Week 1 Stress Concentration on a Plate with hole

Objective:

To compare two designs for static loading.

1. Plate with a hole of diameter 60mm at the middle.

2. Plate with a hole of diameter 60mm at the middle and two holes of diamter 30mm to the either side of the middle hole.

Model Information:

Case 1:

Length=300mm

Height=120mm

Thickness=30mm

Circular Hole at the center:

Diameter=60mm

Case 2:

Length=300mm

Height=120mm

Thickness=30mm

Circular Hole at the center:

Diameter=60mm

Smaller hole 90mm away from the centre:

Diameter=30mm

Boundary Conditions:

1. Plate fixed at left face

2. 500N load at right face (-Z direction)

Case 1 Case 2

FE Information:

1. The model is discretized with TETRA mesh of 2mm average length.

2. Structural Steel material is assigned to the model in both cases.

Results:

Comparison of Total Deformation and Equivalent Stress:

Model	Total Deformation (mm)	Equivalent (von-mises) Stress (MPa)
Case 1	0.00027492	0.60544
Case 2	0.00029728	0.58166

Case 1: Total Deformation

Case 2: Total Deformation

:

Case 1: Equivalent Stress

Case 2: Equivalent Stress

Conclusions:

1. Case 1 model has higher stress compared to Case 2 model. However, Case 2 model has higher deformation compared to Case 1 model.

2. From Analysis standpoint, Case 2 model is better as the stresses developed in the model after loading is lesser compared to case 1 model. Also, additonal holes will bring weight reduction.

3. From Manufacturing standpoint, Case 1 model is preferred as the creation of additional holes will be expensive.