Volume 17, Issue 2, August 2015, Pages 370–380
C. Christopher Senfuka1, Paul Kizito2, J.B. John Kirabira3, and J.K. Joseph Byaruhanga4
1 Dept. of Mechanical & Production Engineering, Kyambogo University, Kampala, Uganda
2 Dept. of Mechanical & Production Engineering, Kyambogo University, Kampala, Uganda
3 Dept. of Mechanical Engineering, Makerere University, Kampala, Uganda
4 Dept. of Mechanical Engineering, Makerere University, Kampala, Uganda
Original language: English
Copyright © 2015 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Deciding the functional suitability of recycled steel using carbon equivalent (CE) and strength can be misleading since the formulae used to determine CE do not capture many of the elements that play a decisive role in establishing steel values. In this study, a mathematical model is developed to optimize the selection decision from a steel manufacturer considering a stochastic CE distribution. In the given model, a building/fabrication contractor intends to select one of two manufacturers of recycled steel bars basing on CE as determined by the IIW formula and strength values selected in equal monthly intervals. A Markov decision process approach is adopted where three states of a Markov chain represent possible states of CE of steel bars. The ultimate strength, σu, of steel is maximized for minimum CE where the decision to select the best steel is made using dynamic programming over a finite period planning horizon. A numerical example demonstrates the existence of an optimal state-dependent selection decision and strength of steel over the planning horizon.
Author Keywords: Carbon equivalent, recycled steel, modeling, strength of steel, stochastic.
C. Christopher Senfuka1, Paul Kizito2, J.B. John Kirabira3, and J.K. Joseph Byaruhanga4
1 Dept. of Mechanical & Production Engineering, Kyambogo University, Kampala, Uganda
2 Dept. of Mechanical & Production Engineering, Kyambogo University, Kampala, Uganda
3 Dept. of Mechanical Engineering, Makerere University, Kampala, Uganda
4 Dept. of Mechanical Engineering, Makerere University, Kampala, Uganda
Original language: English
Copyright © 2015 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Deciding the functional suitability of recycled steel using carbon equivalent (CE) and strength can be misleading since the formulae used to determine CE do not capture many of the elements that play a decisive role in establishing steel values. In this study, a mathematical model is developed to optimize the selection decision from a steel manufacturer considering a stochastic CE distribution. In the given model, a building/fabrication contractor intends to select one of two manufacturers of recycled steel bars basing on CE as determined by the IIW formula and strength values selected in equal monthly intervals. A Markov decision process approach is adopted where three states of a Markov chain represent possible states of CE of steel bars. The ultimate strength, σu, of steel is maximized for minimum CE where the decision to select the best steel is made using dynamic programming over a finite period planning horizon. A numerical example demonstrates the existence of an optimal state-dependent selection decision and strength of steel over the planning horizon.
Author Keywords: Carbon equivalent, recycled steel, modeling, strength of steel, stochastic.
How to Cite this Article
C. Christopher Senfuka, Paul Kizito, J.B. John Kirabira, and J.K. Joseph Byaruhanga, “Modeling Selection Criteria for Reinforcement Steel Bars with Stochastic Carbon Equivalent distribution,” International Journal of Innovation and Scientific Research, vol. 17, no. 2, pp. 370–380, August 2015.
