How can I estimate the fatigue life of a component subjected to a rotating cam?

[chandran]

I am working on a physics problem in a project to estimate fatigue life of a component.

There is a cam rotating with an offset of 10mm rotating at an rpm of 230. The component is a cantilever fixed at one end is getting hit by this cam while it is rotating. The cam is at the other end of cantilever.

I want to simulate this using basic mechanics to estimate the fatigue life of the component. So far i have done the following

1.peak acceleration due to the component is a(sqr w) where a is the cam offset and w is the frequency of rotation of cam. Call this peak acceleration as A

2.I have calculated the static stresses(principal stress(sigma) and maximum shear stress(tau)) at the cantilever point(fixed end) due to a load of P as sigma


After that how should i proceed to check the fatigue life?

 

[FredGarvin]

First thing you can do is to take your alternating stress and compare that to what can be found in S-n diagrams for the material your beam is made out of. That I would think would be the quickest and easiest. If your material has a fatigue limit, you will find it there.

 

[ravenprp]

To estimate the fatigue life of a component, you will need to consider several factors such as the material properties, loading conditions, and stress levels. The first step would be to determine the stress cycles that the component will experience due to the rotating cam. This can be done by calculating the stress amplitude, which is the difference between the maximum and minimum stress levels experienced by the component.

Next, you will need to determine the material's fatigue properties, such as the fatigue strength and fatigue limit. These values can be obtained from material data sheets or through experimental testing.

Once you have the stress amplitude and fatigue properties, you can use a fatigue life prediction method, such as the S-N curve or the Goodman diagram, to estimate the fatigue life of the component. These methods use the stress amplitude and fatigue properties to predict the number of cycles the component can withstand before failure.

It is also important to consider any potential stress concentrations or notches in the component, as these can significantly affect the fatigue life. If there are any stress concentrations, you may need to apply a stress concentration factor to your calculations.

In summary, to estimate the fatigue life of a component, you will need to determine the stress cycles, material fatigue properties, and use a fatigue life prediction method to calculate the expected life of the component. It is always recommended to validate your calculations through experimental testing or by comparing them to similar components with known fatigue life.