Hello everyone!
Consider a single spring or beam fixed at one end and pulled at the other end. There are two static steps with NLGEOM - in the first one, the spring/beam is pulled with a boundary condition while in the second step, this boundary condition is deactivated and tensile force is applied to the same node instead. The problem is that this stretching in the first step has no influence on the results in the second step. Why is that so? From what I understand, the boundary condition deactivated in the second step should be replaced with an equivalent reaction force which is ramped down to zero throughout the step while the concentrated force applied in that step is ramped up. The spring should be stretched at the beginning of the second step when the tensile force is applied so the results should differ when compared with an analysis involving only the tensile force, with no pre-stretching. What am I missing here?

Abaqus ​​​​​​​