Design of Mechanical Elements

1Mechanical Design

1.1 Introduction

In this chapter, we describe the basic concepts of mechanical design. Mechanical design is the branch of mechanical engineering that is concerned with the design of things and systems of a mechanical nature. It covers many different aspects of engineering and is highly interdisciplinary. Mechanical design is the process by which we attempt to satisfy a specific set of requirements to achieve an optimum outcome and functionality. Figure 1.1 schematically illustrates this concept. The mechanical design process starts from an initial conceptual idea, after which the idea is iteratively refined until all requirements have been satisfied.

These specific requirements or design specifications can include, e.g. cost, weight, strength, reliability, appearance, among many other requirements that we may need to consider. Sometimes, the requirements can be ambiguous, or even conflicting. For instance, “appearance” might be an ambiguous requirement because it is difficult to quantify. On the other hand, reducing weight while simultaneously increasing strength, or reducing cost while increasing reliability, are examples of conflicting requirements. Thus, the design process typically generates a multitude of solutions that satisfy the design specifications and no unique outcome exists.

1.2 Mechanical Design Process

Figure 1.2 schematically depicts the different phases of the mechanical design process.¹ The feedback loops emphasize the iterative nature ...