Week 1 Stress Concentration on a Plate with hole

Case :1

Design a plate with a hole model similar to what we worked in the class, but with increased thickness.
Determine the maximum deformation and stress developed in the model.

Plate dimensions:

Length=300mm
Height=120mm
Thickness=30mm
Circular Hole at the center:
Diameter=60mm

Case 2:

smaller holes 90mm away from the center:

Diameter=30mm
Boundary Conditions:
Plate fixed at left face.
Load of 500N on the right face.

output:

Compare the deformation and maximum stress developed on a structural steel model for the 2 cases
From an analysis standpoint, which of the design will you select?
From a manufacturing standpoint, which of the design will you select
Explanation :

First open the ansys workbench, then choose the static structural.

step-1 : Material assignment

• Open the engineering material and select the required material
• Structural steel is a default material

.
step-2 : geometry

• Open the spaceclaim from the static structural.
• Creade the 2D geomatry using spaceclaim.
• After finishing geomatry select pull option assign the thickness.

step-3 : Mesh

• Select the mesh in the window
• Elemet size is the 6mm
• Mesh --> Generate mesh

step-4 : Bountry condition

• Static structural --> right click, inset -->
• fixed supportchoose the left side, now the left side is the fixed
• Static structural --> right click, inset -->
• force choose the right side, 500N act on the right side
  

step-4 : Solution

• Extract deformation, Equivalent stress and Equivalent strain

TOTAL DEFORMATION

case maximum minimum

1 0.000274 0

2 0.000279 0

EQUIVALENT STRAIN

case maximum minimum

1 3.0044e-6 9.559e-8

2 2.8881e-6 2.3103e-8

EQUIVALENT STREES

case maximum minimum

1 0.06008 0.001908

2 0.05776 0.000319

CONCLUSION :

• From a analysis standpoint case 2 is preferable since max stress and strain are less compared to case 1 for the same loading condition. This casused by additional holes that act as a stress relliver in this model. so it can be subjected to more load if required. which gives the possibility of reducing material cost and lighter object.
• From a manufacturing standpoint case 1 is perferable as the making of additional two holes requires additional operations to be performed which requires additional times.