Transient analysis on a piston and cam mechanism

Objective :

To perform a transient analysis on a piston and cam mechanism model with Frictionless contact, Frictional with 0.1 and 0.2 as the frictional contact for a total of 3 cases and analyse the results .

Geometry:

Barrel cam ,Cam follower ( green )and Guide which supports the cam follower .

Material :

Barrel cam and the support guide were assigned Stiffness behaviour as rigid because we were not interested in its resuts are follower is the weakest part considering forces acting on it and its geometry.

Contact pairs :

Between the Guide and cam follower .

Between the Barrel cam and cam follower

Case 1: Frictionless contact

Case 2 : Frictional contact with frictional coefficient set to 0.1

Case 3 : Frictional contact with frictional coefficient set to 0.2

Applied joints :

Fixed joint assigned to guide

Revolute joint assigned to barrel

Body to body Translation joint assigned with guide set to Body and cam follower set to mobile .

Mesh :

Body mesh type default

Face mesh size of 3mm along the contact .

Analysis settings :

Rotational joint was assgned in 9 steps with degrees of rotation as follows :

Results :

Case 1 Frictionless

Equivalent stress

Equivalent strain :

Deformation

Safety factor :

Case 2: Frictional coefficient set to 0.1

Equivalent stress

Equivalent strain :

Deformation

Safety factor :

Case 3: Frictional coefficient set to 0.2

Equivalent stress

Equivalent strain :

Deformation

Safety factor :

Reports :

Case 1 Frictionless

Case 2: Frictional coefficient set to 0.1

Case 3: Frictional coefficient set to 0.2

Discussion :

• The deformation plot that we see considers maximum deformation throughout time .

So we observe that considering relative deformation

0.2mm<0.72mm<1.026mm

Case1 <case 2 <case 3

• Equivalent stress was observed maximum for case 3 at around 18108mpa
• Equivalent strain was observed maximum for case 3 at around 9.150e-2mm/mm
• Safety factor as expected was observed to be the least for

case 1 0.194

case 2 1.45e-2

case 3 1.38e-2

Conclusion:

Due to computation limit result for safety factor is not accurate but we can observe a trend from stress contours .

Analysis was successful and we observe how frictional coefficient plays an important part in designing cam and follower .