Transdisciplinary Engineering Design Process

9Optimization in Design

The designer must consider the optimum solution to a design problem so that a better, more efficient, less expensive solution that is in harmony with the laws of man and nature can be achieved.

9.1 Introduction

Problems associated with optimum design have been the subject of considerable attention for a number of years. During the last several decades the field of optimum design has made remarkable progress in systems design, control of dynamics, and engineering analysis. With recent advances in the field of computer technology, many modern optimization methods have been developed, and designing complex systems with the optimum configuration has become possible within a reasonable computation time.

There are two kinds of effects inherently associated with any mechanical element or system:

1. Undesirable effects, such as high cost, excessive weight, large deflections, and vibrations.
2. Desirable effects, such as long useful life, efficient energy output, good power transmission capability, and high cooling capacity.

Optimum design can be defined as the best possible design from the standpoint of the most significant effects, that is, minimizing the most significant undesirable effects and/or maximizing the most significant desirable effects.

The application of optimization to a design problem requires formulation of an objective function such as weight, cost, or shape, and the expression of design constraints as equalities or inequalities. The objective ...