Piston and cam mechanism analysis

AIM- To perform a transient analysis on a piston and cam mechanism model with frictionless contact, Frictional with 0.1 and 0.2 as the friction coefficients.

Material- For all the components of the piston and cam mechanism structural steel is taken as the material.

Analysis setup-First the Cad model is imported into the Ansys and structural steel is assigned to all components of the piston and cam mechanism by default.

-After the assignment of the material, frictionless contact is provided between the follower-cam and piston-barrel to perform the first analysis. These 2 contacts can be seen below-

-Now three joints (fixed, revolute and transitional) are provided which can be seen below-

-After providing the joints, mesh is generated and face sizing is done at cam groove surface and followers spherical surface by providing the element size of 2mm.

-Analysis settings are changed like number of steps to 9, changing weak spring setting to program controlled etc as it is done in the video. Boundary condition is provided by providing rotation to the cam.

-After the boundary conditions are provided analysis is run to get the results.

-Now this analysis setup is used for other cases by just changing the frictionless contact to the frictional contact of 0.1 and 0.2 friction coefficient.

Results-In this we determine the results for all the three cases like directional deformation, equivalent stress etc.

	Frictionless contact	Frictional contact with 0.1 friction coefficient	Frictional contact with 0.2 friction coefficient
Directional deformation
Equivalent stress
Frictional stress at contacts
Equivalent elastic strain

Interference on the basis of the results-

Directional deformation- It is increasing very less as we increase the friction coefficient value. Because as friction coefficient value increases the roughness also increases and follower ball stick more to the cam groove and movement is resisted more due to friction. Due to this, stem of the follower bends more and directional deformation increases. To see the bend in the stem of the follower, video is also attached with this report.

Equivalent stress- Stress in the follower keep on increasing as we increase the friction coefficient values. As we have also seen that the value of frictional stress at the contact increases with increase in the friction contact. So as the friction coefficient value increases it will try to resist more the movement of follower and thus the stress develops at the stem of the follower which can be seen below-

Equivalent elastic strain- For the same reason which is given in the equivalent stress, the equivalent elastic strain value also increases.