Deep rolling tool and method

A method comprising:

• supporting a workpiece in a fixture, the workpiece having a first nonplanar surface:
• and
• performing a first rolling operation on the first nonplanar surface, the first rolling operation comprising:
• applying a downward force to a proximal end of a spring-loaded tool shaft aligned with a first axis, the downward force applied along the first axis such that the downward force is transferred through the shaft to a hub disposed at a distal end of the shaft assembly;
• transmitting the transferred downward force from an upper portion of the hub aligned with the first axis to a lower portion of the hub parallel to a second axis, the second axis forming a nonzero angle relative to the first axis, about which a roller disk is supported by one or more bearings, such that a resulting compressive force is applied to the first nonplanar surface of the workpiece via a working surface of the roller disk;
• and
• operating a load cell disposed along the first axis to generate signals corresponding to an instantaneous load on the spring-loaded tool shaft.