## Solidworks Shrink fitting of Cylinders

Shrink fitting is done on cylinders for the purpose of reinforcement against extensive internal pressures that may be a result of high pressure flows through the cylinders. Shrink fitting also helps cylinders cope with extensive external pressures acting on them.

It is, therefore, imperative that the designer or engineer can determine the stress due to shrink fitting and the probable effects on the cylinder walls to avoid possible failure.

Shrink fitting sets up a contact pressure at the interface of the two cylinders. This is equivalent to the radial stresses acting on the cylinder at this point. We will set up a simple demo on how we can do a shrink fit using SOLIDWORKS. Begin by creating the two cylindrical geometries.

Remember that there has to be a difference between the outer diameter of the internal cylinder and internal diameter of the outer cylinder in order to set up the interference. The latter should be greater than the former.

I went with the sketch below for the outer cylinder.

The extra surface acts as the support where we will define our fixed support.

For the inner cylinder, let use the above geometry shown as example.

We then set up the assembly and define the appropriate constraints (coincident and concentric mates).

Running the interference detection tool in the evaluate tab we notice that SOLIDWORKS automatically identifies an interference at the interface between the two cylinders. Go ahead to setup the static simulation. Remember to enable the SOLIDWORKS simulation add-in in the SOLIDWORKS add-ins folder.

Setup the fixed geometry as shown.

Next, define the contact set as a shrink fit and select the outer face of the inner cylinder and inner face of the outer inner to define the parameters of the shrink fit.

Next, define the material of the inner and outer cylinders and run the analysis.

From the von Mises stress plot we can tell points of maximum stress. We will be able to check the displacement of the cylinders due to contact pressure.