Long Piston With Cam
For the project using a long piston with cam, the material used is Structural Steel. This material is chosen from engineering data using engineering data sources. The details of this material are given below.
The geometry is imported into the mechanical DUI. It is opened in Space Claim DUI to check for anomalies. Once checked it is closed.
The model is opened in Mechanical DUI to carry out the mentioned objectives. The details of the geometry are mentioned below.
The parts were renamed as Barrel, Barrel Cam, Cam Follower respectively. The materials of all these parts were kept as structural steel. The Barrel and the Barrel Cam were kept as rigid bodies.
Barrel
Barrel Cam
Cam Follower
Rigid Bodies
Following this, the connections in the model were specified and necessary changes were made. The connections were made between the Cam Follower and the Barrel, and between the Cam Follower and the Barrel Cam. The connections were kept as frictionless.
From the connections, three different joints were also specified. The joints were fixed from ground to barrel, revolute from ground to barrel cam, and translational from barrel to cam follower. The details of these joints are mentioned below.
Joint 1 - Fixed joint - Ground to Barrel
Joint 2 - Revolute Joint - Ground to Barrel Cam
Joint 3 - Translational - Barrel to Cam Follower
Following this, a mesh was inserted. The mesh used was a default with minimum changes.It was coarse but no further modifications were made.
The details of the mesh are mentioned below.
Face Sizing
The analysis settings were changed. The initial settings were not changed as the working of the given module began from rest.
The details of the analysis settings are shown below.
A joint load was specified for the revolute joint between ground to barrel cam. The joint load was specified to be for rotation and the degrees of rotation was specified using a tabular data. The specifications of the joint load are mentioned below.
CASE 1
For the first objective, the connections were kept frictionless. The details of these changes are mentioned below.
Contact 1 - Cam Follower to Barrel
Contact 2 - Cam Follower to Barrel Cam
For the solution the conditions were specified. The conditions were equivalent elastic strain on the cam follower, equivalent stress on the cam follower, total deformation, directional acceleration, directional velocity on the barrel . A contact tool was also inserted to obtain values of the pressure in the contact regions. The maximum and minimum values including the details of these conditions are mentioned below.
|
Conditions |
Minimum Value |
Maximum Value |
|
Total deformation |
0 |
35.921mm |
|
Equivalent stress on the cam follower |
0.17663MPa |
1700.3MPa |
|
Equivalent elastic strain on the cam follower |
4.088e-6mm/mm |
0.0085321mm/mm |
|
Directional acceleration |
-2.9325mm/s^2 |
2.8774e-11mm/s^2 |
|
Directional velocity on the barrel |
-8.492e-28mm/s |
4.246e-28mm/s |
Total deformation
Equivalent stress on the cam follower
Equivalent elastic strain on the cam follower
Directional acceleration
Directional velocity on the barrel
Contact Tool
|
Conditions |
Minimum Value |
Maximum Value |
|
Pressure |
0 |
933.74MPa |
Status
Pressure
CASE 2
For this case, all the contact points were kept as frictional and the frictional coefficient was kept as 0.1. The details of these changes are mentioned below.
Contact 1
Contact 2
For the solution the conditions were specified. The conditions were equivalent elastic strain on the cam follower, equivalent stress on the cam follower, total deformation, directional acceleration, directional velocity on the barrel . A contact tool was also inserted to obtain values of the pressure in the contact regions. The maximum and minimum values including the details of these conditions are mentioned below.
|
Conditions |
Minimum Value |
Maximum Value |
|
Total deformation |
0 |
35.921mm |
|
Equivalent stress on the cam follower |
0.17783MPa |
1690.7MPa |
|
Equivalent elastic strain on the cam follower |
4.0813e-6mm/mm |
0.0084848mm/mm |
|
Directional acceleration |
-5.9234mm/s^2 |
1.9639e-26mm/s^2 |
|
Directional velocity on the barrel |
-8.492e-28mm/s |
4.246e-28mm/s |
Total deformation
Equivalent stress on the cam follower
Equivalent elastic strain on the cam follower
Directional acceleration
Directional velocity on the barrel
Contact Tool
|
Conditions |
Minimum Value |
Maximum Value |
|
Pressure |
0 |
902.12MPa |
Status
Pressure
CASE 3
For this case the contact points were left at frictional and the frictional coefficient was kept at 0.2. The details of these changes are mentioned below.
Contact 1
Contact 2
For the solution the conditions were specified. The conditions were equivalent elastic strain on the cam follower, equivalent stress on the cam follower, total deformation, directional acceleration, directional velocity on the barrel . A contact tool was also inserted to obtain values of the pressure in the contact regions. The maximum and minimum values including the details of these conditions are mentioned below.
|
Conditions |
Minimum Value |
Maximum Value |
|
Total deformation |
0 |
35.921mm |
|
Equivalent stress on the cam follower |
0.17859MPa |
1701.1MPa |
|
Equivalent elastic strain on the cam follower |
4.0755e-6mm/mm |
0.0085387mm/mm |
|
Directional acceleration |
-0.22198mm/s^2 |
3.8094mm/s^2 |
|
Directional velocity on the barrel |
-8.492e-28mm/s |
4.246e-28mm/s |
Total deformation
Equivalent stress on the cam follower
Equivalent elastic strain on the cam follower
Directional acceleration
Directional velocity on the barrel
Contact Tool
|
Conditions |
Minimum Value |
Maximum Value |
|
Pressure |
0 |
1040.8MPa |
Status
Pressure
COMPARISON
Total Deformation for all the above cases are equal the maximum value being 35.921mm. The equivalent elastic strain is nearly the same with a minor difference of 0.0003 or 0.0004mm/mm. In case of the equivalent stress, the maximum value is seen when the frictional coefficient is 0.2. The value comes to 1701.12MPa. The minimum value for the equivalent stress is seen in the case where the frictional coefficient is 0.1, the value being 1690MPa. When the directional acceleration is considered, the maximum value is seen in when the frictional coefficient is 0.2 and the minimum value is seen when the frictional coefficient is 0.1. In case of the directional velocity, the values are nearly the same in each of the three cases.