Week 1 Stress Concentration on a Plate with hole
1. Objective
To design a rectangular plate with circular hole as per the dimensions given in the two cases and compare the stress and deformation results. Also comment which of the two cases are suitable from analysis and manufacturing point of view.
2. Procedure
The design is prepared in Ansys Spaceclaim as per the dimensions given in two cases as it provides a greater flexibility in modeling as compared to Design Modeler. Then material assignment, meshing, application of boundary condition is done to solve the FE model for the required output. The von-Mises stress and total deformation is obtained as an output and then comparison of the results are done.
Fig 1. Spaceclaim Model - Case 1
Fig 2. Spaceclaim Model - Case 2
The material assigned for both the model is Structural Steel and a tetrahedron mesh size of 5 mm is considered for the analysis. The left face is fixed and a load of 500 N is applied on the right face.
Fig 3. Meshed Model - Case 1
Fig 4. Maximum von-Mises Stress - Case 1
Fig 5. Maximum Deformation - Case 1
Fig 6. Meshed Model - Case 2
Fig 7. Maximum von-Mises Stress - Case 2
Fig 8. Maximum Deformation - Case 2
3. Comparison of Results
The Finite Element Analysis shows that the maximum stress is 0.048 % less in Case 2 as compared to Case 1 whereas the total deformation in Case 2 is 8.086 % higher than Case 1. The deformation and maximum stress values are inversely proportional to each other.
Table 1. Result Comparison
| SL No | Values | Model 1 | Model 2 | % Change |
| 1 | von-Mises Stress (Mpa) | 0.61058 | 0.58098 | 0.048478496 |
| 2 | Total Deformation (mm) | 0.00027478 | 0.000297 | -8.086469175 |
4. Design Selection from Analysis Point of View
As the maximum von-Mises Stress in Case 2 with 3 holes is less and the stress distribution is also better it is recommended from analysis point of view.
5. Design Selection from Manufacturing Point of View
As the Model 2 contains holes of two different diameters, i.e 30 mm and 60 mm, two punch of different size has to be used to produce the holes. Thus the cost of tool and time required to prepare the model will be more in Case 2. From Manufacturing Point of view Case 1 is better and it has only one hole.