Transient Structural automatically has Large Deflection turned on. You can see that under Analysis Settings. That is one form of nonlinearity called geometric. You also have another form of nonlinearity called frictional contact. The third form of nonlinearity is in the material model, where there are many nonlinear material models such as hyperelasticity or plasticity.

Glad to hear your model is working. If your original question was answered, click on Is Solution under the post that best answered the question. Open a New Discussion for any new question.