What is the typical fatigue life of a helicopter airframe?
Typical helicopters do not have cycles or hours limits on the non-dynamic components.

Since they are not pressurised, there is no concept of "cycles" and the fuselage is neither stressed, nor subject to the same kinds of forces that airliners are.

They are inspected on fixed hours cycles and specific types might have areas which are subject to non-destructive testing in accordance with operator, manufacturer or regulatory instructions.  Some, most notably Robinsons, are rebuilt by the manufacturer on hours based cycles and return as new.  However, the fuselage and it's major components are not replaced.  They are inspected and refurbished.

The dynamic components are of course lifed but I see that you have a separate question for that.