STRESS CONCENTRATION ON A PLATE WITH HOLE

AIM

To perform Static structural analysis on a plate with a hole geometry

Case 1: Plate with a hole (increased thickness).

Case 2: Plate with multiple holes.

Case :1

To Design a plate with a hole with condiotions mentioned below.

Plate dimensions:

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

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

PROCEDURE

• Open ansys workbench .
• Update the material module as structural steel.
• IN then geometry model open new place claim and design the plate according to the given dimensions.
• Then extrude the geometry.
• Then update the model and edit it.
• In the mechanical tab update the mesh into tetrahedrons and generate it.
• Then in the static structural tab assign the BC
• A fixed edge(left) and force is dissipated in right side
• Then evaluate the solution.

STEP 1

STEP 2

STEP 3

STEP 4

STEP 5

STEP 6

Case :2

To Design a plate with a hole with condiotions mentioned below.

Plate dimensions:

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

smaller holes 90mm away from the center

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

STEP 1

STEP 2

STEP 3

STEP 4

STEP 5

STEP 6

COMPARIONS

D1(ONE HOLE)

D2 (THREE HOLE)

DEFORMATIONS.

The plate with one whhole is having a deflection of 2.7489e-004mm and the plate having three holes has the maximum deflection of 2.9692e-004mm .

S1(ONE HOLE)

S2(THREE HOLE)

The plate with one whhole is having a stress concentration of 9.6381e-003MPA and the plate having three holes has the minimum stress oncentration of 4.259e-003MPA.This is because the stress lines are similar to fluid flows , hence the cross sectional in (onehole) is steep and then the stress gets accumulated on single area. In the second case the cross sectional is gradually increasing due to the presence of two holes the stress concentration is not massive.

DESIGN POINT OF VIEW

From an analysis standpoint, i would go with second case ( 3 holes) since the

• stress concentration is lower
• FOS is lower

we can save lot of materials

If we would have gone with the First case ( 1 hole)

• stress concentration is higher
• FOS is higher

This would result in consuming higher stress concentration materials and the cost is higher.

MANUFACTURING POINT OF VIEW

From a manufacturing standpoint, I would go with first case ( 1 hole) since it has

• Less machining time
• low material cost

If we would have gone with the second case ( 3 hole) it would have

• More machining time
• Much material cos