Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 12
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Evaluation of moisture absorption in foodstuffs such as black chickpea is an important stage for skinning and cropping practices. Water uptake process of black chickpea was discussed through normal soaking in four temperature levels of 20, 35, 50 and 65 °C for 18 hours, and then the hydration kinetics was predicted by Peleg’s model and finite difference strategy. Model results showed that with increasing soaking temperature from 20 to 65 °C, Peleg’s rate and Peleg’s capacity constant reduced from 13.368×10-2 to 5.664×10-2 and 9.231×10-3 to 9.138×10-3, respectively. Based on key results, a rise in the medium temperature caused an increase in the diffusion coefficient from 5.24×10-10 m2/s to 4.36×10-9 m2/s, as well. Modelling of moisture absorption of black chickpea was also performed employing finite difference strategy. Comparing the experimental results with those obtained from the analytical solution of the theoretical models revealed a good agreement between predicted and experimental data. Peleg’s model and finite difference technique revealed their predictive function the best at the temperature of 65 °C.

Go to article

Authors and Affiliations

Nesa Dibagar
Stefan Jan Kowalski
Reza Amiri Chayjan
Download PDF Download RIS Download Bibtex

Abstract

The main aim of this analysis is to consider a mutual interference between aircraft motion and surrounding flow field. Euler flow model for inviscid, compressible gas and aircraft flight dynamics model was used to analyse quick dynamic manoeuvres. For such manoeuvres, aerodynamic hysteresis has a great influence on aircraft dynamics, which cannot be simulated with the assumption of quasi-steady aerodynamics. On the other hand, the aircraft motion as a rigid body strongly influences the flow field around itself. To account for this mutual interference, the Euler flow equations were used to obtain aerodynamic forces and moments acting on a simplified aircraft configuration (main wing+ tailplane only) during pull-out manoeuvre, and the flight dynamics equations of motion were used to describe dynamics of an aircraft. Initial conditions for the flight dynamics equation of motion were settled up coming from the solution of the Euler flow model. As a test case, a weak pull-out manoeuvre was selected. During this manoeuvre, the highest value of angle of attack doesn't exceed 12 degrees - the value which can be obtained from the classical approach based on flight dynamics equations of motion with quasisteady aerodynamics. However, coupled Euler flight dynamic model has much wider applicability, and can be used for the analysis of manoeuvres at high angles of attack, including large scale separation at sharp edges, unsteadiness and flow asymmetries even for symmetrical undisturbed flowficld case. This method, if successfully verified to a number of important flight manoeuvres (such as spin, Cobra manoeuvre, roll at high angles of attack and other) can open a new, very promising field in the analysis of aircraft dynamics.
Go to article

Authors and Affiliations

Tomasz Iglewski
Zdobysław Goraj
Download PDF Download RIS Download Bibtex

Abstract

This paper compares numerical solutions of transient two-dimensional unsaturated flow equation by using different averaging schemes for internodal conductivities. Averaging methods such as arithmetic mean, geometric mean, upstream weighting, and integrated mean are taken into account, as well as a recent approach based on steady-state approximation. The latter method proved the most flexible, producing relatively accurate solutions for both downward and upward flow cases.

Go to article

Authors and Affiliations

A. Szymkiewicz
K. Burzyński
Download PDF Download RIS Download Bibtex

Abstract

The paper presents the dynamic behaviour of three-layer annular plates with damaged facings. The plate is composed of thin laminated, fibre-reinforced composite facings and thicker, foam core. Failure of the plate facings is modelled as fibre or matrix cracks. The plate loaded in the plane of facings with quickly increasing radially compressed forces loses its dynamic stability. Evaluation of the critical state of the plate with failures was carried out using both analytical and numerical solutions. The comparison of results between plates with material properties treated as isotropic, quasi-isotropic and composite has been conducted. Presented tables and figures create the image of dynamic responses of examined composite plates with structure failures.

Go to article

Authors and Affiliations

Dorota Pawlus
Download PDF Download RIS Download Bibtex

Abstract

The deformation modulus of the rock mass as a very important parameter in rock mechanic projects generally is determined by the plate load in-situ tests. While this test is very expensive and time-consuming, so in this study a new method is developed to combin artificial neural networks and numerical modeling for predicting deformation modulus of rock masses. For this aim, firstly, the plate load test was simulated using a Finite Difference numerical model that was verified with actual results of the plate load test in Pirtaghi dam galleries in Iran. Secondly, an artificial neural network is trained with a set of data resulted from numerical simulations to estimate the deformation modulus of the rock mass. The results showed that an ANN with five neurons in the input layer, three hidden layers with 4, 3 and 2 neurons, and one neuron in the output layer had the best accuracy for predicting the deformation modulus of the rock mass.

Go to article

Authors and Affiliations

Narges Saadat Tayarani
Saeed Jamali
Mehdi Motevalli Zadeh
Download PDF Download RIS Download Bibtex

Abstract

The Laplace operator is a differential operator which is used to detect edges of objects in digital images. This paper presents the properties of the most commonly used third-order 3x3 pixels Laplace contour filters including the difference schemes used to derive them. The authors focused on the mathematical properties of the Laplace filters. The basic reasons of the differences of the properties were studied and indicated using their transfer functions and modified differential equations. The relations between the transfer function for the differential Laplace operator and its difference operators were described and presented graphically. The impact of the corner elements of the masks on the results was discussed. This is a theoretical work. The basic research conducted here refers to a few practical examples which are illustrations of the derived conclusions.We are aware that unambiguous and even categorical final statements as well as indication of areas of the results application always require numerous experiments and frequent dissemination of the results. Therefore, we present only a concise procedure of determination of the mathematical properties of the Laplace contour filters matrices. In the next paper we shall present the spectral characteristic of the fifth order filters of the Laplace type.
Go to article

Authors and Affiliations

Ireneusz Winnicki
1
ORCID: ORCID
Janusz Jasinski
1
ORCID: ORCID
Slawomir Pietrek
1
ORCID: ORCID
Krzysztof Kroszczynski
1
ORCID: ORCID

  1. Military University of Technology, Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

In the paper, the numerical method of solving the one-dimensional subdiffusion equation with the source term is presented. In the approach used, the key role is played by transforming of the partial differential equation into an equivalent integro-differential equation. As a result of the discretization of the integro-differential equation obtained an implicit numerical scheme which is the generalized Crank-Nicolson method. The implicit numerical schemes based on the finite difference method, such as the Carnk-Nicolson method or the Laasonen method, as a rule are unconditionally stable, which is their undoubted advantage. The discretization of the integro-differential equation is performed in two stages. First, the left-sided Riemann-Liouville integrals are approximated in such a way that the integrands are linear functions between successive grid nodes with respect to the time variable. This allows us to find the discrete values of the integral kernel of the left-sided Riemann-Liouville integral and assign them to the appropriate nodes. In the second step, second order derivative with respect to the spatial variable is approximated by the difference quotient. The obtained numerical scheme is verified on three examples for which closed analytical solutions are known.
Go to article

Bibliography

  1.  T. Kosztołowicz, K. Dworecki, and S. Mrówczyński, “How to measure subdiffusion parameters,” Phys. Rev. Lett., vol. 94, p.  170602, 2005, doi: 10.1016/j.tins.2004.10.007.
  2.  T. Kosztołowicz, K. Dworecki, and S. Mrówczyński, “Measuring subdiffusion parameters,” Phys. Rev. E, vol. 71, p.  041105, 2005.
  3.  E. Weeks, J. Urbach, and L. Swinney, “Anomalous diffusion in asymmetric random walks with a quasi-geostrophic flow example,” Physica D, vol. 97, pp. 291–310, 1996.
  4.  T. Solomon, E. Weeks, and H. Swinney, “Observations of anomalous diffusion and Lévy flights in a 2-dimensional rotating flow,” Phys. Rev. Lett., vol. 71, pp. 3975–3979, 1993.
  5.  N.E. Humphries, et al., “Environmental context explains Lévy and Brownian movement patterns of marine predators,” Nature, vol. 465, pp. 1066–1069, 2010.
  6.  U. Siedlecka, “Heat conduction in a finite medium using the fractional single-phase-lag model,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 67, pp. 402–407, 2019.
  7.  R. Metzler and J. Klafter, “The random walk:s guide to anomalous diffusion: a fractional dynamics approach,” Phys. Rep., vol. 339, pp. 1–77, 2000.
  8.  R. Metzler and J. Klafter, “The restaurant at the end of the random walk: recent developments in the description of anomalous transport by fractional dynamics,” J. Phys. A: Math. Gen., vol. 37, pp. 161–208, 2004.
  9.  M. Aslefallah, S. Abbasbandy, and E. Shivanian, “Numerical solution of a modified anomalous diffusion equation with nonlinear source term through meshless singular boundary method,” Eng. Anal. Boundary Elem., vol. 107, pp. 198–207, 2019.
  10.  Y. Li and D. Wang, “Improved efficient difference method for the modified anomalous sub-diffusion equation with a nonlinear source term,” Int. J. Comput. Math., vol. 94, pp. 821–840, 2017.
  11.  X. Cao, X. Cao, and L. Wen, “The implicit midpoint method for the modified anomalous sub-diffusion equation with a nonlinear source term,” J. Comput. Appl. Math., vol. 318, pp. 199–210, 2017.
  12.  A. Kilbas, H. Srivastava, and J. Trujillo, Theory and Applications of Fractional Differential Equations. Amsterdam: Elsevier, 2006.
  13.  E.D. Rainville, Special Functions. New York: The Macmillan Company, 1960.
  14.  J.-L. Liu and H.MSrivastava, “Classes of meromorphically multivalent functions associated with the generalized hypergeometric function,” Math. Comput. Modell., vol. 39, pp. 21–34, 2004.
  15.  Y.L. Luke, “Inequalities for generalized hypergeometric functions,” J. Approximation Theory, vol. 5, pp. 41–65, 1972.
  16.  M. Włodarczyk and A. Zawadzki, “The application of hypergeometric functions to computing fractional order derivatives of sinusoidal functions,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 64, pp. 243–248, 2016.
  17.  M. Błasik, “A generalized Crank-Nicolson method for the solution of the subdiffusion equation,” 23rd International Conference on Methods & Models in Automation & Robotics (MMAR), pp.  726–729, 2018.
  18.  M. Błasik, “Zagadnienie stefana niecałkowitego rzędu,” Ph.D. dissertation, Politechnika Częstochowska, 2013.
  19.  M. Błasik and M. Klimek, “Numerical solution of the one phase 1d fractional stefan problem using the front fixing method,” Math. Methods Appl. Sci., vol. 38, no. 15, pp. 3214–3228, 2015.
  20.  K. Diethelm, The Analysis of Fractional Differential Equations. Berlin: Springer-Verlag, 2010.
Go to article

Authors and Affiliations

Marek Błasik
1

  1. Institute of Mathematics, Czestochowa University of Technology, al. Armii Krajowej 21, 42-201 Czestochowa, Poland
Download PDF Download RIS Download Bibtex

Abstract

The problem of the arch barrel deformation in railway backfilled arch bridges caused by their typical service loads is analysed. The main attention is paid to vertical or radial displacements of characteristic points of the arch barrel. In the study results of deflection measurements carried out on single and multi-span backfilled arch bridges made of bricks or plain concrete during passages of various typical railway vehicles are used. On the basis of such results empirical influence functions of displacements are being created. In the next step, the results are utilised to estimate bending effects within the arch. The paper includes different procedures based on measurements of displacements in various points and directions. Using empirical influence functions arbitrary virtual load cases may be also considered. In this manner the proposed methodology shows a potential to be an effective tool of comprehensive calibration of numerical models of backfilled arch bridges on the basic of field tests carried out under any live loads.
Go to article

Authors and Affiliations

Tomasz Kamiński
1
ORCID: ORCID
Czesław Machelski
1
ORCID: ORCID

  1. Wroclaw University of Science and Technology, Faculty of Civil Engineering, Wyb. Wyspianskiego 27, 50-370 Wrocław, Poland
Download PDF Download RIS Download Bibtex

Abstract

The problem of optimal design of symmetrical double-lap adhesive joint is considered. It is assumed that the main plate has constant thickness, while the thickness of the doublers can vary along the joint length. The optimization problem consists in finding optimal length of the joint and an optimal cross-section of the doublers, which provide minimum structural mass at given strength constraints. The classical Goland-Reissner model was used to describe the joint stress state. A corresponding system of differential equations with variable coefficients was solved using the finite difference method. Genetic optimization algorithm was used for numerical solution of the optimization problem. In this case, Fourier series were used to describe doubler thickness variation along the joint length. This solution ensures smoothness of the desired function. Two model problems were solved. It is shown that the length and optimal shape of the doubler depend on the design load.
Go to article

Bibliography

[1] L.F.M. da Silva, P.J.C. das Neves, R.D. Adams, and J.K. Spelt. Analytical models of adhesively bonded joints. Part I: Literature survey. International Journal of Adhesion and Adhesives, 29(3):319–330, 2009. doi: 10.1016/j.ijadhadh.2008.06.005.
[2] E.H. Wong and J. Liu. Interface and interconnection stresses in electronic assemblies – A critical review of analytical solutions. Microelectronics Reliability, 79:206–220, 2017. doi: 10.1016/j.microrel.2017.03.010.
[3] S. Budhe, M.D. Banea, S. de Barros, and L.F.M. da Silva. An updated review of adhesively bonded joints in composite materials. International Journal of Adhesion and Adhesives, 72:30–42, 2017. doi: 10.1016/j.ijadhadh.2016.10.010.
[4] K.P. Barakhov and I.M. Taranenko. Influence of joint edge shape on stress distribution in adhesive film. In: M. Nechyporuk, V. Pavlikov, D. Kritskiy (eds) Integrated Computer Technologies in Mechanical Engineering – 2021. ICTM 2021. Lecture Notes in Networks and Systems, 367:123–132, Springer, Cham, 2022. doi: 10.1007/978-3-030-94259-5_12.
[5] H. Lee, S. Seon, S. Park, R. Walallawita, and K. Lee. Effect of the geometric shapes of repair patches on bonding strength. The Journal of Adhesion, 97(3):1–18, 2019. doi: 10.1080/00218464.2019.1649660.
[6] F. Ramezani, M.R. Ayatollahi, A. Akhavan-Safar, and L.F.M. da Silva. A comprehensive experimental study on bi-adhesive single lap joints using DIC technique. International Journal of Adhesion and Adhesives, 102:102674, 2020. doi: 10.1016/j.ijadhadh.2020.102674.
[7] Ya.S. Karpov. Jointing of high-loaded composite structural components. Part 2. Modeling of stress-strain state. Strength of Materials, 38(5):481–491, 2006. doi: 10.1007/s11223-006-0067-9.
[8] J. Kupski and S. Teixeira de Freitas. Design of adhesively bonded lap joints with laminated CFRP adherends: Review, challenges and new opportunities for aerospace structures. Composite Structures, 268:113923, 2021. doi: 10.1016/j.compstruct.2021.113923.
[9] S. Amidi and J. Wang. An analytical model for interfacial stresses in double-lap bonded joints. The Journal of Adhesion, 95(11):1031–1055, 2018. doi: 10.1080/00218464.2018.1464917.
[10] H. Kumazawa and T. Kasahara. Analytical investigation of thermal and mechanical load effects on stress distribution in adhesive layer of double-lap metal-composite bonded joints. Advanced Composite Materials, 28(4):425–444, 2019. doi: 10.1080/09243046.2019.1575028.
[11] S. Kurennov and N. Smetankina. Stress-strain state of a double lap joint of circular form. Axisymmetric model. In: M. Nechyporuk, V. Pavlikov D. Kritskiy (eds) Integrated Computer Technologies in Mechanical Engineering – 2021. ICTM 2021. Lecture Notes in Networks and Systems, 367:36–46, Springer, Cham, 2022. doi: 10.1007/978-3-030-94259-5_4.
[12] S. E. Stapleton, B. Stier, S. Jones, A. Bergan, I. Kaleel, M. Petrolo, E. Carrera, and B.A. Bednarcyk. A critical assessment of design tools for stress analysis of adhesively bonded double lap joints. Mechanics of Advanced Materials and Structures, 28(8):791–811, 2019. doi: 10.1080/15376494.2019.1600768.
[13] R.H. Kaye and M. Heller. Through-thickness shape optimisation of bonded repairs and lap-joints. I nternational Journal of Adhesion and Adhesives, 22(1):7–21, 2002. doi: 10.1016/s0143-7496(01)00029-x.
[14] S. Kurennov, K. Barakhov, I. Taranenko, and V. Stepanenko. A genetic algorithm of optimal design of beam at restricted sagging. Radioelectronic and Computer Systems, 1:83–91, 2022. doi: 10.32620/reks.2022.1.06.
[15] V.S. Symonov, I.S. Karpov, and J. Juračka. Optimization of a panelled smooth composite shell with a closed cross-sectional contour by using a genetic algorithm. Mechanics of Composite Materials, 49(5):563–570, 2013. doi: 10.1007/s11029-013-9372-0.
[16] N.S. Kulkarni, V.K. Tripathi. Variable thickness approach for finding minimum laminate thickness and investigating effect of different design variables on its performance. Archive of Mechanical Engineering, 65(4):527–551, 2018. doi: 10.24425/ame.2018.125441.
[17] H. Ejaz, A. Mubashar, I.A. Ashcroft, E. Uddin, and M. Khan. Topology optimisation of adhesive joints using non-parametric methods. International Journal of Adhesion and Adhesives, 81:1–10, 2018. doi: 10.1016/j.ijadhadh.2017.11.003.
[18] H.L. Groth and P. Nordlund. Shape optimization of bonded joints. International Journal of Adhesion and Adhesives, 11(4):204–212, 1991. doi: 10.1016/0143-7496(91)90002-y.
[19] R.Q. Rodríguez, R. Picelli, P. Sollero, and R. Pavanello. Structural shape optimization of bonded joints using the ESO method and a honeycomb-like mesh. J ournal of Adhesion Science and Technology, 28(14-15):1451–1466, 2014. doi: 10.1080/01694243.2012.698112.
[20] E.G. Arhore, M. Yasaee, and I. Dayyani. Comparison of GA and topology optimization of adherend for adhesively bonded metal composite joints. International Journal of Solids and Structures, 226-227:111078, 2021. doi: 10.1016/j.ijsolstr.2021.111078.
[21] S. Kumar, and de A. de Tejada Alvarez. Modeling of geometrically graded multi-material single-lap joints. 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. doi: 10.2514/6.2015-1885.
[22] S.S. Kurennov: Refined mathematical model of the stress state of adhesive lap joint: experimental determination of the adhesive layer strength criterion. Strength of Materials, 52:779–789, 2020. doi: 10.1007/s11223-020-00231-5.
[23] P. Zou, J. Bricker, and W. Uijttewaal. Optimization of submerged floating tunnel cross section based on parametric Bézier curves and hybrid backpropagation – genetic algorithm. Marine Structures, 74:102807, 2020. doi: 10.1016/j.marstruc.2020.102807.
[24] O. Coskun and H.S.Turkmen. Multi-objective optimization of variable stiffness laminated plates modeled using Bézier curves. Composite Structures, 279:114814, 2022. doi: 10.1016/j.compstruct.2021.114814.
[25] S. Kumar and P.C. Pandey. Behaviour of bi-adhesive joints. Journal of Adhesion Science and Technology, 24(7):1251–1281, 2010. doi: 10.1163/016942409x12561252291982.
[26] Ö. Öz and H. Özer. On the von Mises elastic stress evaluations in the bi-adhesive single-lap joint: a numerical and analytical study. Journal of Adhesion Science and Technology, 28(21):2133–2153, 2014. doi: 10.1080/01694243.2014.948110.
[27] E. Selahi. Elasticity solution of adhesive tubular joints in laminated composites with axial symmetry. Archive of Mechanical Engineering, 65(3):441–456, 2018. doi: 10.24425/124491.
[28] K. Barakhov, D. Dvoretska, and O. Poliakov. One-dimensional axisymmetric model of the stress state of the adhesive joint. In: M. Nechyporuk, V. Pavlikov, D. Kritskiy (eds) I ntegrated Computer Technologies in Mechanical Engineering – 2020. ICTM 2020. Lecture Notes in Networks and Systems, 188:310–319, Springer, Cham, 2021. doi: 10.1007/978-3-030-66717-7_26.
[29] S. Kurennov, N. Smetankina, V. Pavlikov, D. Dvoretskaya, V. Radchenko. Mathematical model of the stress state of the antenna radome joint with the load-bearing edging of the skin cutout. In: D.D. Cioboată, (ed.) International Conference on Reliable Systems Engineering (ICoRSE) – 2021. ICoRSE 2021. Lecture Notes in Networks and Systems, 305:287–295, Springer, Cham, 2022. doi: 10.1007/978-3-030-83368-8_28.
Go to article

Authors and Affiliations

Sergei Kurennov
1
ORCID: ORCID
Konstantin Barakhov
1
ORCID: ORCID
Olexander Polyakov
1
ORCID: ORCID
Igor Taranenko
1
ORCID: ORCID

  1. National Aerospace University “Kharkiv Aviation Institute”, Kharkiv, Ukraine
Download PDF Download RIS Download Bibtex

Abstract

Thin metal film subjected to a short-pulse laser heating is considered. The parabolic two-temperature model describing the temporal and spatial evolution of the lattice and electrons temperatures is discussed and the melting process of thin layer is taken into account. At the stage of numerical computations the finite difference method is used. In the final part of the paper the examples of computations are shown.

Go to article

Authors and Affiliations

E. Majchrzak
J. Dziatkiewicz
Download PDF Download RIS Download Bibtex

Abstract

Three-layered, annular plate with viscoelastic core is subjected to loads acting in the plane of the plate facings. One formulates the dynamic, stability problem concerning the action of time-dependent compressive stress on a plate with imperfection. This problem has been solved. One created the basic system of differential equations in which the approximation finite difference method was used for calculations. The essential analysis of the problem was concentrated on evaluation of the influence of the plate imperfection rate and the rate of plate loading growth on the results of calculation of critical parameters at the moment of loss of plate stability. It determines the analysed problem of sensitivity of the plate to imperfection and loading. In the evaluation of the dynamics of this problem, the dynamic factor defined as the quotient of the critical, dynamic load to the static one was used. The idea of dynamic factor and the type of the accepted criterion of the loss of plate stability were taken from the Volmir's work. The observations were confirmed by comparable results of calculations of plate models built in finite element method using the ABAQUS system. The analysis of the stress state in an exemplary plate model calculated in FEM demonstrated the importance of the strength condition in total evaluation of the plate work. One achieved satisfactory correctness of results in both methods.

Go to article

Authors and Affiliations

Dorota Pawlus
Download PDF Download RIS Download Bibtex

Abstract

The Laplace operator is a differential operator which is used to detect edges of objects in digital images. This paper presents the properties of the most commonly used fifth-order pixels Laplace filters including the difference schemes used to derive them (finite difference method – FDM and finite element method – FEM). The results of the research concerning third-order pixels matrices of the convolution Laplace filters used for digital processing of images were presented in our previous paper: The mathematical characteristic of the Laplace contour filters used in digital image processing. The third order filters is presented byWinnicki et al. (2022). As previously, the authors focused on the mathematical properties of the Laplace filters: their transfer functions and modified differential equations (MDE). The relations between the transfer function for the differential Laplace operator and its difference operators are described and presented here in graphical form. The impact of the corner elements of the masks on the results is also discussed. A transfer function, is a function characterizing properties of the difference schemes applied to approximate differential operators. Since they are relations derived in both types of spaces (continuous and discrete), comparing them facilitates the assessment of the applied approximation method.
Go to article

Authors and Affiliations

Ireneusz Winnicki
1
ORCID: ORCID
Slawomir Pietrek
1
ORCID: ORCID
Janusz Jasinski
1
ORCID: ORCID
Krzysztof Kroszczynski
1
ORCID: ORCID

  1. Military University of Technology, Warsaw, Poland

This page uses 'cookies'. Learn more