Week 8 - Universal Joint
Objective:
To perform transient structural analysis on a double universal joint with a spring using three different materials: Structural steel, Stainless stell and Titanium alloy which will only be assigned to the joint on the spring. To obtain equivalent stress and total deformation for all cases and compare them.
Setup:
For case 2 and case 3 we add materials Stainless Steel and Titanium alloy from General Materials respectively. After that we import the geometry and load it in spaceclaim to check for any abnormalities. After that we load the mechanical module. Once opened rename the parts as Spring, Gear, Ball joint, Ball joint and Shaft respectively. We assign the materials to the spring. Once that is done then we delete the default contacts and then we add body to ground fixed joint by selecting the surface of the spring. Then we give a ground to body revolute contact for both gear and spring. After that we give a body to body revolute contact with all eight points with ball joints in which the reference contact body is the surface in the ball joints and the mobile contact body is the cylindrical surface on the gear spring and the shaft. After all the eight points are defined as body to body revolute joint. Then we go to the mesh and give a mesh size of 4mm and switching adaptive sizing to no. Then going to analysis settings we give 5 steps. Selecting all the five steps switch off the suto time stepping and give the time step value as 0.1 then all output controls are changed to yes. After that is done a joint load is given for Ground to body joint for Ground to Gear joint. We give rotational values and in tabular column which are 30,60,90,120 and 150. Then we add solutions we need which are Equivalent stress and Total deformation.
Structural steel:
Total Deformation:
The maximum deformation is 38.637 mm which occured at the gear tooth.
Equivalent Stress:
The maximum amount of stress developed is 8071.4 MPa
Stainless Steel:
Total Deformation:
The maximum amount of deformation is 38.637 mm which occured at the tooth of the gear.
Equivalent Stress:
The maximum amount of stress developed is 1449.4 MPa which occurs at the spring.
Titanium Alloy:
Total Deformation:
The maximum amount of total deformation is 38.637mm which occured at the tooth of the gear.
Equivalent Stress:
The maximum amount of equivalent stress developed was734.23 MPa which was at the spring.
Conclusion:
| Total Deformation (mm) | Equivalent Stress (MPa) | |
| Strucutal Steel | 38.637 | 8071.4 |
| Stainless Steel | 38.637 | 1449.4 |
| Titanium Alloy | 38.637 | 734.23 |
The total deformation remained same for all cases. The Maximum amount of Equivalent Stress is developed by Structural steel at 8071.4 MPa followed by Stainless Steel at 1449.4 MPa and last by Titanium Alloy at 734.23 MPa. For both titanium alloy and stainless steel the maximum stress was developed at spring whereas for structural steel it occured at the joint. The total deformation also remained at the same locations.