Date of Award


Degree Type

Capstone Project

First Advisor

Bahram Nassersharif


Designing a structure to demonstrate the strength of 3-D printed part is more complicated than it seems. The design goal was to construct a device that demonstrates how 3-D printing can create a strength optimized design. The design must incorporate maximum strength, while not sacrificing other major components such as weight of the product, cost of the product, print time of the product and how much material is being used. Extensive research and tests were conducted on infill patterns, football helmets, and TPU material (material used in football helmets).

There are multiple infill patterns that must be considered. The most important aspect of printing parts via FDM 3D printing is the infill pattern. This will directly affect the print time, material used, cost, and strength of the printed part. The second most important concept of the 3-D printed part is the infill structure. There are many infill structures, each having its own strengths and weaknesses when approaching higher strength, time to print, material used and weight. The team decided to focus on four commonly used infill structures (honeycomb, wiggle, triangular, and rectilinear). The team conducted a 3-point bending test and compression test, strictly following the ATSM standards to find out more about the strengths and weaknesses of each specific infill pattern (shown in this report). A design has been created and the application is a football Helmet. The design has 2 parts. The first part is a smaller, circular piece as the very top of the helmet. This piece contains a “triple layer infill sandwich.” The triple layer infill sandwich is composed of 3 different infills: wiggle infill (good for distributing rotational energy), honeycomb infill (good for distributing linear impact), wiggle infill again (good for distributing rotational energy). The second part of the helmet liner is a dome composed of an Isomax structure with a hole cut out at the top of the helmet.

The team originally came up with 120 different designs in an attempted to best solve the task at hand. The method from obtaining these ideas came from brainstorming and online research. To narrow the solutions, a table was made with different attributes and rankings with each attribute. The team went through each individual concept and ranked it accordingly. After we had our top ideas team 13 conducted specific testing to figure out which idea was best and team 13 came up with this specific helmet liner.


Sponsor: Raytheon Company