Week 1 Stress Concentration on a Plate with hole

Question: Analysis of Maximum Deformation and Maximum Stress developed on a plate with hole/holes using ANSYS

-------------------------------------------------------------------------------------------------------------------

CASE: 1

• Open Ansys Workbench (I have used Ansys Workbench version: 2021 R1 Student version)
• Toolbox -> Analysis Systems -> Double click on the Static Structural
• Project Schematic:

• Engineering Data: Keep the material is “Structural steel” with its all default properties.

• Geometry:

- We can easily import solid model from any software to Ansys workbench just by converting it into a supported file. i.e. STEP, IGES, X_T (Para solid). Also we can use Ansys SpaceClaim for make solid model.

- Here I have used: Solid works 2020 Part file (.sldprt) -> Make STEP file.

- Switch over Ansys Workbench and then Right click on Geometry -> Import Geometry -> Browse… Specific folder -> Select Supported file. I.e. STEP file.

• Model:

- Double click on Model and appear following screen.

- Now Ansys Mechanical Enterprise starts.

- Check following details:

• Geometry for the Material -> STEP file.
• Material -> Structural steel.

• Mesh:

- In the “Mesh”: Right click to Insert -> Method and then change “Tetrahedrons”. Select the geometry from working area -> Apply. Now, we can see the “1 body” under Geometry details.

- Generally Patch conforming method is used for Mesh.

- In the “Mesh” -> Body Sizing -> Set Element size 8.0 mm and afterwards right click to generate the mesh.

- After generating the “Mesh” in the geometry, it looks like as follows:

- In Statistics: Nodes =26239 and Elements = 17145 observed.

- In “Static Structural”: Right click to Insert -> Fixed support and then Force. Select the Fixed support at left side face shown in following figure and select opposite face for Force. Now, edit the value of Magnitude = 500N.

- In “Solution”: Right click to Insert -> Deformation -> Total Deformation and then Insert -> Stress -> Equivalent (Von-Mises) Stress.

- Click Toolbars -> Solution -> Solve and after solving again click to Total Deformation and Equivalent (Von-Mises) stress and evaluate all the results.

Result (Case-1):

• Total Deformation

Max. Deformation	0.00027485 mm
Min. Deformation	0 mm

• Equivalent (Von-Mises) stress

Max. Stress Concentration	0.58782 MPa
Min. Stress Concentration	0.019692 MPa

--------------------------------------------------------------------------------------------------------------------------

CASE: 2

• Open Ansys Workbench (I have used Ansys Workbench version: 2021 R1 Student version)
• Toolbox -> Analysis Systems -> Double click on the Static Structural
• Project Schematic:

• Engineering Data: Keep the material is “Structural steel” with its all default properties.

• Geometry:

- We can easily import solid model from any software to Ansys workbench just by converting it into a supported file. i.e. STEP, IGES, X_T (Para solid). Also we can use Ansys SpaceClaim for make solid model.

- Here I have used: Solid works 2020 Part file (.sldprt) -> Make STEP file.

- Switch over Ansys Workbench and then Right click on Geometry -> Import Geometry -> Browse… Specific folder -> Select Supported file. I.e. STEP file.

• Model:

- Double click on Model and appear following screen.

- Now Ansys Mechanical Enterprise starts.

- Check following details:

• Geometry for the Material -> STEP file.
• Material -> Structural steel.

• Mesh:

- In the “Mesh”: Right click to Insert -> Method and then change “Tetrahedrons”. Select the geometry from working area -> Apply. Now, we can see the “1 body” under Geometry details.

- Generally Patch conforming method is used for Mesh.

- In the “Mesh” -> Body Sizing -> Set Element size 8.0 mm and afterwards right click to generate the mesh.

- After generating the “Mesh” in the geometry, it looks like as follows:

- In Statistics: Nodes =26096 and Elements = 16886 observed.

- In “Static Structural”: Right click to Insert -> Fixed support and then Force. Select the Fixed support at left side face shown in following figure and select opposite face for Force. Now, edit the value of Magnitude = 500N.

- In “Solution”: Right click to Insert -> Deformation -> Total Deformation and then Insert -> Stress -> Equivalent (Von-Mises) Stress.

- Click Toolbars -> Solution -> Solve and after solving again click to Total Deformation and Equivalent (Von-Mises) stress and evaluate all the results.

Result (Case-2):

• Total Deformation

Max. Deformation	0.0002971 mm
Min. Deformation	0 mm

• Equivalent (Von-Mises) stress

Max. Stress Concentration	0.57397 MPa
Min. Stress Concentration	0.0034984 MPa

Comparison:

• Compare the Deformation and Maximum stress developed on structural steel model for the above 2 cases:

	Plate with one Hole	Plate with three holes	Comparison
	(Case-1)	(Case-2)
Element size (mesh)	8	8
Nodes	26239	26096	↓
Elements	17145	16886	↓
Max. Deformation (mm)	0.00027485	0.0002971	↑
Min. Deformation (mm)	0	0	-
Max. Stress (MPa)	0.58782	0.57397	↓
Min. Stress (MPa)	0.019692	0.0034984	↓

Here, I have observed that:

• Stress Concentration: In Case-1: 58782 MPa and In Case-2: 0.57397 MPa. So, In the Case-1 Stress Concentration is more than compared to Case-2.
• Maximum Deformation: In Case-1: 00027485 mm and In Case-2: 0.0002971 mm. So, In the Case-1 Maximum Deformation is less than compared to Case-2.

From an analysis standpoint, which of the design will you select? Explain why?

• From the Analysis side: Plate with three holes (Case-2) is selected because of less Stress concentration and it undergoes with notable Maximum deformation, when load 500N applied.
• This plate having less weight, because of extra 2 nos. of holes machined.

From a Manufacturing standpoint, which of the design will you select? Explain why?

• From the Manufacturing side: Plate with single hole (Case-1) is selected because of less machining cost, less time consumed during machining, less tooling
• There is no need to change tooling frequently, because of single hole required in the centre compared to three holes (different diameters) on the plate.

Conclusion:

• The structure analysis of both the cases is performed in Ansys 2021 R1. The stress concentration and Maximum deformation are defined particulars.
• Case-2 has less amount of Stress Concentration compared to Case-1. While, Case-2 has more amount of Maximum Deformation compared to Case-1.