Static structural analysis on a plate with a hole geometry
Stress Concentration on a Plate with hole
Aim: To determine the stress & total deformation on a plate with a hole geometry
Case 1: Plate with a hole (increased thickness)
Model:
From the above fig, the length & width of the plate, the wall thickness of the hole & hole diameter can be observed. The plate shown above has a thickness of 30mm.
Material: Structural Steel is considered to be the material of the plate & its properties are shown in the below table.
Mesh Details:
From the above mesh metric graph, it can be observed that the element quality is above 0.2.
Minimum Element Size: 0.5mm
Proximity Element Size: 0.5mm
Maximum Face Size: 5mm
Maximum Tetrahedron Size: 10mm
No of Nodes: 68964
No of Elements: 45343
Boundary Conditions :
As seen in the above fig, the plate is fixed from one end & a load of 500N(tension) acts on the opposite end.
Results:
The plate experiences maximum stress of about 0.59 Mpa as shown above.
The plate experiences maximum deformation of about 0.27 microns as shown above.
Case 2: Plate with multiple holes
Model:
From the above fig, the length & width of the plate, the wall thickness of the holes & hole diameters can be observed. The plate shown above has a thickness of 30mm.
Material: Structural Steel is considered to be the material of the plate & its properties are shown in the below table.
Mesh Details:
From the above mesh metric graph, it can be observed that the element quality is above 0.2.
Minimum Element Size: 0.5mm
Proximity Element Size: 0.5mm
Maximum Face Size: 5mm
Maximum Tetrahedron Size: 10mm
No of Nodes: 68578
No of Elements: 44874
Boundary Conditions :
As seen in the above fig, the plate is fixed from one end & a load of 500N(tension) acts on the opposite end.
Results:
The plate experiences maximum stress of about 0.57 Mpa as shown above.
The plate experiences maximum deformation of about 0.29 microns as shown above.
Comparison:
|
Equivalent Von-Mises Stress (Mpa) |
Total Deformation (mm) |
|
|
Case 1 |
0.59 |
0.00027 |
|
Case 2 |
0.57 |
0.00029 |
From the above comparison, Case 2 has a slightly lower stress concentration when compared to case 1. On the contrary, Case 2 marginally has a higher deformation than Case 1.
From an analysis point of view, Case 2 has a longer fatigue life (If we check the S-N curve or evaluate for FOS ) than Case 1. Also due to the presence of smaller hole before the central larger hole, there is no sudden change of cross-section at the center and hence slightly lesser stress concentration.
From a manufacturing point of view, Case 1 needs less time to be manufactured & hence less cost as compared to Case 2.
Case 2 will be lighter in weight when compared to Case 1.
Finally, depending on the application we need to choose whether we have to look at deformation or stress acting on a member.