Development of a GA-based method for reliability-based optimization of structures with discrete and continuous design variables using OpenSees and Tcl

This paper develops a method based on genetic algorithm (GA) for reliability-based optimization (RBO) of structures through a software application. This method employs GA as an optimization technique in which reliability constraints of RBO problem are evaluated using finite element reliability analysis modules offered by OpenSees. Since Tcl is a programmable and interpreted language, the proposed method is implemented using Tcl scripting language together with OpenSees software framework. Developing the RBO method through this software application leads to the important advantage of utilizing new advanced structural reliability methods implemented in OpenSees without compiling the source code. In the RBO problem, the cost of design is defined as an objective function and a number of design requirements are defined as reliability constraints. This method is also able to deal with RBO problems with discrete and continuous design variables. Six numerical examples are provided to investigate the strengths of the method through the software application. Results illustrate the advantages of this application in RBO of structures. Since OpenSees is used for finite element reliability analysis, this application is readily extendable to nonlinear structures.