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.

Update the model to the mechanical module. And Opening the module.

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 cam shaft and translational for the cam follower.

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

Inside of the barrel is also meshed

For analysis settings we use total 9 steps for the 1^st step the settings are

For steps 2 to 8

Now we add a joint load of rotation type and input the rotation degrees

After setting up the problem insert the desired results in the solution and solve.

Friction less

Equivalent Stress

Equivalent strain

Directional Deformation

Frictional coefficient 0.1

Equivalent Stress

Equivalent strain

Directional Deformation

Frictional coefficient 0.2

Equivalent Stress

Equivalent strain

Directional Deformation

Comparison Table –

parameters	Units	Friction less	FC 0.1	FC 0.2
		Max	max	max
Equivalent plastic strain	mm/mm	0.008843	0.009605	0.011162
Total Deformation	mm	35.921	35.921	35.921
Equivalent stress	Mpa	1758.9	1850.2	2156.7
Directional Deformation	mm	11.095	11.133	11.167

Simulation Link –

https://www.youtube.com/watch?v=i__Kh2Gvw78

Model Link

https://drive.google.com/open?id=1j_JuZiyW6-d_VqWkJ7DGP33vx4bIPZ2Q

Conclusion - From the above table we can see that as the frictional co-efficient increases the equivalent stress, strain and Directional deformation increases. As there is friction the energy required also increases hence the stress and strain also increases. Total deformation remains constant for all three cases.

More force is required to over come the friction and force is directly proportional to stress thus the stress increases.

Stress is directly proportional to strain and thus strain increases.