thnksss...but i was asking about the upper and lower yield points...the case of true engineeriing stress-strain curve and normal stress-strain curve arises only after the ultimate failure stage...
can you tell something regarding the reason as to why there are two yield points, upper and lower??
Sir, since you are concerned with the field of material science, may I ask a question in that regards??
I wanted to know why are there two yield points in a stress strain curve ?