM AUTHOR]

This paper presents a study of rarefaction effect on hypersonic flow over a sharp leading edge. Both continuum approach and kinetic method: a widely spread commercial Computational Fluid Dynamics-Navior-Stokes-Fourier (CFD-NSF) software - Fluent together with a direct simulation Monte Carlo (DSMC) code developed by the authors are employed for simulation of transition regime with Knudsen number ranging from 0.005 to 0.2. It is found that Fluent can predict the wall fluxes in the case of hypersonic argon flow over the sharp leading edge for the lowest Kn case (Kn = 0.005) in current paper while for other cases it also has a good agreement with DSMC except at the location near the sharp leading edge. Among all of the wall fluxes, it is found that coefficient of pressure is the most sensitive to rarefaction while heat transfer is the least one. A parameter based on translational nonequilibrium and a cut-off value of 0.34 is proposed for continuum breakdown in this paper. The structure of entropy and velocity profile in boundary layer is analyzed. Also, it is found that the ratio of heat transfer coefficient to skin friction coefficient remains uniform along the surface for the four cases in this paper. [ABSTRACT FROM AUTHOR]

The main purpose of the suspension system is to absorb the vibrations from wheels. To compromise between the two conflicting criteria i.e. road holding and ride comfort, passive suspension system is most suitable. The passenger discomfort is caused due to unwanted vibrations which are transmitted through unsprung mass. The numerical analysis using Simulink MATLAB software is used to determine Ride comfort of two suspension systems based on quarter car model. The experimental setup is developed and vibration analysis is performed using multichannel FFT analyser. The mathematical analysis result of the two different models of the suspensions is compared with experimental analysis. The aim of paper is to investigate effect of sprung mass on ride comfort at constant speed with input 0.1m peak stroke which generated a waveform resembling to half sine wave. The mathematical model is developed and analysed in Simulink MATLAB software. [ABSTRACT FROM AUTHOR]

In our models we assumed that all objects are of good quality. This is possible only under very impractical conditions but actually this is not possible. This paper deals with a two level supply chain Management for fault items. To certify orders, the producer offers some facilities to the retailer such as trade credit for some part of the order, free shipping on the basis of advance payment amount. Enlargement cost is taken as a function of time to keep the fulfillment of the manufacturing system. To find optimum profit we use fuzzy Monsoon demand without shortage. Screening process is also considered to identify whether the formed items are perfect or imperfect. In this paper we derive some useful algorithms to find the optimal solution. Moreover, sensitivity analysis and numerical analysis are made to justify the optimum solution. [ABSTRACT FROM AUTHOR]

The basic function of the gas turbine blades is to rotate the shaft connected to the generator motor. In electricity generation station, because the materials used in manufacturing must resist harsh working conditions, gas turbine blades are subject to high vibration, pressure and temperature. In this paper, the maximum pressure and deformation are caused by the effect of centrifugal force on the gas turbine blades. And to determine the natural frequencies of vibration, which are caused by the rotation speed about 3000 r.p.m under high-temperature conditions. The finite element method (FEM) was used to determine the natural frequency of turbine blade material (GTD-111) applied in the South Baghdad Power Station in Iraq, Baghdad. This paper deals with the structural analysis of gas turbine blades. Analysis was performed to find out the mechanical stresses and radial elongation to which the gas turbine rotor blade is subjected. A solid turbine blade model is constructed using the SOLIDWORKS2018 software. The turbine blade is analyzed for its structural performance due to the loading conditions using ANSYS 19 software to study the stress variation on the GTD-111 alloy gas turbine blades. The results shows that under static load and the stress and strain on the blade, the amplitude of the blade vibration will change at the higher frequencies of 581.42 Hz and 935.84 Hz because the root of the blade is placed on the disk-like cantilever (girder fixed at only one end). [ABSTRACT FROM AUTHOR]

One of the most common problems with quasi-Newton methods is how to select the suitable quasi-Newton equation while operating the algorithm. In this paper, a new modification Quasi-Newton equation is proposed based on recent quasi-Newton equation of the Biglari et.al. method. Theoretical analyses and numerical computations using standard functions, as well as comparison with Broyden-Fletcher-Goldfarb-Shanno (BFGS) show that the proposed new type is globally convergent and computationally efficient. [ABSTRACT FROM AUTHOR]

The following paper aims to provide a detailed analysis of the effect of different cutting speeds in the face milling of AISI 1045 steel using coated tool. Simulations would aid in solving problems associated with experiments, leading to reduced costs and risks. DEFORM 3D is a commercially used simulation software capable of implementing machining simulations using the theory of finite element modelling. A conventional DEFORM 3D milling model has been prepared for the analysis of cutting forces and chip formation and the simulation has been carried out for two conditions. The temperature and force parameters were analyzed after carrying out the experiment and simulation under the influence of different machining and environmental conditions. The results of the simulation revealed that the predicted values of FEA possess good accuracy. [ABSTRACT FROM AUTHOR]

Steel coupling beam is a substantial member in hybrid coupled walls system that greatly enhance the strength and the energy dissipation capacity of the system compared to coupled walls linked by convention reinforced coupling beams and diagonally reinforced coupling beams. To enhance these characteristics even more, a corrugated web may be used instead of the traditional flat web. This paper presents a numerical analysis using finite elements software (ABAQUS) to investigate the nonlinear behavior of both types of steel coupling beams (with flat web and with corrugated web). The effect of initial imperfection on the nonlinear behavior of steel coupling beams was taken into account. The results were compared with the available experimental data of steel coupling beams with the flat web. Good agreement was noticed between the experimental and the numerical results. Among the conclusions drawn in this study is that using a corrugated web as an alternative to a flat web may increase both the strength and the energy dissipation of the steel coupling beams. [ABSTRACT FROM AUTHOR]

Pre-impregnated materials (Prepregs) have greatly impacted many industries that require specific advanced composites, such as aerospace structures for UAVs. Prepreg material aids the structure by reducing weight while increasing strength and allowing for reasonably consistent manufacture. One of the most essential features of these materials is the variation in properties as the orientation of the layer changes. This requires the use of advanced techniques for strength analysis, including numerical modelling and material testing. This paper presents an experimental evaluation approach to estimate the mechanical properties of composite shells, including cutting schemes, specimen preparation, and test procedures. In the next stage, this study discusses the use of ABAQUS FEA to replicate the phenomenon of specimen failure modes. The investigated prepreg specimens in this study were created using XC 130 unidirectional easy composite prepreg. Through this research, the failure mode results of testing and numerical analysis showed a good agreement. [ABSTRACT FROM AUTHOR]

In this paper the numerical investigations concerning static response of a different configurations of concrete columns subjected to Euler's load are presented. An original approach of connecting the column and pocket footing via steel cut-off pyramid heads is presented. As shown in other works the main difference between conventional planar ended column and the column ended with cut-off pyramid shape is the axial force redistribution at the connection. In the case of standard connection, the compressive force is transferred onto foundation and consequently from the point of connection that force is distributed outwardly with 45° degrees' incline angle onto the ground. With the presented cut-off pyramid connection, one makes possible to reduce foundation height as a result of transferring on footing and consequently to the ground only a part of the compressive force, whereas remaining amount of force is converted into tensile stress effectively taken over by steel reinforcement. A comparative numerical analysis using SolidWorks FEM based software between standard and proposed solution is performed taking into account columns' critical load and Misses-Hencky stress (MHS) redistribution near the columns' head. On the basis of presented results, both solutions advantages and disadvantages are emphasized. [ABSTRACT FROM AUTHOR]

The paper deals with the determination of the rotational stiffness of a timber semi-rigid joint. The rotational stiffness was calculated on the basis of the currently valid standard, experimental test and numerical model. The connection was made of a standard combination of bolts and dowels, which consisted of 10 pieces of fasteners with a diameter of 8 mm. The elements of the connection consisted of facades and two struts with a cross-section of 100x300 mm. The connection was then statically repeatedly loaded and relieved. The loading took place up to the level of the ultimate limit state and the unloading up to 10% of the maximum value. In order to determine the actual mechanical properties of timber and fasteners, partial tests were performed for the needs of numerical modelling. [ABSTRACT FROM AUTHOR]

Members of open double-symmetrical cross-sections are widely used in steel structures. In many cases their webs are subjected to transverse compression resulting from the effect of adjacent members or from the concentrated transverse loads. Resistance of the member web to transverse compression is affected by number of aspects, e.g. structural solution of the joint (welded or bolted with end plate), possible longitudinal normal stress in the member caused by axial load or bending moment, interaction with shear or effect of local buckling of the web. The paper focuses on specific problem of resistance of the web to transverse compression resulting from transverse load applied close to the unstiffened end of the member. The investigation of the resistance of the web to transverse compression is performed using advanced geometrically and materially nonlinear numerical analysis for various distances of the transverse load from the unstiffened end. The influence of this distance on transverse compression resistance is quantified. Rolled and welded cross-sections of various web slenderness are investigated. The results are, where possible, compared with results obtained from available design standards. [ABSTRACT FROM AUTHOR]

This paper deals with method of B-spline solution for a system of boundary value problems. The differential equations are useful in various fields of science and engineering. Some interesting real life problems involve more than one unknown function. These result in system of simultaneous differential equations. Such systems have been applied to many problems in mathematics, physics, engineering etc. In present paper, B-spline and B-spline with free parameter methods for the solution of a linear system of second-order boundary value problems are presented. The methods utilize the values of cubic B-spline and its derivatives at nodal points together with the equations of the given system and boundary conditions, ensuing into the linear matrix equation. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is examination of an application of modern parallel computing technique OpenMP to speed up the calculation in the numerical solution of parametric integral equations systems (PIES). The authors noticed, that solving more complex boundary problems by PIES sometimes requires large computing time. This paper presents the use of OpenMP and fast C++ linear algebra library Armadillo for boundary value problems modelled by 3D Laplace's equation and solved using PIES. The testing example shows that the use of mentioned technologies significantly increases speed of calculations in PIES. [ABSTRACT FROM AUTHOR]

The paper is devoted to investigation of mechanical response of an electro-viscoelastic structure (a structure with piezoelectric element attached to its surface) in case when electric voltage with prescribed parameters is applied to electrodes of piezoelectric element. A cantilever plate was considered as such a structure. An amplitude of displacements of the free end of the plate at resonant modes is considered as a mechanical response in case when forced steady-state vibrations occurring under kinematic or force loading are considered. Mechanical response of the structure is determined numerically using the ANSYS software package. Viscoelastic properties of a material of the plate are taken into account using the model with complex dynamic moduli. Within the frameworks of this paper relations between mechanical response of the structure and magnitude and polarity of electric voltage applied to electrodes of a piezoelectric element was obtained with respect to a type of excitation of vibrations. [ABSTRACT FROM AUTHOR]

Contact deformation behavior of elements of spherical support structures of different geometrical configuration was considered: with anti-friction layer located in the lower steel slab and with anti-friction layer applied to the spherical segment. Within the framework of the paper, numerical analysis of the effect of the anti-friction polymeric layer face angle of spherical support structures on the deformation behavior of the work as a whole and changes in the parameters of friction contact zones, in particular, was performed. On average, the maximum contact pressure level of the spherical support structure model with a layer located in the lower slab is 8.5 % lower, and the maximum level of normal-to-surface movements is more than 28% lower than that of the second model considered. The opening of the contact near the edge of the anti-friction layer approximately by 1% of the surface is observed in all considered variants of spherical support structures. Areas of contact detachment of the interface surfaces in the model with an anti-friction layer in the lower slab are observed at a face angle of 20 degrees or more. For the model with an anti-friction layer applied to the spherical segment, an opposite situation is observed, namely, the contact opening occurs at the face angles from 0 to 10 degrees. In general, with an increase in the face angle from 0 to 30 degrees, there is an increase in deformation parameters of the contact node and parameters of contact zones. [ABSTRACT FROM AUTHOR]

A simple finite volume scheme is proposed to solve the shallow water equations on staggered grids. We consider the one-dimensional nonlinear shallow water equations in their conservative forms. We limit our research results in this paper for subcritical flows. Numerical tests show that the scheme solves subcritical flow problems quite accurately. In addition, the computation is very cheap due to the simplicity of the scheme. [ABSTRACT FROM AUTHOR]

This paper presents numerical simulations of the water flow in the case of an emergency at the protective hydraulic engineering constructions. A mathematical model for simulation of flooding flow is based on Navier-Stokes equations coupled with the volume-of-fluid (VOF) method. The 2D computational domain is discretized via the finite volume method (FVM). For turbulence modelling, the k-ϵ model is chosen. The interface between air and liquid is captured by CICSAM (compressive interface capturing scheme for arbitrary meshes) scheme, whereas the semi-implicit method for pressure linked equations (SIMPLE) scheme is applied for the pressure-velocity coupling. A second order upwind discretization scheme is used for the momentum equations. The verification of the present results is produced on a single flooding water body. The results show a good agreement with previous simulations and experiments of different authors. Then the simulation is expanded and analysed for cases with two different types of obstacles. Numerical simulation results are illustrated by figures and tables. [ABSTRACT FROM AUTHOR]

This paper describes one method for a numerical solution of a Fredholm integral equation of the second kind. The kernel function has a special type of singularity called the diagonal one. The main result of this paper is the error estimation of the numerical solution based on the Nystr¨om method with singularity subtraction. The error estimate is compared to numerical examples. The error behavior and computing time of the Nytr¨om method is compared with alternative method. [ABSTRACT FROM AUTHOR]

Simulation of the aircraft assembly process is an important problem arising from the airline industry. To address this problem, a methodology was developed in previous studies, which is based on the contact problem solving. This paper is devoted to further development of numerical methods for simulation of fuselage junction riveting process. The methodology of a contact problem solving was developed to simulate the aircraft assembly process. In the developed algorithm, the initial contact problem is transformed into the problem of quadratic programming with linear constraints. As the installed fasteners restrict relative tangential displacements of assembled parts in the junction area, the relative tangential displacements are negligible in comparison with normal ones. This special feature of the problem justifies implementation of node-to-node contact model that is much simpler than general surface-to-surface model.However, this implementation imposes the restriction that all finite element nodes of parts in the contact area should coincide completely. This restriction creates difficulties during mesh building because it is much easier to build meshes of the parts independently from each other. The main contribution of this paper is introducing the method and extending the existing algorithm for airframe assembly simulation to the case of non-conformal meshes. This article introduces the method and the modernized algorithm for the riveting process with non-conformal meshes. [ABSTRACT FROM AUTHOR]