I am new user of abaqus. I want to study the effect of cross head velocity and different strain rate on flow stresses developed in a material. Based on leterature survey, many people used abaqus for this purpose. I created rectugular ASTM specimen in abaqus and while applying boundry condition i fixed one end all DOF and another end i want to give displacement witgh repect to time or constant linear velocity. So how to give dispacment with respect to time or constant linear velocity boundry condition. And also if i want to study the post necking analysis then how to do that. Please if any one suggest me how to do that then its really helpful for my project.