Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 5
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The structure of Austempered Ductile Iron (ADI) is depend of many factors at individual stages of casting production. There is a rich literature documenting research on the relationship between heat treatment and the resulting microstructure of cast alloy. A significant amount of research is conducted towards the use of IT tools for indications production parameters for thin-walled castings, allowing for the selection of selected process parameters in order to obtain the expected properties. At the same time, the selection of these parameters should make it possible to obtain as few defects as possible. The input parameters of the solver is chemical composition Determined by the previous system module. Target wall thickness and HB of the product determined by the user. The method used to implement the solver is the method of Particle Swarm Optimization (PSO). The developed IT tool was used to determine the parameters of heat treatment, which will ensure obtaining the expected value for hardness. In the first stage, the ADI cast iron heat treatment parameters proposed by the expert were used, in the next part of the experiment, the settings proposed by the system were used. Used of the proposed IT tool, it was possible to reduce the number of deficiencies by 3%. The use of the solver in the case of castings with a wall thickness of 25 mm and 41 mm allowed to indication of process parameters allowing to obtain minimum mechanical properties in accordance with the PN-EN 1564:2012 standard. The results obtained by the solver for the selected parameters were verified. The indicated parameters were used to conduct experimental research. The tests obtained as a result of the physical experiment are convergent with the data from the solver.
Go to article

Authors and Affiliations

K. Jaśkowiec
1 2
ORCID: ORCID
A. Opaliński
2
ORCID: ORCID
P. Kustra
2
D. Jach
3
D. Wilk-Kołodziejczyk
1 2
ORCID: ORCID

  1. Lukasiewicz Research Network-Krakow Institute of Technology, Poland
  2. AGH University of Science and Technology, Department of Applied Computer Science and Modelling, Poland
  3. Kutno Foundry, Poland
Download PDF Download RIS Download Bibtex

Abstract

In the two-sided mixed-model assembly line, there is a process of installing two single stations

in each position left and right of the assembly line with the combining of the product model.

The main aim of this paper is to develop a new mathematical model for the mixed model

two-sided assembly line balancing (MTALB) generally occurs in plants producing large-sized

high-volume products such as buses or trucks.

According to the literature review, authors focus on research gap that indicate in MTALB

problem, minimize the length of the line play crucial role in industry space optimization.In

this paper, the proposed mathematical model is applied to solve benchmark problems of

two-sided mixed-model assembly line balancing problem to maximize the workload on each

workstation which tends to increase the compactness in the beginning workstations which

also helps to minimize the length of the line.

Since the problem is well known as np-hard problem benchmark problem is solved using

a branch and bound algorithm on lingo 17.0 solver and based on the computational results,

station line effectiveness and efficiency that is obtained by reducing the length of the line in

mated stations of the assembly line is increased.

Go to article

Authors and Affiliations

Ashish Yadav
Pawan Verma
Sunil Agrawal
Download PDF Download RIS Download Bibtex

Abstract

The article discusses an example of the use of graph search algorithms with trace of water analysis and aggregation of failures in the occurrence of a large number of failures in the Water Supply System (WSS). In the event of a catastrophic situation, based on the Water Distribution System (WDS) network model, information about detected failures, the condition and location of valves, the number of repair teams, criticality analysis, the coefficient of prioritization of individual network elements, and selected objective function, the algorithm proposes the order of repairing the failures should be analyzed. The approach proposed by the authors of the article assumes the selection of the following objective function: minimizing the time of lack of access to drinking water (with or without prioritization) and minimizing failure repair time (with or without failure aggregation). The algorithm was tested on three different water networks (small, medium, and large numbers of nodes) and three different scenarios (different numbers of failures and valves in the water network) for each selected water network. The results were compared to a valve designation approach for closure using an adjacency matrix and a Strategic Valve Management Model (SVMM).
Go to article

Authors and Affiliations

Ariel Antonowicz
1
ORCID: ORCID
Andrzej Urbaniak
1

  1. Institute of Computing Science, Poznan University of Technology, ul. Piotrowo 2, 60-965 Poznan, Poland
Download PDF Download RIS Download Bibtex

Abstract

In times of the COVID-19, reliable tools to simulate the airborne pathogens causing the infection are extremely important to enable the testing of various preventive methods. Advection-diffusion simulations can model the propagation of pathogens in the air. We can represent the concentration of pathogens in the air by “contamination” propagating from the source, by the mechanisms of advection (representing air movement) and diffusion (representing the spontaneous propagation of pathogen particles in the air). The three-dimensional time-dependent advection-diffusion equation is difficult to simulate due to the high computational cost and instabilities of the numerical methods. In this paper, we present alternating directions implicit isogeometric analysis simulations of the three-dimensional advection-diffusion equations. We introduce three intermediate time steps, where in the differential operator, we separate the derivatives concerning particular spatial directions. We provide a mathematical analysis of the numerical stability of the method. We show well-posedness of each time step formulation, under the assumption of a particular time step size. We utilize the tensor products of one-dimensional B-spline basis functions over the three-dimensional cube shape domain for the spatial discretization. The alternating direction solver is implemented in C++ and parallelized using the GALOIS framework for multi-core processors. We run the simulations within 120 minutes on a laptop equipped with i7 6700 Q processor 2.6 GHz (8 cores with HT) and 16 GB of RAM.
Go to article

Bibliography

  1.  “Coronavirus disease (COVID-19): How is it transmitted?”. [Online] Available: https://www.who.int/emergencies/diseases/novel- coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-how-is-covid-19-transmitted.
  2.  D.W. Peaceman and H.H. Rachford Jr., “The numerical solution of parabolic and elliptic differential equations’’, J. Soc. Ind. Appl. Math., vol. 3, no. 1, pp. 28‒41, 1955.
  3.  J. Douglasand and H. Rachford, “On the numerical solution of heat conduction problems in two and three space variables’’, Trans. Am. Math. Soc., vol. 82, no. 2, pp. 421‒439, 1956.
  4.  E.L. Wachspress and G. Habetler, “An alternating-direction-implicit iteration technique’’, J. Soc. Ind. Appl. Math., vol. 8, no. 2, pp. 403‒423, 1960.
  5.  G. Birkhoff, R.S. Varga, and D. Young, “Alternating direction implicit methods’’, Adv. Comput., vol. 3, pp. 189‒273, 1962.
  6.  J.L. Guermond and P. Minev, “A new class of fractional step techniques for the incompressible Navier-Stokes equations using direction splitting’’, C.R. Math., vol. 348, pp. 581‒585, 2010.
  7.  J.L. Guermond, P. Minev, and J. Shen, “An overview of projection methods for incompressible flows’’, Comput. Methods Appl. Mech. Eng., vol. 195, pp. 6011‒6054, 2006.
  8.  J.A. Cottrell, T. J. R. Hughes, and Y. Bazilevs, Isogeometric Analysis: Toward Unification of CAD and FEA, John Wiley and Sons, 2009.
  9.  M.-C. Hsu, I. Akkerman, and Y. Bazilevs, “High-performance computing of wind turbine aerodynamics using isogeometric analysis’’, Comput. Fluids, vol. 49, pp. 93‒100, 2011.
  10.  K. Chang, T.J.R. Hughes, and V.M. Calo, “Isogeometric variational multiscale large-eddy simulation of fully-developed turbulent flow over a wavy wall’’, Comput. Fluids, vol. 68, pp. 94‒104, 2012.
  11.  L. Dedè, T.J.R. Hughes, S. Lipton, and V.M. Calo, “Structural topology optimization with isogeometric analysis in a phase field approach’’, USNCTAM2010, 16th US National Congree of Theoretical and Applied Mechanics, 2010.
  12.  L. Dedè, M.J. Borden, and T.J.R. Hughes, “Isogeometric analysis for topology optimization with a phase field model’’, Arch. Comput. Methods Eng., vol. 19, pp. 427‒465, 2012.
  13.  H. Gómez, V.M. Calo, Y. Bazilevs, and T.J.R. Hughes, “Isogeometric analysis of the {Cahn-Hilliard} phase-field model’’, Comput. Methods Appl. Mech. Eng., vol. 197, pp. 4333‒4352, 2008.
  14.  H. Gómez, T.J.R. Hughes, X. Nogueira, and V.M. Calo, “Isogeometric analysis of the isothermal Navier-Stokes-Korteweg equations’’, Comput. Methods Appl. Mech. Eng., vol. 199, pp. 1828‒1840, 2010.
  15.  R. Duddu, L. Lavier, T.J.R. Hughes, and V.M. Calo, “A finite strain Eulerian formulation for compressible and nearly incompressible hyper-elasticity using high-order NURBS elements’’, Int. J. Numer. Methods Eng., vol. 89, pp. 762‒785, 2012.
  16.  S. Hossain, S.F.A. Hossainy, Y. Bazilevs, V.M. Calo, and T.J.R. Hughes, “Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls’’, Comput. Mech., vol. 49, pp. 213‒242, 2012.
  17.  Y. Bazilevs, V.M. Calo, Y. Zhang, and T.J.R. Hughes, “Isogeometric fluid-structure interaction analysis with applications to arterial blood flow’’, Comput. Mech., vol. 38, pp. 310‒322, 2006.
  18.  Y. Bazilevs, V.M. Calo, J.A. Cottrell, T.J.R. Hughes, A. Reali, and G. Scovazzi, “Variational multiscale residual-based turbulence modeling for large eddy simulation of incompressible flows’’, Comput. Methods Appl. Mech. Eng., vol. 197, pp. 173‒201, 2007.
  19.  V.M. Calo, N. Brasher, Y. Bazilevs, and T.J.R. Hughes, “Multiphysics Model for Blood Flow and Drug Transport with Application to Patient-Specific Coronary Artery Flow’’, Comput. Mech., vol. 43, pp. 161‒177, 2008.
  20.  M. Łoś, M. Paszyński, A. Kłusek, and W. Dzwinel, “Application of fast isogeometric L2 projection solver for tumor growth simulations’’, Comput. Methods Appl. Mech. Eng., vol. 316, pp. 1257‒1269, 2017.
  21.  M. Łoś, A. Kłusek, M. Amber Hassam, K. Pingali, W. Dzwinel, and M. Paszyński, “Parallel fast isogeometric L2 projection solver with GALOIS system for 3D tumor growth simulations’’, Comput. Methods Appl. Mech. Eng., vol. 343, pp. 1‒22, 2019.
  22.  A. Paszyńska, K. Jopek. M. Woźniak, and M. Paszyński, “Heuristic algorithm to predict the location of C0 separators for efficient isogeometric analysis simulations with direct solvers’’, Bull. Pol. Acad. Sci. Tech. Sci., vol. 66, no. 6, pp. 907‒917, 2018.
  23.  L. Gao and V.M. Calo, “Fast Isogeometric Solvers for Explicit Dynamics’’, Comput. Methods Appl. Mech. Eng., vol. 274, pp. 19‒41, 2014.
  24.  L. Gao and V.M. Calo, “Preconditioners based on the alternating-direction-implicit algorithm for the 2D steady-state diffusion equation with orthotropic heterogeneous coefficients’’, J. Comput. Appl. Math., vol. 273, pp. 274‒295, 2015.
  25.  L. Gao, “Kronecker Products on Preconditioning’’, PhD. Thesis, King Abdullah University of Science and Technology, 2013.
  26.  M. Łoś, M. Woźniak, M. Paszyński, L. Dalcin, and V.M. Calo, “Dynamics with Matrices Possessing Kronecker Product Structure’’, Procedia Comput. Sci., vol. 51, pp. 286‒295, 2015.
  27.  M. Woźniak, M. Łoś, M. Paszyński, L. Dalcin, and V. Calo, “Parallel fast isogeometric solvers for explicit dynamics’’, Comput. Inform., vol. 36, no. 2, pp. 423‒448, 2017.
  28.  M. Łoś, M. Woźniak, M. Paszyński, A. Lenharth, and K. Pingali, “IGA-ADS : Isogeometric Analysis FEM using ADS solver’’, Comput. Phys. Commun., vol. 217, pp. 99‒116, 2017.
  29.  G. Gurgul, M. Woźniak, M. Łoś, D. Szeliga, and M. Paszyński, “Open source JAVA implementation of the parallel multi-thread alternating direction isogeometric L2 projections solver for material science simulations’’ Comput. Methods Mater. Sci., vol. 17, no.1, pp. 1‒11, 2017.
  30.  M. Łoś, J. Munoz-Matute, K. Podsiadło, M. Paszyński, and K. Pingali, “Parallel shared-memory isogeometric residual minimization (iGRM) for three-dimensional advection-diffusion problems’’, Lect. Notes Comput. Sci., vol. 12143, pp. 133‒148, 2020.
  31.  A. Alonso, R. Loredana Trotta, and A. Valli, “Coercive domain decomposition algorithms for advection-diffusion equations and systems’’, J. Comput. Appl. Math., vol. 96, no. 1, pp. 51‒76, 1998.
  32.  K. Pingali, D. Nguyen, M. Kulkarni, M. Burtscher, M.A. Hassaan, R. Kaleem, T.-H. Lee, A. Lenharth, R. Manevich, M. Mendez-Lojo, D. Prountzos, and X. Sui, “The tao of parallelism in algorithms’’, SIGPLAN, vol. 46, 2011, doi: 10.1145/1993316. 1993501.
  33.  A. Takhirov, R. Frolov, and P. Minev, “Direction splitting scheme for Navier-Stokes-Boussinesq system in spherical shell geometries’’, arXiv:1905.02300, 2019.
Go to article

Authors and Affiliations

Marcin Łoś
1
ORCID: ORCID
Maciej Woźniak
1
ORCID: ORCID
Ignacio Muga
2
ORCID: ORCID
Maciej Paszynski
1
ORCID: ORCID

  1. AGH University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, al. Mickiewicza 30, 30-059 Krakow, Poland
  2. Instituto de Matemáticas, Pontificia Universidad Católica de Valparaíso, Chile

This page uses 'cookies'. Learn more