Students are introduced to the five fundamental loads: compression, tension, shear, bending and torsion. They learn about the different kinds of stress each force exerts on objects.
Through a series of three lessons, each with its own hands-on activity, students are introduced to 1) forces, loads and stress, 2) tensile loads and failure, and 3) torsion on structures—fundamental physics concepts that are critical to understanding the built world. The associated activities engage students through experimenting with hot glue gun sticks to experience tension, compression and torsion; the design of plastic chair webbing strips; and problem-solving to reinforce foam insulation "antenna towers" to withstand specified bending and twisting.
This lesson focuses on torsion as a force acting upon structures. Students will have the opportunity to design something to withstand this force.
Open textbook in statics and dynamics for engineering undergraduates. Covers particles and rigid bodies (extended bodies), structures (trusses), simple machines, kinematics, and kinetics, as well as introductory vibrations. Includes text, videos, images, and worked examples (written and video).
Students are introduced to static equilibrium by learning how forces and torques are balanced in a well-designed engineering structure. A tower crane is presented as a simplified two-dimensional case. Using Popsicle sticks and hot glue, student teams design, build and test a simple tower crane model according to these principles, ending with a team competition.
Students reinforce an antenna tower made from foam insulation so that it can withstand a 480 N-cm bending moment (torque) and a 280 N-cm twisting moment (torque) with minimal deflection. During one class period, students discuss the problem, run the initial bending and torsion tests and graph the results. During the following class periods, students design, construct and test sturdier towers, and graph the results.