Strain in Airplane Headrests
Independent Work
Fall 2023
Overview
-For my strength of materials final project, I wanted to connect the study to my senior capstone project (Projects). -
Adjustable headrests have different seat attachments than non-adjustable headrests; our design is adjustable. If a headrest extends more than 2 inches, which ours does, it must withstand a 25-pound abuse load (FAA regulations). We selected two 3/8-inch diameter 2.5-inch long aluminum rods as our headrest supports, which is relatively standard.
Theoretical Calculations
Using the mathematical principles of strength of materials, I calculated the greatest internal stresses and strains (the point at which the design could fail) occurred with a pulling force at 45 degrees to the headrest. I assumed the 25-pound load was evenly distributed, resulting in a 12.5 lb force on each headrest pole.
Experimental Testing
To experimentally test my results, I split the force into its x and y components and applied those forces to the rod (setup to left). Using the attached strain gage I measured the internal strain due to loading.
Findings
My experimental findings differed from my calculated values by only 2.5%, and were well within the strength capabilities of our design, verifying that the chosen supports will easily meet FAA regulations.