Week 1 Spur Gear Challenge

1. OBJECTIVE :

The main objective of this project is to investigate the strress,axial deformation, stress inttensity on the spur gears in mesh with each other.while investigating these factors the gears materials are changed.The material used is cast iron,cast bronze,cast steel.All the parameters mentioned above are analysed for all the materials.Then the stresses are compared with the manual calculation of stresses obtained theoritically.

2.  CASE SETUP & EXCECUTIONa.Geometry:  The geometry of two spur gears meshing with each other is imported in the structural analysis module of ansys                                                                                                                b.Materials : Once the geometry is inserted the materials has to be added & assigned to the geometry. In this case, there are three materials are involved viz. Cast iron, Cast                                                                   Bronze & Cast steel. Each of the materials are individually assigned for the results. Some materials are added to the library like cast steel its density and strength,                                           c. Model: Once the geometry is assigned and named then next step is meshing.so initially the automatic meshes are generated and if it is too coarse and the number of elements                                                        are less then we go for the sizing option in meshing. The size of the mesh is kept as 1mm in this case.
3. .
5. Joints : Here the joint defined for the geometry is revolute one because the gear rotates about a fixed point for both the gears which is the true nature of an gear.
6. Contacts : In total there are 13 teeth per gear. So for one single gear there are 26 faces in contact i.e two sides in one gear tooth.

                           Joints                                                                              Contacts                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Motion : One of the gear is given a rotation from 0 to 180 degree & the other gear is given a moment of 10000 N-mm.

         Solution: The designed model is analysed for max von misses stress, max deformation, stress intensity, minimum life cycle. The results are obtained for all the mentioned parameters.

3.CASE-1 : Gray cast iron

Max stress = 357 MPa

 

 

Max deformation= 30 mm

Stress Intensity= 575 MPa

4. CASE-2 : CAST STEEL GEAR

MAX STRESS = 368 MPa

MAX DEFORMATION= 30 mm

STRESS INTENSITY= 731.75 MPa

5.CASE-3 : CAST BRONZE GEAR :

MAX STRESS= 355 MPa

MAX STRESS INTENSITY= 398 MPa

MAX DEFORMATION = 30 mm

C

COMPARISON REPORT

	MATERIAL	MAX DEFORMATION	MAX STREESS	STRESS INTENSITY	YEILD STRENGTH
1	CAST BRONZE	30 mm	355 mpa	378 mpa	144 Mpa
2	CAST STEEL	30 mm	367 mpa	388 mpa	349 Mpa
3	CAST IRON	30 mm	360 mpa	378 mpa	420 Mpa

CONCLUSION:

Out of all the three materials cast iron has highest yield strength and the coparative stresses and stress intensity is also low. As a design engineer I would go for cast iron.

CALCULATION- BY LEWIS STRESS EQUATION