It took a long while, but a few weeks ago I finally removed the last bugs out of my force-extension machine’s code, and testing could commence. I focussed initially on creep, a phenomenon that occurs in the thermoplastics that we 3D print with. This phenomenon has not been investigated very much yet, and I hope to change that.
If you want to get the full story, please see the video below. Further down I will put the main results and links to the raw data. If you have any suggestions, questions, or comments, please leave them under the Youtube video, or e-mail them to firstname.lastname@example.org
The machine puts the sample under a predetermined amount of load, and then stops. Over the time force recorded by the machine will decrease due to creep. I investigated PLA using stresses up to 57.5 megapascals. Samples were left for 4 hours after initial loading.
You can find all of the data, processed and raw, and the python code used for analysis here.