Week 2 Bevel Gear Challenge

Aim : To perform static structural analysis on Bevel gear.

Objectives :

• Perform a grid dependency test for the Bevel gear simulation for mesh sizes of 6, 5 and 4 mm.

• Solve for Von-Mises stress, Equivalent elastic strain and Total Deformation using the previously mentioned mesh sizes.

Grid dependency test :

In grid dependency test, where, analysis begins with a coarse mesh and it is refined to finer mesh for each run until the results do not change significantly and depend on the grid size. i.e. mesh is the significant parameter to produce accurate results higher the density of mesh higher the accuracy of the solution but it will consume a lot of computational time, hence this test is used to find the mesh size that gives us an appropriate result to the accurate result. Initially, it will start with a coarse mesh to a finer mesh.

Procedure :

Static structural and Engineering data :

• Open Ansys workbench and select static structural type of analysis.
• Then go settings of engineering data to select appropriate material,in this case choose structural steel as a material.

Geometry :

• Import the geometry.
• Remove uneccessary material by drawing circle as dedendum circle.
• Use pull option to remove material.

Model Setup :

• Contacts :

• Joints :

For Big Gear

For Small Gear

• Meshing :

As we are performing grid dependency test for mesh sizes of 6, 5 and 4 mm.

We will set this mesh size as a Input parameter.

Give Face sizing of 1.75 mm by selecting faces of teeth of both gear.

• Analysis Setting :

• Joint load :

For Big Gear

For Small Gear

• Solution :

Create output results for Von-Mises stress, Equivalent elastic strain and Total Deformation.

Solve the model.

Results :

Case 1 : For mesh size 6 mm.

Total deformation :

Equivalent stress :

Equivalent strain :

Case 2 : For mesh size 5 mm.

Total deformation :

Equivalent stress :

Equivalent strain :

Case 3 : For mesh size 4 mm.

Total deformation :

Equivalent stress :

Equivalent strain :

Parametric study :

Grid Dependency Test :

• We perform grid depency in simulation is basically to get appropriate results.
• In grid dependy we do perform simulation on different mesh size and evaluate simulation results.
• If result is seen approx same for two last successive mesh size then we accept that mesh size for final as result.

Sr.No	Results	Case 1	Case 2	Case 3
1	Total deformation Minimum (mm)	21.6506	21.6506	21.6506
2	Total deformation Maximum (mm)	47.873	47.873	47.873
3	Equivalent Stress Minimum (Mpa)	6.4052 E-08	5.8605 E-08	6.4001 E-08
4	Equivalent Stress Maximum (Mpa)	3.5961	3.9770	4.0866
5	Equivalent Strain Minimum	3.5120 E-13	3.4563 E-13	3.6328 E-13
6	Equivalent Strain Maximum	2.0205 E-05	2.7292 E-05	2.7739 E-05

Conclusion :

• From above table we can see that the total deformation value is same in all case. But stress and strain values are close for a case 1 and case 3.

• Comparing the results for total deformation, equivalent stress and equivalent elastic strain it is observed that as the mesh size decreased we get more accurate results.

• A finer mesh is generated resulting in a higher number of elements thereby providing accurate results.