Stressed and Strained
Compression and tensionCopyright Image from How Stuff Works, Robert Lamb and Michael Morrissey, https://science.howstuffworks.com/engineering/civil/bridge2.htm
Accessed August 4, 2020
Students are introduced to the concepts of stress and strain with examples that illustrate the characteristics and importance of these forces in our everyday lives. They explore the factors that affect stress, why engineers need to know about it, and the ways engineers describe the strength of materials. In an associated literacy activity, while learning about the stages of group formation, group dynamics and team member roles, students discover how collective action can alleviate personal feelings of stress and tension.
Engineers use their understanding of forces, stress, strain and material properties to create safe designs for structures, equipment and products. Analysis of strength of materials (yield strength, ultimate tensile strength and fatigue strength) figures into the selection of materials used to create items such as chairs, appliances, toys, bicycles, medical joint replacements, rock climbing rope, door handles, roof shingles, water slides, diving boards, bridges and playground equipment, to name a few.
After this lesson, students should be able to:
- Recognize that engineers use their understanding of forces, stress, strain and material properties to create safe designs for structures, equipment and products.
- Explain how force and area affect stress.
- Distinguish between compression and tension.
- Describe several properties of materials.