Week 1 Stress Concentration on a Plate with hole

AIM:

To perform static structural analysis on two plates of the same dimensions but with a different numbers of holes and analyze the stress, deformation etc. acting on the plates.

Procedure followed:

Case 1:

1.)Design Plate A with a single hole.

2.)Meshing

Case 2:

1.)Design Plate B with 3 holes.

2.)Meshing

3.)Compare the simulation results.

Designing of plates of structural steel with Ansys spaceclaim software.

The plate is modelled with the following dimensions of 300 mm length,120mm width & 30 mm thickness with 60 mm diameter hole with centre atbthe midpoint of lines of length & width.

Material specification:

Density	7.85e-006 kg mm-3
Isotropic Secant Coefficient of Thermal Expansion	1.2e-005 C-1
Specific Heat Constant Pressure	4.34e+005 mJ kg-1 C-1
Isotropic Thermal Conductivity	6.05e-002 W mm-1 C-1
Isotropic Resistivity	1.7e-004 ohm mm

Desiging of plate A with 1 hole:

Meshing of single hole plate:

The plate is meshed with tetrahedron elements of 6mm size under Ansys Academic License.

After the model is meshed, the loads are applied on the model. A fixed support is given on one side while a tensile load of 500 N is given on the other. The loads are as shown in the image below:

The solutions are applied & at the end Von mises stress applied with total deformation.

Desiging of plates B with 3 holes one at the centre of 60 mm diameter & other two at 90 mm from centre with 30 mm diameter with Ansys spaceclaim:

Meshing of 3 hole plate B:

The plate is meshed with tetrahedron elements of 3mm size under Ansys Academic License.

After meshing plate B is fixed at one end & at the other end 500N tensile force is applied.

Results obtained:

The Equivalent stress for the two cases are compared.

Time [s]	Minimum [MPa]	Maximum [MPa]	Average [MPa]
1.	2.1257e-002	0.60547	0.16858
2.	1.2799e-003	0.58267	0.16807

The Equivalent stress comparision is plotted below:

The Total Deformation for the two cases are compared below.

Time [s]	Minimum [mm]	Maximum [mm]	Average [mm]
1.	0.	2.7472e-004	1.3713e-004
2.	0.	2.9722e-004	1.4704e-004

Total deformation comparision of plate A & B is plotted below:

Conclusion:

Analysis was doen keeping into account nodes & elements as per Ansys Academic License.

In plate B due to presence of 3 holes lesser material present so low size element of 3 mm used during meshing so we get more accurate result for plate B compared to plate A.From analysis standpoint plate B is more close to accuracy than plate A.

On comparison of the Total Deformation experienced by the model A having only a slight difference in the average value is evident of the order of 0.0991mm with Case 2 having a higher value. Maximum deformation in the two models has a difference of the order of 0.225mm.

On comparison of the Equivalent stress experienced by the model in the A having a difference of 0.00051 MPa is evident in the average value of equivalent stress. But the tension force experienced in case 2 is lesser than than Case 1.

From the manufacturing point of view of the component in case 1 involves lesser drilling than Case 2. This means lesser work involved whereas in Case 2, lesser material is used. So from manufacturing point of view design 1 is to be selected.