Grid Dependency Test on Bevel Gear (ANSYS WorkBench)

Aim :

Perform a Grid Dependency test for Bvel gear simulation for mesh sizes of 4mm ,5mm and 6mm. Also solve for Von-Mises Stress, Equivalent Elastic Strain and Total Deformation using the three mesh sizes.

FILE : Bevel_Gear

Grid Dependency test :

Grid dependency test is to investigate how the solution depends on the grid size by running the simulation with refined mesh that is finer the mesh, higher is the accuracy of the result but with additional cost on computation time and computational power. Since, solutions are interpolated at the nodes to get an approximate result, higher the number of nodes and elements higher is the computational time and power required to complete the simulation.

So, the grid dependency test helps in determining optimal mesh size where the accurate result could be obtained keeping in the mind the cost of time and power. Since the result obtained are approximate, Refining mesh further would result in negligible per cent change is the result but only increase the computational cost.

Procedure :

1. Import the geometry and open the Model Setting.
   
   
   The gears renamed to Small_Gear and Big_Gear with Structured Steel as there material.
   
   
2. Frictional Connection was given by manually selecting the Target Faces and Contact Faces with rest of the settings as default.
   
   
   
   
3. For meshing process
   
   Element size of 4mm was given and Face Sizing was with element size of 1.75mm was given to the contact surfaces.
   
   
   
   Face Sizing :
   
   
   
4. In the connection settings the gears where given with revolute joint with there axis specified correctly in the direction of rotations.
   
   
   
   
   
   
5. In the Static Structural Settings a moment was given to the Big gear and rotation was given accordingly. The moment was given for a time step of 6 which was set in the Analysis Settings.
   
   
   
   
   
   
   

Result :

Total Deformation :

Equivalent Stress :

Equivalent Strain :

Grid Dependency Test :

Design Points	Mesh Element Size [mm]	Total Deformation Min [mm]	Total Deformation Maximum [mm]	Eq. Stress Min [MPa]	Eq. Stress Max [Mpa]	Eq Elastic Strain Min	Eq Elastic Strain max
DP 0	4	21.65063413	47.87277393	2.25E-08	4.840653649	1.13E-13	3.15E-05
DP 1	5	21.65063415	47.87278128	1.99E-08	5.602424607	1.75E-13	3.61E-05
DP 2	6	21.65063407	47.87277716	2.32E-08	3.577344536	1.22E-13	2.35E-05

Conclusion :

Grid Dependency test has been performed and From the above table, we can conclude performing grid dependency test on bevel gear by varying the global size of the mesh we achieve much better accuracy of the result. We can observe that as the mesh is refined from e.g 5mm to 4mm we achieve better approximate of the result for equivalent elastic strain and equivalent stress, however, performing the simulation with further refining the mesh would result in a very close approximation of the result but with very negligible change in the result with an additional on the computational power and time.