Hello, members.

I would like to use the constitutive model for concrete by Tao (2013), which has a descending part after the maximum stress on the stress-strain relationship.

When I am using a theoretical constitutive model, as an example I can use the constitutive model present on the Eurocode, illustrated below. Is it necessary to convert theoretical stress-strain curves to true sreess-strain curves?

I wonder if any member could help me.

I have created the new topic  here