How to get copyright permission?

Hello all,

I am writing a scientific article and would like to use two figures from the Abaqus documentation (Figs. 23.2.2-7 and 23.2.2-9 from Abaqus Analysis User's Guide) in my article. Since the Abaqus documentation is an open access document and the figures are just describing a calibration process, do I need an official written permission for using them? No need to say that the figures are referred to the Abaqus documentation with proper reference marks in the article. I would be grateful if anyone could help me regarding this issue.

BR,

Mohammad