Document Type
Thesis
Date of Award
5-31-1985
Degree Name
Master of Science in Mechanical Engineering - (M.S.)
Department
Mechanical Engineering
First Advisor
Sachio Nakamura
Second Advisor
Rong-Yaw Chen
Third Advisor
Bernard Koplik
Abstract
This Thesis studies optimal design of structural dynamics, based on the State Space approach which uses the Design Sensitivity Analysis and the Adjoint Variable Technique. As a numerical example, optimal design of a multistory structure subjected to a dynamic response, similar to that of an earthquake, is chosen. The equations of motion of the structural system are constructed using the Finite Element method, treating the cross-sectional area of each story as a design variable. To solve the equations a package program DE is used. A program is developed based on the State Space Algorithm and the cost function, constraints and the gradients are calculated using this program. The results are fed to the optimization package LINRM which, then, iteratively searches for the optimal solution in the design space.
The results obtained are fairly good, however there is some discrepancy with the exact results. A possible reason could be that there still exists a bug in our version of the LINRM package, which was still in the development stage at that time. Another reason could be that, in any optimal design exercise, there exist several optimal solutions in the design space. To find out one particular solution, one has to go through a lot of Trial and Error processes. Due to the limitations on time and computer resources, debugging of LINRM and developing global optimization algorithm are left out as future researches.
Recommended Citation
Khan, Azhar Imtiyaz, "Optimal design of a dynamic structural system" (1985). Theses. 3444.
https://digitalcommons.njit.edu/theses/3444
