Week 8 Worm Gear Challenge

Objective: In this challenge, we are going to perform the transient structural analysis on the Worm Gear Assembly. We are trying to refine the mesh ( Keeping the node count below 34K) and analyze the Equivalent Stress, Equivalent Strain, and Total Deformation.

Case setup

•  After opening ANSYS Workbench, we are met with the Project Schematic window. Here, we can select the 'Transient Structural' analysis system on the left. Doing so creates a new project. Here, we can rename the project and also change the material if needed. We will need to right-click 'Geometry' and select 'import'. The file provided for this project should be selected.
• To create/edit new materias go to engineering data sources - general materials - select required materials.
• For this project we use only structural steel material.

Material properties of structural steel

• The 3D model of the setup is imported into ANSYS Space Claim. Check for any abnormalities in the Geometry.
• For analysis purpose, we have split the geometry. It reduceses the simulation time and keeping the node limit below acedemic version.

  

• After importing the Geometry, rename the components as Worm and Gear and assign structural steel for both components.

Connections:

Contacts:

Contact_1: Worm to Gear

Type: Frictionless

Contact Body = Worm

Target Body = Gear

Joints :

Joint_1

Connection Type: Ground to Gear

Type: Revolute

Body: Gear

Joint_2

Connection Type: Ground to Worm

Type: Revolute

Body: Worm

Mesh: We have deployed the mesh with a global element size of 2 mm and then we have given the face sizing of 1mm to all the faces which are coming into contact.

Boundary Conditions:

After meshing as described above, create Boundary Conditions as given below:

Analysis Settings: 

No.of Steps: 15
Solver Type: Program Controlled
Weak Springs: Program Controlled
Large Deflection: ON
Auto Time Stepping: ON
Defined By : Time
Initial Time Step: 2 s
Minimum Time Step: 0.2 s
Output Controls: Stress, Strain, Contact Data, Nodal Forces, Volume & Energy, Euler Angles, General Miscellaneous etc. to Yes

We have applied the Joint load of rotation to the Worm. Total Rotation of 750 degrees is applied in 15 steps.

• Run the simulation to generate eqivalent stress,eqivalent elastic strain and total defromation as solution outputs.

RESULTS

Total defromation

Eqivalent stress

Eqivalent elastic strain

Conclusion:

Transient Structural Analysis is successfully performed on the worm and gear assembly without an error and results are given below.

Total Deformation 7.2815 mm
Equivalent Stress 2505.6 MPa
Equivalent Strain 0.012952 mm/mm

MATERIALS for worm and worm gears are generally confined to steel for worms and bronze or cast iron for gears to minimize the stress and pressure and to reduce the loss of efficiency, but in this challenge we used only structural steel for both worm and gear so this is one of the reason for high stresses.

google link

https://drive.google.com/file/d/1QVev6ghOR3-N4TxbABhmn7U004QDuJme/view?usp=sharing