Week 7-Long Piston With Cam

In this following long piston cam mechanism we will be discussing three different cases for the simulation based on the frictionless and frictional contact between the cam follower and barrel and piston cam and barrel respectively viz:

Objective:To analyze the deformation on cam and barrel and corresponding stress generated with different frictional co effecient

i) Frictionless 

ii) Frictional Contact 0.1

iii) Frictional Contact 0.2

GEOMETRY:

The Geometry for the following transient analysis are as given below:

                                                   Fig.Long piston cam Mechanism

In the following geometry the shaft will drive the piston through which the inner barrel is supposed to move inside out due to which there will be frictional or frictionless contact 

CASE 1: Frictionless Contact

For the following case here is the contact as below:

                                                  Fig.Long Piston Cam Contact

 JOINTS:

                                              Fig. Joints defined for the long piston 

MESH:

The mesh above is the combination of tetrahedron mesh and hexahedral mesh respectively and the critical contact areas where there is contact between barrel and cam with face sizing of 2mm respectively.

                                                       Fig. Mesh Generation

                                                          Fig.Element quality

                                                       Fig.Skewness of the mesh generated

BOUNDARY CONDITIONS:

                                                   Fig.Boundary Conditions

In he following figure above the Cam is made to rotate with an angle of 140 degrees respectively in 7 corresponding substeps basically.

SOLUTION:

CASE I:

                                    Fig.Total Deformation for CASEI

                                    Fig.Directional Deformation 

                                           Fig.VOn-Mises Stress for CASE I

                                   Fig. Equivalent Strain for CASE I

CASE II: FRICTIONAL COEFFICIENT OF 0.1 INDUCED BETWEEN THE CONTACTS

Since the Boundary Conditions and the mesh is going to remain the same in the following simulation therefore the direct simulatios results wi be discussed for the following 2 cases 

 SOLUTION CASE II:

                                                    Fig. Directional Deformation in X direction

                                                                 Fig. Von Mises Stress for CASE II

                                                         Fig.Equivalent Strain CASE II

SOLUTION CASE III: For Frictional Co-Efficient 0.2

                                                                Fig.Directional Deformation Case III

                                                         Fig.Von Mises Stress For Case III

                                                       Fig.Equivalent Strain CASE III

Sr No	Case	Directional Deformation in X dirn (mm)	Von mises stress(MPa)	Equivalent Strain
1	1	17.992	966.53	0.0048
2	2	17.924	430.43	0.0021
3	3	17.917	1367.5	0.0068

Conclusion: From the above table it is confirmed that the max deformation occurs in CASE I and max Correspnding stress occurs in CASE III having highest frictional resistance co-effecient