Week 1 Spur Gear Challenge
OBJECTIVE:
To simulate static structural analysis on spur gear with three different materials (cast iron(ductile), cast steel, and cast bronze) and compare their Total deformation, Equivalent stress(von Mises), Stress Intensity and find the location of the fracture and Compare the result of all three cases.
Different Cases For Analysis are as given below
CASE 1: CAST IRON.
CASE 2: BRONZE.
CASE 3: CAST STEEL.
Stress Intensity:
- Stress Intensity Factor (K) is used in the field of fracture mechanics. It predicts stress intensity near the tip of a crack caused by a remote load or residual stresses.
- The magnitude of K depends on:
- Sample
- Size and location of the crack
- Magnitude of load
- Distribution of load on the material
- Stress Intensity Factor is measured by knowing the loading conditions and the crack size.
(Fig. Stress Intensity Factor (K))
Stress Intensity Factor (K) = uniform stress (σ</>">σσ) * </>">√(π</>">ππ* a)
Where, a = length of the crack.
Assuming the crack as an ellipse, semi minor axis = 0, and thus consider only a.
STEPS FOR PERFORMING ANALYSIS:
1. Open ANSYS workbench.
2. Select the static structural module.
3. Select the proper Engineering data card.
4. Import geometry.
5. Open Mechanical model.
6. Give proper connections (contacts and joints).
7. Generate mesh.
8. Set Analysis Setting as given.
9. Insert output request
10. Analyze Result.
GEOMETRY
Import given model in ANSYS Workbench for static structural analysis. The spur gear has 13 teeth with driver gear being named as right gear and driver gear being named as left gear.
Add material for all cases :-
1) Bronze
2) Cast Iron :-
3) Cast steel
SET CONNECTION :-
SET REVOLUTE JOINTS :-
Meshed Model With 3 mm Mesh :-
Now let's define the Boundary condition.
- Here we are going to look at contact faces and stress developed for 1 revolution of spur gear. So for 180-degree angle, In the Analysis setting as shown in the figure.
- Select all the steps Before defining step tine and select "Large Deflection = ON" in solver controls.
- Other boundary Conditions for joints are given below
Joint Load:
- Joint: Revolute-Ground to left
- Type: Rotation
- Magnitude: Tabular Data
Tabular Data:
- Joint: Revolute-Ground to Right
- Type: Moment
- Magnitude: Tabular Data
Tabular Data:-
Solution :-
Cast Iron :-
1) Total Deformation :-
2. Equivalent Von-misses Stress:-
3) Stress Intensity :-
Cast Steel :-
1) Total Deformation :-
2. Equivalent Von-misses Stress:-
3) Stress Intensity :-
Case 3 :-
Bronze :-
1) Total Deformation :-
2) Equivalent Von-misses Stress:-
3) Stress Intensity :-
Comparison of Result:
| CASE | Max. Total Deformation (mm) |
Max. Equivalent Stress (von-misses) (MPa) |
Max. Stress Intensity (MPa) |
|
CASE_1(Gray Cast Iron) |
30 | 1073 | 1210 |
|
CASE_2(Cast Steel) |
30 | 1319 | 1488 |
|
CASE_3(Bronze) |
30 | 985 | 1116 |
RECOMMENDATION:
So, From the above analysis, We can choose the Material: Bronze for the Spur Gears