Before revision: The , and are defined as linear functions of the absorbed hysteretic energy : The pinching function is specified as: where: and is the ultimate value of , given by Observe that the new parameters included in the model are , where : , , , , , , , , , and .
After revision: The , and are defined as linear functions of the absorbed hysteretic energy : The pinching function is specified as: where: and is the ultimate value of , given by Observe that the new parameters included in the model are , where , p, q, , and are the pinching parameters : , , , , , , , , , and .