ABSTRACT
This chapter discusses different kinds of loading: static loads, repeated loads, impact, and shock. Ductile materials, having more than 5% elongation, exhibit somewhat different modes of failure than do brittle materials. Static loads, repeated loads, and shock loads produce different modes of failure. The chapter describes the conditions that must be met for satisfactory application of the direct stress formulas. It discusses the relationship among the terms “design stress,” “allowable stress,” and “working stress”. By testing materials under repeated loads, the stress at which failure will occur can be measured. Students will learn to perform the basic calculations for simple loads with regard to the resulting stresses and deformations, both of which are critical to ensuring safety and performance of student's designs. The failure modes for parts subjected to impact or shock loading are quite complex. Stress concentrations are most damaging for dynamic loading such as repeated loads, impact, or shock.
