Dear all,
I'm designing a tall tower. While considering vortex shedding our client requires alternative stress to be limited to 85 MPa and number of cycles to be 1000,000. My questions are:
1.Is there any sentence in the code which these two numbers(85 MPa & 1000,000 Cycles) are mentioned?
2.If the answer to the first question is No, then, what is the criteria for acceptance of vortex shedding alternative stress and number of cycles?

I would say refer to ASME Sec. VIII Div. 2 and read the section on fatigue loading.