Sampat Kumar
Ansys Employee

When using beam elements for the axle instead of solid elements, you’ll face limitations in your contact definition. Beam elements can only have bonded connections with assemblies, while solid elements can use both bonded and frictional contacts. This is why you can’t achieve the desired frictional contact when using beam elements for the axle and solid elements for the slots.

To tackle this problem, you may need to represent the axle using solid elements in order to define the frictional contact between the axle and slots, since frictional connections won’t be sufficient in this case.

follow the following courses for more in details. 
Connecting Bolts with the Rest of an Assembly | Ansys Courses