Title: Material selection for light-weight naval crafts using the modified digital logic method: dealing with ranking abnormalities

Authors: J.B. Torrez; A.S. Milani; D.D.C. Schuetze

Addresses: Department of Civil and Environmental Engineering, and Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. ' Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; School of Engineering, University of British Columbia, 3333 University Way, Kelowna, BC V1V 1V7, Canada. ' School of Engineering, University of British Columbia, Kelowna, Canada

Abstract: The modified digital logic (MDL) weighting technique along with the weighted-sum-method (WSM) is applied to a material selection problem for light-weight naval crafts. Both the standard linear and non-linear normalisation schemes have been applied on a selected set of material properties. A ranking abnormality analysis is conducted to examine the robustness of the selection process. It is believed that the MDL method can be effective in similar applications, owing to its simplicity in finding the criteria weights through pair-wise judgements by the designer. In order to make the selection method more robust, it is suggested to define a set of fixed scaling factors in normalising the material data, rather than using maximum or minimum values of each decision matrix. The implementation of the fixed scaling factors for normalisation can significantly reduce the abnormality in ranking results as shown in the performed case study.

Keywords: multicriteria materials selection; lightweight naval craft; modified digital logic; linear normalisation; nonlinear normalisation; ranking abnormalities.

DOI: 10.1504/IJMSI.2012.049958

International Journal of Materials and Structural Integrity, 2012 Vol.6 No.2/3/4, pp.241 - 256

Published online: 18 Sep 2014 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article