Doctoral Dissertations


Dan Li


"The goal of this research is to develop a constrained multiobjective optimization method in the form of a robust, practical, problem-independent algorithm, and to investigate the effect of multiobjective optimization on structural design.

This research studies the properties and characteristics of multiobjective optimization and solutions. Design objectives, constraints and design variables as well as their effect on structural design and behaviors are investigated. Dynamic input energy for a multidegree-of-freedom structure is formulated. A multiobjective optimization algorithm based on game theory is developed. Fuzzy set theory is introduced to construct a fuzzy constrained environment. A Pareto genetic algorithm is developed based on a simple genetic algorithm. Two new genetic algorithm operators – multiobjective fitness function and niche method – are proposed. A new genetic algorithm process – Pareto set filter – is added to genetic algorithms. Finally, a multiobjective optimization algorithm, which is robust and performs uniformly well on a broad range of problems, is developed with genetic algorithm, fuzzy logic and game theory.

Six frame structures and five truss structures have been optimally designed with static load, seismic excitation, and active control. Materials for the structures are steel, reinforced concrete, and a combination of both. Optimization goals cover weight, structural cost, displacement, strain energy, input energy, potential energy, and performance index. Constraints include stress, displacement, frequency, and ratio of story stiffness. The numerical results show that the newly developed algorithms can locate a global solution and Pareto optimum set which are usually difficult to find"--Abstract, page iii.


Cheng, Franklin Y.

Committee Member(s)

LaBoube, Roger A.
Belarbi, Abdeldjelil
Keith, Harold D. (Harold Dean), 1941-
Liou, Frank W.


Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering


National Science Foundation (U.S.)


Financial support from the National Science Foundation grants MSS-9214664 and CMS-9520804

Electronic access to the full-text of this document is restricted to Missouri S&T users. Print thesis not available at Missouri S&T Library.

Print thesis lost & withdrawn; scan made from microfilm is best quality available.


University of Missouri--Rolla

Publication Date

Fall 1997


xiv, 204 pages

Note about bibliography

Includes bibliographical references (pages 194-203).


© 1997 Dan Li, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Structural analysis (Engineering) -- Mathematical models
Earthquake resistant design
Genetic algorithms

Thesis Number

T 7430

Print OCLC #


Electronic OCLC #