Grid dependency test on Bevel Gears
Grid Dependency Test, In which one can know ,the performed mesh size is good for analysis?
It is well known that finer the mesh size ,results in high accuracy but at the cost of computational time,memory. Grid dependency is refining the mesh from coarser to finer, in few steps, in which the results doesnt change significantly at some point compared to earlier steps ,and finding the optimum mesh size based on the results.
Grid Dependency test on Bevel Gears:
Aim:
To perform a grid dependency test for the Bevel gear simulation for mesh sizes of 6,5 and 4 mm and to obtain results for Von-Mises stress, Equivalent elastic strain and Total Deformation using the different mesh sizes.
Setup:
The model is loaded in Space claim and removed the unwanted region for simulation, as it increases the number of Nodes/elements and time,memory.
and corresponding contacts/targets were selected.
The small gear is for contact and big gear is target. the contact type is frictional,behaviour is symmetric, formulation to augmented lagarange.
Then the joints are created, ie revolute and corresponding rotation axis direction is changed.
Also the meshing is done with 5 mm and the face sizing is done with 1.75mm.
Then the analysis setting is made to rotate the gear in 6 steps for the angle of 120Deg.
Number of Steps: 6
Auto Timing Step:on
Intial time step: 0.1s
Min time step: 5e-2
Max Time step:0.2
Then the joint load is applied by creating the rotation and moment as follows in 6 steps.
The results are as follows,
Total Deformation:
Elastic Strain:
Elastic Stress
Through parametric tool,adding mesh of different sizes,
Results of varying mesh size:
Upon comparing the results of different mesh sizes,the Total deformation is same for all three meshes.
in elastic strain, between 6 and 5 mm the difference is negligble. between 5mm and 4 mm the difference is around 12%.
in elastic stress, between 6 and 5 mm the difference is 8%. between 5mm and 4 mm the difference is also around 8%.
Changing the mesh from 5mm to 4 mm results in change , comparing the these three meshes it is advised to use the mesh of 4mm., as the finer mesh would produce accurate results.