Optimal Design of Latticed Towers Subjected to Earthquake Loading
Publication: Journal of Structural Engineering
Volume 128, Issue 2
Abstract
The problem of optimal design of latticed transmission towers subjected to normal operating loads and an earthquake load is formulated. A time history analysis of the structure is performed. The constraints given in a design code are imposed. Many of the constraints are time dependent; therefore methods to treat them are incorporated in the solution process. All members are treated as equal- (unequal-) legged angle sections. The members are selected from the sections available in a manufacturer’s catalog. Two methods are presented and evaluated for such discrete variable optimization problems. The first method, called the two-phase method, uses a combination of continuous and discrete optimization algorithms, and the second one, called an adaptive discrete assignment method (ADAM), uses only a continuous optimization algorithm. The proposed methods are applicable to any discrete variable problem that can be formulated as a continuous problem. In addition, the problem is solved using a genetic algorithm (GA). The efficiency and practicality of the proposed methods are compared to those of the GA. From the results, it is concluded that the GA is a very straightforward method to use for discrete problems; however, it requires a significant amount of Central Processing Unit time. On the other hand, the two-phase method and the ADAM do not require as much computational effort but the discrete designs found with them are slightly more expensive. Also, numerical implementation of the two methods requires more effort.
Get full access to this article
View all available purchase options and get full access to this article.
References
American National Standards Institute (ANSI)/ASCE. (1992). Design of latticed steel transmission structures, ASCE, Reston, Va.
Arora, J. S. (1989). Introduction to optimum design, McGraw-Hill, New York.
Arora, J. S., Editor (1997). Guide to structural optimization, ASCE, Reston, Va.
Arora, J. S. (1999). “Optimization of structures subjected to dynamic loads.” Structural dynamic systems: Computational techniques and optimization, C. T. Leondes, ed., Vol. 7, Gordon and Breach, Newark, N.J., 1–73.
Arora, J. S., and Huang, M. W.(1996). “Discrete structural optimization with commercially available sections.” J. Struct. Mech. Earthquake Eng., 13(2), 93–110.
Arora, J. S., Huang, M. W., and Hsieh, C. C.(1994). “Methods for optimization for nonlinear problems with discrete variables: A review.” Struct. Optim., 8, 69–85.
Arora, J. S., Lin, T. C., Elwakeil, O. A., and Huang, M. W. (1993). “IDESIGN 4.2 user’s manual.” Technical Rep. ODL-93.04, Optimal Design Laboratory, Civil Engineering, Univ. of Iowa, Iowa City, Iowa.
ASCE. (1990). Design of steel transmission pole structures. 2nd Ed., ASCE, Reston, Va.
Borusan (1997). “Structural steel profiles” Borusan Boru Product Catalog, Borusan Holding A. S., Istanbul, Turkey.
Camp, C. V., Pezeshk, S., and Cao, G.(1998). “Optimized design of two-dimensional structures using a genetic algorithm.” J. Struct. Eng. , 124(5), 551–559.
Groenwold, A. A., and Stander, N.(1996). “A pseudo-discrete rounding method for structural optimization.” Struct. Optim., 11(3/4), 218–227.
Groenwold, A. A., Stander, N., and Snyman, J. A.(1997). “Optimal discrete sizing of truss structures subject to buckling constraints.” Struct. Optim., 14, 71–80.
Groenwold, A. A., Stander, N., and Snyman, J. A.(1999). “A regional genetic algorithm for the discrete optimal design of truss structures.” Int. J. Numer. Methods Eng., 44, 749–766.
Huang, M. W. (1995). “Algorithms for mixed continuous-discrete variable problems in structural optimization.” PhD dissertation, Dept. of Civil and Environmental Engineering, Univ. of Iowa, Iowa City, Iowa.
Huang, M. W., and Arora, J. S.(1997a). “Optimal design of steel structures using standard sections.” Struct. Optim., 14, 24–36.
Huang, M. W., and Arora, J. S.((1997b). “Optimal design with discrete variables: Some numerical examples.” Int. J. Numer. Methods Eng., 40, 165–188.
Kocer, F. Y. (1998). “Optimal design of nonlinear structures subjected to dynamic loads with application to transmission line structures.” PhD dissertation, Dept. of Civil and Environmental Engineering, Univ. of Iowa, Iowa City, Iowa.
Kocer, F. Y., and Arora, J. S.(1996a). “Design of prestressed concrete transmission poles: Optimization approach.” J. Struc. Eng., 122(7), 804–815.
Kocer, F. Y., and Arora, J. S.(1996b). “Optimal design of steel transmission poles.” J. Struct. Eng., 122(7), 1347–1357.
Kocer, F. Y., and Arora, J. S.(1997). “Standardization of steel pole design using discrete optimization.” J. Struct. Eng., 123(3), 345–349.
Kocer, F. Y., and Arora, J. S.(1999). “Optimal design of H-frame transmission poles for earthquake loading.” J. Struct. Eng., 125(11), 1299–1308.
Mondkar, D. P., and Powell, G. H. (1975). ANSR general purpose program for analysis of nonlinear structural response, Univ. of California, Berkeley, Calif.
Natarajan, K., and Santhakumar, A. R.(1995). “Reliability-based optimization of transmission line towers.” Comput. Struct., 55(3), 387–403.
Pezeshk, S., Camp, C. V., and Chen, D.(2000). “Design of nonlinear framed structures using genetic optimization.” J. Struct. Eng., 126(3), 382–388.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 128 • Issue 2 • February 2002
Pages: 197 - 204
Copyright
Copyright © 2002 American Society of Civil Engineers.
History
Received: Aug 29, 2000
Accepted: Jul 11, 2001
Published online: Feb 1, 2002
Published in print: Feb 2002
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.