The Florida Prep Engineering class, under the tutorage of Mr. Turner, has recently been looking at different styles of construction and how failure analysis can be used to redesign and improve structures. One of their recent challenges was to build a self-standing stage, with a specification that each inch of their model represented one linear foot in the real world.
Students could use tongue depressors, balsa wood, and toothpicks as their main construction pieces. They could not simply stack layers of wood together. In addition to building a physical model, each student made an orthographic engineering drawing of their stage.
Each step of the process was evaluated on a variety of criteria, including appearance, safety, and accessibility. The most important criteria were the ratio between the dead load and the live load. The dead load is the weight of the stage itself and the live load is the weight that the stage can support without breaking.
After the construction phase, the class took the stages to the gym to put their stages to the test. Such was the weight load they were hard pressed to find suitable weights!
Each stage first had to hold ten pounds, and then incrementally forty-five-pound weights were added until the stage collapsed. This year, the stage that held the most weight held 685 pounds. Considering the stage itself weighed less than one pound that is quite a feat!
Following the stress test experiment, students analyzed their structures and looked at why and where they failed. Students had to decide what type of stress caused to it fail: torque, compression, tension, shearing, etc. and how they could redesign their structure to prevent that type of stress.
Looking ahead, the Engineering semester project will be to design a new dormitory for the school. Students must choose the location, decide on a layout, analyze how it will affect daily life at the school, and how to make the building energy efficient; they will be using computer-assisted design programs to help with the blueprints.
They will then construct a three-dimensional model as well as hand-drawn orthographic drawings of their design. The finished project will then be ‘sold’ to an invited audience of judges during a sales presentation.