Week 7-Long Piston With Cam

Objective- To perform a transient analysis on a piston and cam mechanism model. You need to run the analysis with Frictionless contact, Frictional with 0.1 and 0.2 as the frictional contact for a total of 3 cases. Find out the Equivalent Stress, Directional Deformation and Equivalent Elastic Strain and compare them for all the three cases.

Solution - First we add the material needed from the engineering library:

Material Properties for Structural Steel

Now we upload the model to the geometry and open it in space clam and see if there are any discontinuities in the model.

Now in connections we add contacts between the cam and the barrel and cam and cam shaft. The contact is kept as friction less.

We add the joints to the model fixed to ground for the barrel, revolute for the car shaft and translational for the cam follower.

We generate face sizing where there is contact with a mesh element size of 3 mm.

ANALYSIS SETTINGS

RESULTS

TOTAL DEFORMATION FOR CASE1

STRAIN FOR CASE1

STRESS

TOTAL DEFORMATION FOR CASE2

STRESS FOR CASE2

STRAIN FOR CASE2

DIRECTIONAL DEFORMATION FOR CASE3

STRESS FOR CASE3

STRAIN FOR CASE3

Conclusion: From the Average Deformation graph we find that the deformation doesn't seem to change much in each case. But at the peak of the graph there is slight difference in value. Peak is highest for frictionless case and lowest for friction 0.2 case.

From the stress-time graphs, we can see that stress is maximum when the coefficient of friction is 0.2 and least for frictionless contact.From here a basic infer can be made that due increase in friction, more work has to be done to overcome this increasing friction.Thus, giving rise to stress in contact areas.