Week 1 Spur Gear Challenge

Aim : To perform static structural analysis on spur gear to find out equivalent stress, total deformation and stress intensity.

Objectives :

• Objective 1 :
  • Case 1: Using Cast Iron(ductile) as a material, carry out a static structural analysis to find out Equivalent stress, Total deformation and Stress intensity. Find location for possible fracture.
  • Case 2: Using Cast Steel as material, perform the same analysis for the results as in Case 1.
  • Case 3: Using Cast Bronze as material, perform the same analysis for the results as in Case 1.

• Objective 2 : Write a detailed report comparing the results of the three cases and conclude which material would you recommend based on these results.

Procedure :

Create materials and assign :

• Open ansys workbench and set the case of structural analysis on workbench UI.
• Now click on engineering data and it will open material window from there select ANSYS GRANTA materials and choose cast iron predefined material quality.
• For second material create a second case by duplicating first case the from engineering data change the material. Duplicate for case-2.
• Click on Engineering data in second case and then a new window will pop-up now from the engineering data sources we can select any predefined material or we can create a seperate material.
• For that click on "click here to add a new material" and rename as cast steel and set all quality for that material as given for the challenge.
• Set all material quality as given for this model.

Geometry :

• Import cad file in Geometry and open it in space claim.
• To check weather cad model is fine or not,if any error will found then fix it.

Model :

• Check the geometry details and assign material from there as required.
• Define contacts by selecting teeth contacting surface.

• Joints :

For Right Gear

For Left Gear

Meshing :

• Give element size of 0.5 mm.
• Generate mesh.

Analysis Setting :

Joint Load :

For Right Gear

For Left Gear

Solution :

• We will create output results for total deformation, equivalent stress, equivalent strain and stress intensity.
• Click on Solve.

Results :

A) Objective 1 :

Case 1 : Using Cast Iron as a material.

Total Deformation :

Equivalent Stress :

Equivalent Strain :

Stress Intensity :

Case 2 : Using Cast Steel as a material.

Total Deformation :

Equivalent Stress :

Equivalent Strain :

Stress Intensity :

Case 3 : Using Cast Bronze as a material.

Total Deformation :

Equivalent Stress :

Equivalent Strain :

Stress Intensity :

Objective 2 : Comparing the results of the three cases.

Sr.No.	Results	Cast Iron	Cast Steel	Cast Bronze
1	Total deformation Maximum (mm)	30	30	30
2	Total deformation Minimum (mm)	18.5	18.5	18.5
3	Equivalent Stress Maximum (Mpa)	470.85	462.73	444.56
4	Equivalent Stress Minimum (Mpa)	3.3014 E-6	1.0041 E-5	6.3312 E-6
5	Stress Intensity Maximum (Mpa)	533.12	521.68	497.96
6	Stress Intensity Minimum (Mpa)	3.7951 E-6	1.0932 E-5	7.2917 E-6

Conclusion :

• For all three materials, the maximum stress was observed in the root of the teeth. Similarly, the stress intensity measured was also found to be maximum in the same region.

• The deformation is however found to be similar for all the cases.

• Equivalent Stress : Cast Iron > Cast Steel > Cast Bronze.

• Stress Intensity : Cast Iron > Cast Steel > Cast Bronze.

• From the results, it is observed that the equivalent stress and the stress intensity is maximum for cast iron and minimum for the cast bronze.
• The smaller values of stress intensity assist the part in achieving a longer life.
• Hence, from the analysis, it can be considered that cast bronze is the a typical material for the spur gears due to the lower values of equivalent stress and stress intensity experienced by the material for the same boundary conditions.