Week 1 Stress Concentration on a Plate with hole

OBJECTIVE

Design a Plate with a hole in the center and perform a static structural simulation using Ansys. Discuss the results for the below 2 cases with Boundary condition as left face fixed and a load of 500 N acting on the right face (Pull)

CASE 1 - Plate with a hole in the center

Case 2 - Plate with multiple holes

Outputs

• Compare the deformation and maximum stresses in both the cases
• Explain which model to use from an analysis perspective.
• Explain which model to use from a manufacturing perspective

PROCEDURE

There are two cases to be discussed here and steps used in building both the simulation is discussed below.

Step 1 - Geometry

• Open Spaceclaim from Wokebench -> Static structural window.
• Create a 2D geometry using Spaceclaim.
• Select the Pull option to assign a thickness of 30mm.

Step 2 - Material Assignment

• Open Engineering Materials and select the required material.
• Structural steel is a default material in ANsys

Step 3 - Meshing

• Mesh -> insert -> method -> method = tetrhedrons
• Element size = 7 mm

Step 4 - Boundary Condition

• Fixed support on left side
• The force of magnitude 500 on the right side

Step 5 - Solution

• Extract deformation, Equivalent stress, and equivalent strain.

RESULTS

	CASE -I Plate with single hole		Case 2 - Plate with multiple holes
Geometry
Mass	7.8121 kg		7.4792 kg
Mesh
Mesh Quality
Boundary Condition
Deformation	max deformation = 0.00027488 mm		Max deformation = 0.00029 mm
Equivalent Stress	max stress = 0.59029 MPa		max stress = 0.57047 MPa
Equivalent Strain	Max strain = 2.9522 e-6		Max strain = 2.8532e-6

CONCLUSION

Based on the static structural simulation done for both the cases, deformation, stress, and strain were compared. based on these results we can conclude the following things

• From an analysis standpoint, case 2 is preferable since max stress and strain are less compared to case 1 for the same loading condition. This is caused by additional holes that act as a stress reliever in this model. So it can be subjected to more load if required. Also, the mass is less in Case 2 compared to case 1 which gives the possibility of reducing material cost and lighter object.
• From a Manufacturing standpoint, case 1 is preferable as the making of additional two holes requires additional operations to be performed which requires additional time.