The attached chart is used in the offshore pipeline industry where plastic deformation and straightening is common with e.g. reeling in cases up to 2.5%. DNV specifications allows up tp 5% by using material with the additional requirement P...
Allowable moment (M) for elastic deformation is calculated as M = Section modulus x allowable stress. How to calculate the moment for plastic deformation e.g. in a bending machine?https://files.engineering.com/getfile.aspx?folder=f973e879-ae02-4a6b-a9ee-001be79755f7&file=stress_strain.jpg