Can anyone explain me how the load is applied to a metal specimen during tensile test? I am confused because I read in my textbook that after the ultimate stress is achieved and if the load is continued, then the metal specimen fails. But from the stress-strain diagram, we can see that the stress is decreased (the y axis) after ultimate tensile strength. Why is it decreased if we maintain the same stress? To be clear my question is that is the load applied in Universal Testing Machine is constant or not? I mean is the load uniform over time? thanks in advance.