Date of Award

Winter 2009

Document Type


Degree Name

Doctor of Philosophy (PhD)


Mechanical & Aerospace Engineering


Mechanical Engineering

Committee Director

Gene Hou

Committee Member

Han Bao

Committee Member

Anthony Dean


In the early stages of design when data availability is limited, engineers often times rely upon experience and regression analysis to select the most suitable design equation among many competitive ones. This study presents an alternative that applies a modified Analytical Hierarchy Process (AHP) to select the most suitable design equation. The Analytical Hierarchy Process, a multi-criteria decision making method, has been utilized in the business and management world to collect and evaluate experts' opinions in order to arrive at a final decision. The Analytical Hierarchy Process employed here will treat each of the design equations as an expert and allow the decision maker to evaluate and weight the opinions of the experts. Selecting an impact pressure equation among seven semi-empirical and three classification societies' design equations for planing hull design is used as an example to facilitate the study presented in this dissertation.

The criteria and their associated weights that make up the decision making hierarchy of the Analytical Hierarchy Process are first established, with which the overall weighting coefficients can be computed to rank the candidate design equations. A preview sensitivity analysis is applied to screen out unfavorable design equations. The Analytical Hierarchy Process is then applied to select the most suitable impact pressure equation for twenty planing hulls. Next, a post sensitivity analysis is applied to ensure the robustness of the decision process. The results of such selection are compared with those of full scale test data. The implemented Analytical Hierarchy Process accurately selects the optimal pressure equation for fifteen of the twenty test cases. While it fails to select the best pressure design equation for the other five cases, it does provide recommendations that can lead to the selection of the right design equation.

This study has demonstrated that the Analytical Hierarchy Process holds potential to be effective not only in selecting a suitable pressure equation for planing hull design but also in finding the strengths and the weaknesses of each of the pressure equations under consideration.


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