I am having trouble understanding the difference between elastic limit and yield stress. I searched the internet for a few hours and found some conflicting answers. I have found 3 (maybe) different answers:
From the elastic limit to the yield point, the material is transitioning from elastic to plastic. This area is called the elastoplastic region. I got this conclusion from here.
The yield point is the same as the elastic limit. The yield point is only found in the elastic point which is impractical to find precisely. I got this conclusion from here.
The elastic limit is where the elastic region ends and the yield stress is just where a permanent deformation of 0.2% is formed. I got this conclusion from here and here. This runs counter to what I am told by my lecturer which is that the yield stress is where the elastic and plastic region is separated.
So far, I have 3 answers answering the same question. Which one is the actual answer? Thank you