## Genetic Algorithms in Engineering Design

Gradient-based algorithms have some weaknesses relative to engineering optimization. Specifically, it is difficult to use gradient-based algorithms for optimization problems with:

- discrete-valued design variables
- large number of design variables
- multiple local minima, maxima, and saddle points
- nondifferentiable objectives and constraints
- analysis programs which crash for some designs

In recent years, a new family of optimization algorithms has emerged for dealing with the above characteristics. These algorithms are known as evolutionary algorithms. Evolutionary algorithms mimic the optimization process in nature as it optimizes biological species in order to maximize survival of the fittest. One type of evolutionary algorithm is the genetic algorithm. We will examine genetic algorithms in detail.

We express appreciation to Professor Richard J. Balling of the Civil and Environmental Engineering Department at BYU for allowing us to use this chapter.