Mechanical System Design (Strength and Stiffness)

Abstract

This chapter discusses the design of mecshanical systems, especially strength and stiffness. Strength—the resistance against irreversible deformation—must always be high. Here, we will discuss the design guidelines of strength, such as elasticity, by calculating the displacement, strain, and stress of mechanical parts due to loads. On the other hand, needs on stiffness—the resistance against reversible deformation—shall rely on their implementations. As a design guideline of stiffness, we will deal with the mechanical vibrations, which periodically happen about an equilibrium point, such as the movement of a pendulum or the (random) motion of a tire on a gravel road. However, as quantum mechanics advances, engineers understand that failure occurs through the material imperfections and transport of products. It is difficult to explain the traditional methods so that we need the parametric ALT based on quantum/transported time-to-failure prototype and sample size formulation.