Static Structural analysis of Spur gear using Ansys

Objective - Static Structural analysis of Spur gear to find out the Equivalent stress, Total deformation and Stress intensity by using below listed materials.

• Cast Iron(ductile)
• Cast Steel
• Cast Bronze

Compare the results obtained by using 3 different materials for gears and Find location for possible fracture.

Procedure - Static structural analysis is carried out on Spur Gear by using Ansys Workbench.

• Create Static structural analysis and in engineering data select the material Cast Iron(ductile), Cast Steel and Cast Bronze.
• Import the geometry and check in SpaceClaim for any irregularities.

• Then open Ansys mechanical and rename the gears and assign the material according to the cases.

• Contacts - contacts created between the both spur gears. The contact type is frictional with the mating surface of gears selected as Contact and Target. The Behaviour is changed to symmetric and the Formulation type used is Augmented Lagrange. The interface treatment is set to Adjust to Touch.

• Joints - Joint set for both the gears as the Revolute and Body-Ground.

• Mesh - The gear is meshed with the size of 0.5mm. A mesh metric that identifies the element according to their quality.

• Analysis Settings - The simulation runs for 6 steps. So, the number of steps is set as 6, Define by time and large deflection is set to on.

• Joint Load - One of the gears is given rotation for six time steps and the other is given a constant moment.

• Joint Load Rotation.

• Joint Load Moment.

Now for different materials mentioned below the is selsted one by one and run the simulation to find out the Equivalent stress, Total deformation and Stress intensity.

• Case 1 Cast Iron(ductile)
• Case 2 Cast Steel
• Case 3 Cast Bronze

Case 1 Cast Iron(ductile)

Material Data

Equivalent Stress Max - 466.09 Mpa

Total Deformation Max - 30 mm

Stress Intensity Max - 525.12 Mpa

Location for possible fracture

Equivalent Stress - Animation

Case 2 Cast Steel

Material Data

Equivalent Stress Max - 460.21 Mpa

Total Deformation Max - 30 mm

Stress Intensity Max - 516.79 Mpa

Location for possible fracture

Equivalent Stress - Animation

Case 3 Cast Bronze

Material Data

Equivalent Stress Max - 442.83 Mpa

Total Deformation Max - 30 mm

Stress Intensity Max - 493.73 Mpa

Location for possible fracture

Equivalent Stress - Animation

Result and Conclusion - The analysis runs successfully and results obtained for all the cases.

• From the above comparison, Cast Bronze shows less impact compared to others.
• Equivalent stress & stress intensity of Cast Steel is slightly below as compared to Cast Iron, the ultimate strength of Cast Iron is higher than Cast Steel & hence will run for a few more cycles. So that life will be good and also the cost of the material is less compared to remaining and every material having their own advantages, so based on customer requirement, depending on the application and budget we can choose material.
• Crack is most likely to occur near at the root of the tooth.
• Deformation for all three materials is the same.

Google drive link - https://drive.google.com/open?id=18IEa2rF3Kg0UOTP5TmzF2fEjZS76bbnL