## General Mechanical

#### Urgent-How to convert fatigue results from cycles into days?

• mwardeh
Subscriber

Hello,

I am using ANSYS AIM 18.1 for conducting fatigue analysis using the defined structural template of steel.

I have gotten the results below and am not able to convert fatigue life from cycles into days.

Please not I have completed my PhD defense and my committee members are requesting these info by tomorrow.

Thanks,

Muhammad Wardeh

PhD Candidate in Mining Engineering

Department of Mining and Nuclear Engineering

Missouri University of Science and Technology
mawc6f@mst.edu
256-683-2461

• Sandeep Medikonda
Ansys Employee

Muhammad,

Are you doing a vibration based fatigue or a time-based fatigue? For the later if each cycle has certain time period, can't we just calculate it?

Regards,
Sandeep

• peteroznewman
Subscriber

Hello Muhammad,

It looks like you have a cable wrapped around a pulley. What is your definition of a cycle?

One definition could be for a point on the cable to go round the pulley once. That means the cable goes from straight to wrapped to straight.

How many times a day does that happen?

An example would be if the one point went around the pulley one time each minute and the machine ran for 8 hours a day. That is a total of 8 x 60 = 480 times/day.

So if ANSYS calculates the minimum life is 2.85e5 cycles, just divide by 480 to get a minimum life of 593 days.

Hope that helps (I tried to call your phone but you didn't pick up).

Regards,
Peter

• Sandeep Medikonda
Ansys Employee

Muhammad, Since this is a public forum. I've removed the address from your post for your own safety. I would recommend against doing so in the future as well.

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