Week 7-Long Piston With Cam
Long Piston with Cam
Objective:
To perform a transient analysis on piston & cam mechanism for three different cases namely
Case 1: Frictionless Contact
Case 2: Frictional Coefficient of 0.1
Case 3: Frictional Coefficient of 0.2
& to compare the directional deformation, equivalent stress & equivalent strain for the above cases.
Geometry:
The above geometry consists of a barrel, cam follower & a barrel cam.
The barrel & the barrel cam are defined as rigid bodies as shown above.
Material:
Structural steel has been used as the material for all the components & its material data is shown above.
Joints:
Barrel is defined as fixed joint as shown above.
Barrel Cam is defined as a revolute joint as shown above.
Inner cylindrical surface of Cam Follower is defined as a translational join translating along x direction inside the barrel as shown above.
Mesh:
The mesh metrics is shown above.
A face sizing of 1mm is applied on the above highlighted surfaces.
Global Element Size: 2.5mm
No of Nodes: 25405
No of Elements: 10131
Boundary Conditions:
A joint rotational load is applied as shown above.
Analysis Settings:
The above analysis settings are used. Large deflection is turned on. Weak Springs are set to program controlled. Stabilization energy dissipation is set to 0.1. Contact Miscellaneous is set to yes in output controls.
Case 1: Frictionless Contact b/w the contact regions
Contacts:
Frictionless contact is defined b/w cam follower & the barrel as shown above.
Frictionless contact is defined b/w cam follower & the barrel cam as shown above.
Force Convergence & Time Increment:
Results:
The component undergoes a max directional deformation of 12.74mm & a minimum directional deformation of 10.103mm as shown above.
The component has a maximum equivalent elastic strain of 0.039046mm/mm as shown above.
The component has a maximum equivalent stress of 7779.4Mpa as shown above.
Case 2: Frictional Contact b/w the contact regions with a friction coefficient of 0.1
Contacts:
Frictionless contact is defined b/w cam follower & the barrel as shown above.
Frictionless contact is defined b/w cam follower & the barrel cam as shown above.
Force Convergence & Time Increment:
Results:
The component undergoes a max directional deformation of 12.843mm & a minimum directional deformation of 10.251mm as shown above.
The component has a maximum equivalent elastic strain of 0.040342mm/mm as shown above.
The component has a maximum equivalent stress of 8038.3Mpa as shown above.
Case 3: Frictional Contact b/w the contact regions with a friction coefficient of 0.2
Contacts:
Frictionless contact is defined b/w cam follower & the barrel as shown above.
Frictionless contact is defined b/w cam follower & the barrel cam as shown above.
Force Convergence & Time Increment:
Results:
The component undergoes a max directional deformation of 12.954mm & a minimum directional deformation of 10.407mm as shown above.
The component has a maximum equivalent elastic strain of 0.041768mm/mm as shown above.
The component has a maximum equivalent stress of 8322.6Mpa as shown above.
Comparison:
|
|
Maximum Directional Deformation (mm) |
Minimum Directional Deformation (mm) |
Maximum Equivalent Elastic Strain (mm/mm) |
Maximum Equivalent Stress |
|
Case 1 |
12.74 |
10.103 |
0.039046 |
7779.4 |
|
Case 2 |
12.843 |
10.251 |
0.040342 |
8038.3 |
|
Case 3 |
12.954 |
10.407 |
0.041768 |
8322.6 |
From the above comparison, Case 3 has the highest directional deformation, equivalent elastic strain & equivalent stress out of all 3 cases. Friction is the force resisting relative motion of substance sliding over each other. Hence, when u have a higher frictional coefficient, the resistance to motion is reduced & there will be more deformation. Thus, due to this deformation stresses & strain also increases.
Long Piston & Cam : https://drive.google.com/file/d/1Qw7qhvav5Zb5D-WEBP1eflZ_H0Ege0YT/view?usp=sharing