Week 1 Spur Gear Challenge
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(Learn about what stress intensity is). 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:
Case-1: Cast iron:
- cast iron is a group of iron_carbon alloys with a carbon content of more than 2% and considerable amount of silicon.also it contains smaller amount of sulphur,phosphorus and manganeese.
- cast iron is widely used for cast components which are not required to withstand impact or shock loads.it is having low melting temperature.
- this alloy affects its colour when it is fractured.
- white cast iron has carbide impurities which allows crack to pass through
- grey cast iron has graphite flakes which deflect a passing crack and intiate countless new cracks as the material breaks
- ductile cat iron has spherical graphite 'nodules' which stops the crack from furthe processing.
Material Assignment:
- Open Ansys
- Right click on Engineer Data
- Right click on geometry
- right click on model
- go to model
- Now assign the material
Connections:
contacts:
A frictional contact is defined between the tooth faces of the teeth in contact for both the gears with the behavior being set symmetric and "augment lagrange"is being set to reduce chatter and penetration.
- Go to connnections
- go to type as select frictional,behaviour as symmetric,formulation as augmented Lagrange,Interface treatment As Adjust to touch
joints:
Revolute joints are created for two gears for left gear give rotation in 6steps with 30 degrees each.and for right gear give moment 10N-mm for all steps
- Go to connections
- Go to connections
- now go to static structural
- Go to static structural
- same procedure for joint2 but we need to give moment -10N-M
- go to mesh
Out put Requests:
Total deformation:
It gives the out put for all directions for each node in the mesh generation data
Equivalent Stress:
The equivalent non directional stress values produced in the material of the gear are the energy of distortion/shear strain in the gears
Equivalent Elastic strain:
Stress intensity:
- stress intensity is a measure of the stress fields and distribution around developed crack and is a fundamental parameter which is used to study crack propagation leading up to failure.
- it meant to be localised stress distribution in the gear tooth which are in contact with each other.
CASE2:
CAST STEEL:
- cast steel is a ferrous alloy with a maximum carbon content of 0.75%.
- steel castings are solid metal objects produced by filling the void with in mold with liquid steel
- they are available in many of the same carbon and alloy steels that can be produced in wrought metals
Results:
Total Deformation:
elastic strain:
Equivalent Stress:
stress Intensity:
Case-3 :
CAST BRONZE :
Bronze is an alloy of copper and Tin .It is a hard and strong alloy with good corrosion resistance .it has a low value of coefficient of friction .it can be rolled in to sheets or cast into shapes.
RESULTS:
Total deformation:
Strain:
Stress:
STRESS INTENSITY:
RESULTS COMPARISSON:
| s.no | Properties | cast iron | cast steel | cast Bronze |
| 1. | Deformation(mm) | 30 | 30 | 30 |
|
2. |
stress(MPa) | 408.52 | 394.16 | 401.77 |
| 3. | strain | 0.0033589 | 0.0021742 | 0.0050483 |
| 4. | stress intensity(MPa) | 391.64 | 421.07 | 432.21 |
CONCLUSSION:
At the root of the tooth having maximum stress intensity the failure of gear will occur here it self.
From comparing Results cast iron having less stress intensity but in manufacturing point of view bronze and steel is more ductile than cast iron.so manufacturing with cast steel is good interms of manufacturing and strength poin of view