Week 2 Bevel Gear Challenge

Finite element analysis most basic principle is meshing. The accuracy of FTA analysis depends on the type of meshing is generated in the element. This means that finer the mesh quality, higher will be the accuracy of the result. But it will also increase the computational time and hence increasing the computational cost of the analysis. Hence to maneuver such situations grid dependency test has been introduced in FEA.

Grid dependency test can be defined as a process to figure out minimum mesh element size after which the accuracy of the result does not vary.

Following is the process to conduct grade dependency test:

Step 1: Run the analysis using default mesh size.

Step 2: Now reduce the mesh element size by 20 to 30% of its default size and run the analysis again

Step 3: Repeat step 2 until you reach a point where the mesh element size does not change the analysis result.

In this challenge a grade dependency test has been conducted on a pair of bevel gears.

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

Analysis Parameter:-

• Tow bevel gears in Frictional Contact with eachother.
• Moment of 100 N-mm is applied to Big Gear and the system is rotated upto 120 degrees.
• Stress, Strain & Deformation of the Gears is recorded.
• This test is done for 4 different Mesh Sizes i.e. 6, 5, 4 & 3.

Analysis Result:-

• ANSYS parameter setting is used to generate desirde results and are shown below.

Conclution:-

• From the above analysis it is cleared that reducing the mesh size from 6 mm to 5 mm there is a considerable change in the amount of stress and strain results generated by the solver.
• But by further reducing the mesh size from 5 mm to 4 mm and to 3 mm the change in result is not significant.
• Thus there is no need to reduce the size of mesh below 4 mm, it will only result in increase of computational cost.