this assumes a ductile material. I myself am smiling as though everything is fine in the elastic region and may snap at any moment.
Past the elastic deformation region / yield stress you get plastic deformation, which even when the stress is completely removed there is permanent deformation.
Gotcha. Thanks! Do the points P, E, Y, U, and F stand for something or are the letters arbitrary?
Plastic deformation point, elastic deformation point, yield point, ultimate strength, and failure point
E is where it stops being linear, Y is yield, U is ultimate as in max, and f is fracture / failure. Not sure about p.
P is the Proportional Limit, where it stops being linear, but remains elastic for a short while longer, meaning any deformation can still be recovered. E is the Elastic Limit, where it changes from elastic to plastic
Everything past the dotted line is the point where the material won't go back to its original shape.
Example: You can push on the hood of your car all you want, it'll flex, and go back to its original shape (elastic deformation); but stand on it, and it'll dent (plastic deformation).
Manager "So all that you need is more strain to reduce the stress? Here are 10 more tasks which should strain you quite a bit"
The material is too ductile. I am at the peak of a narrow yield curve and then, snap, material breaks.