Composite Materials lab

Charisse A. Nelson and Sarah Wigodsky

This week we completed tension testing for our 1%, 5%, and 10% Hemp Composites samples and then created stress vs. strain graphs for each. From the graphs we were then able to determine the average modulus as well as the average ultimate stress. While the sample size was small the data is consistent with existing composite research. The 10% composite had the longest average modulus and thus was stiffer due to the additional hemp fibers while the 1% had the highest ultimate peak. After completing our analysis we moved on to prepping our accidental hemp foam composites as they offered new information. In order to get the samples ready for testing we: drilled out 10mm samples with the drill press and then used the precision saw and polisher to trim them down to 5mm samples. From there we looked at 3 samples from the 5% and 10% underneath the optical microscope to see the size of the air cells and how the hemp fiber moved in relation to those cells. The 1% was not used as it never foamed. Next week we will conclude our experimentation by compressing the remaining samples using static and dynamic compression.

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Stress vs Strain Comparison for 1% Hemp Composite

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