Origami Challenge: Mechanical Properties of Paper Structures
Explore the engineering process through the application of forces and redesign of CAD files.
After completing this lesson, students will be able to:
a. determine the normal force applied by a weight on different structures
b. design vector images in CAD to be laser scored onto a piece of paper
A truss is a system of interconnected triangles that enable structures to support heavy loads, also known as forces. You have probably encountered trusses many times throughout the day already! They are commonly used to support roofs, floors and bridges.
Triangles are essential to the formation of a truss because of their unique geometric properties; compared to triangles, no other shape can achieve a greater strength using the same amount of material. As you know, a triangle is a three-sided polygon with angles that are held in place by the side that is opposite of it. This fact contributes to the rigidity that a triangle adds to the structure it forms, which means if a force is applied anywhere on the triangle, the angles of the triangle will not change. This rigidity creates a stabilizing effect that is important in the structure of a truss. Furthermore, when a force is applied to a triangular structure, the force is distributed sideways instead of straight down, which prevents the structure from bending. Lastly, since the center of the triangle does not contribute to the stability of the triangle, it can be left open, which minimizes the weight and fabrication costs of the resulting structure.