Week 1 Stress Concentration on a Plate with hole
Aim :
To create the geometry for the given dimensions and to determine the maximum deformation and stress developed in the model for two cases by using Ansys software.
Objective :
To compare the maximum deformation and stress developed between the two different cases and choose the case for analysis point and manufacturing point.
Theory :
Deformation occurs when the internal resistance is less than the applied load (stress).
Stress concentration occurs when there is irregularities in the geometry or material of structural component that cause an interruption to the flow of stress. This may also occur from accidental damage such as nicks and scratches.
When a body has stress concentration in it, the chances of its failure increases. The body tends to fail from the place where it has more concentration of stress. A body has less life that has more irregularities within it. In order to increase the life of the body, the intensity of stress should be reduced.
Stress concentration factor K = actual maximum stress / average stress.
Equivalent stress is widely used to represent a material's status for ductile material. Engineers use this simple scalar value to determine if the material has yield or failed.
| CASE | Equivalent stress | Total Deformation |
| 1 | Min : 8.4186e-003 Mpa, Max : 0.295 Mpa | Min : 0, Max : 1.37e-004 |
| 2 | Min : 4.382e-003 Mpa, Max : 0.5826 Mpa | Min : 0, Max : 2.9701e-004 |
from the above result it is clear that the max equalent stress and total deformation is higher in the cas two which is having a dimension of
length = 300 mm,
breadth = 120 mm,
width = 30 mm,
hole at center = 60 mm (dia),
hole at 90 mm away from both sides = 30 mm (dia),
whereas the case 1remails the same with only one hole at center 60 mm dia.
With respect to point of analysis i choose case 2. Because less no of elememnts = less chance of inaccuracy,
With respect to point of manufacturing i choose case 1. because it reduces time and cost to manufacture.
Result :
The creation of solid geometry as per given dimension and analysis of equalent stress and total deformation is completed successfully using ANSYS.