Mechanical Engineering Design
Mechanical design is a complex undertaking, requiring many skills. Extensive relation-
ships need to be subdivided into a series of simple tasks. The complexity of the subject
requires a sequence in which ideas are introduced and iterated.
We Frst address the nature of design in general, and then mechanical engineering
design in particular. Design is an iterative process with many interactive phases. Many
resources exist to support the designer, including many sources of information and an
abundance of computational design tools. The design engineer needs not only to develop
competence in their Feld but must also cultivate a strong sense of responsibility and
professional work ethic.
There are roles to be played by codes and standards, ever-present economics, safety,
and considerations of product liability. The survival of a mechanical component is often
related through stress and strength. Matters of uncertainty are ever-present in engineer-
ing design and are typically addressed by the design factor and factor of safety, either
in the form of a deterministic (absolute) or statistical sense. The latter, statistical
approach, deals with a design’s
and requires good statistical data.
In mechanical design, other considerations include dimensions and tolerances,
units, and calculations.
The book consists of four parts. Part 1,
begins by explaining some differ-
ences between design and analysis and introducing some fundamental notions and
approaches to design. It continues with three chapters reviewing material properties,
stress analysis, and stiffness and de±ection analysis, which are the key principles nec-
essary for the remainder of the book.
consists of two chapters on the prevention of failure of
mechanical parts. Why machine parts fail and how they can be designed to prevent fail-
ure are difFcult questions, and so we take two chapters to answer them, one on pre-
venting failure due to static loads, and the other on preventing fatigue failure due to
time-varying, cyclic loads.
In Part 3,
Design of Mechanical Elements,
the material of Parts 1 and 2 is applied
to the analysis, selection, and design of speciFc mechanical elements such as shafts,
fasteners, weldments, springs, rolling contact bearings, Flm bearings, gears, belts,
chains, and wire ropes.