Stress Concentration on a plate with hole

Objective: Static Structural analysis on a plate with a single hole and a plate with multiple holes.

Question:

CASE-1:

Model: A plate is modelled as shown in question.

Boundary Conditions:

Material: Structural steel

Mesh Size: 3.5mm

Type of Elements: Tetrahedron

Fixed Support: Left surface as shown in question.

Force(Tensile): 500N on the right surface in +ve X-axis direction.

Gravity: -ve Z-axis direction.

Results:

Von-mises stress plot:

Deformation Plot:

CASE-2:

Model: A plate is modelled as shown in question.

Boundary Conditions:

Material: Structural steel

Mesh Size: 3.5mm

Type of Elements: Tetrahedron

Fixed Support: Left surface as shown in question.

Force(Tensile): 500N on the right surface in +ve X-axis direction.

Gravity: -ve Z-axis direction.

Results:

Von-mises stress plot:

Deformation Plot:

Comparison & Conclusion:

CASE	Equivalent Stress(Mpa)		Total Deformation(mm)
	Max	Min	Max	Min
1	0.66309	0.0003635	0.00053929	0
2	0.63753	0.00088126	0.00054041	0

• The stress developed in CASE-1 is more than in CASE-2, this is so because the stress developed in the multiple holes plate gets distributed due to the presence of smaller holes in the same plate, while there is only a single hole in CASE-1 and total deformation is slightly higher in Case-2 as stress is distributed along the body, strain is increased which resulted in increase in deformation.
• From an analysis standpoint, I will select the 2nd design as there is uniform stress distribution due to the presence of multiple holes and the deformation as compared to CASE-1 is slightly higher and negligible.
• From a manufacturing standpoint, CASE-1 will be preferred since it involves producing only a single hole of 60mm diameter and hence saves on the machining cost and effort as compared to CASE-2 where two additional 30mm diameter holes are to produced.