3D Printed Bridge

The goal of this project was to design a bridge in Solidworks, construct it using 3D printed PLA, and test it by increasing its load until it broke. The bridge could not have a mass greater than 40 grams, have a length longer than 9.75 inches, or a width greater than 2.5 inches. The bridge had to span a gap of 9 inches, have an open area of 2 inches by 2 inches in the middle, and have a hole in the middle of the roadbed for the testing apparatus. The max height of the bridge was 4 inches from the bottom, the smallest feature size was 2 mm in all directions, and our bridge was not allowed to have any parts below the top plane of the supports on the testing apparatus.

Initial bridge Design

Modified Warren Bridge

Final Custom Bridge

Stress Analysis

Displacement

3D Printed

Not printed as design did not meet the weight requirement

From this project, lessons about material selection, level of trust from FEA, and the process of continuous improvement were learned. There were many cases where the FEA simulation and physical testing results were different, and odd situations where adding or removing in certain parts of the bridge would result in unexpected changes elsewhere in the bridge during testing. Surprisingly, adding thicker beams and filets made more of a difference for reducing stress in some cases than adding more beams, which contradicted mathematical load calculations. The results from the testing of the final design are shown below.

Page updated

Report abuse