Week 1 Stress Concentration on a Plate with hole

Week 1:

Sress Concentration on a plate with Hole:

Aim:To compare the deformation and maximum stress developed on a structural steel for both the cases (1&2) from analysis stand point and manufacturing stand point.

Objective:

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.

Procedure:

CASE 1:

• Firstly open the ANSYS Workbench software.
• select 'Static Structural' from analysis system.

• Use the default material which is a 'Structural steel'.
• Then click on Geometry it will re-direct to another tab named as 'Space Claim'.

• Then create a rectangular plate with a hole and assign the dimensions as mentioned.

• And then pull the created plate with a thickness of 30mm with  the pull option.

• After that close the Space claim window.
• Then right click on the model tab and click 'update' then it will open another window named as 'ANSYS Mechanical'.

• Then mesh the model using 'automesh' with an element size of 5mm.
• As it is a solid structure we need to convert it from 2D element to 3D element.
• So, right click on mesh and then insert a method.
• Then select the model and click apply and in method select 'Tetrahedrons'.

• After meshing the model the image will be as follows.

• After that we need to fix the left end of the plate using fixed support.

• Then select the side and click on 'apply' then it will be fixed at one end as follows.

• We need to select the force end on right side where the force is applied.

• Then we need to assign the force at one end by defining using co-ordinate system.

• Assign the force of 500N at a right end of the plate according to Co-ordinate axis.
• Then click on the solution it gives us the solution information as follows.

• Then after we need to get the output results for this model as equivalent stress and total deformation.
• For that right click on Solution>Insert>Stress>Equivalent(Non-mises).

• For Total deformation Solution>Insert>deformation Total.

• And finally after that we evaluate the result by right click on the solution tab and check evaluate all results.

Equivalent Stress:

Total Deformation:

Final Images:

CASE 2:

• Create a rectangular plate with three holes and assign the dimensions as mentioned.

• And then pull the created plate with a thickness of 30mm with  the pull option.

• After that close the Space claim window.

• Then right click on the model tab and click 'update' then it will open another window named as 'ANSYS Mechanical'.

• Then mesh the model using 'automesh' with an element size of 5mm.
• As it is a solid structure we need to convert it from 2D element to 3D element.
• So, right click on mesh and then insert a method.
• Then select the model and click apply and in method select 'Tetrahedrons'.

• After meshing the model the image will be as follows.

• Then select the side and click on 'apply' then it will be fixed at one end.

• We need to select the force end on right side where the force is applied.

• Then we need to assign the force at one end by defining using co-ordinate system.

• Assign the force of 500N at a right end of the plate according to Co-ordinate axis.
• Then click on the solution it gives us the solution.

• And finally after that we evaluate the result by right click on the solution tab and check evaluate all results.

Equivalent stress:

Total Deformation:

Final Images:

Results and comparision:

Equivalent stress:

                                             Maximum(MPA)                     Mininimum(Mpa)                     Avg(Mpa)

         CASE 1                              0.599913                            0.017603                            0.16972

         CASE  2                             0.58465                              0.0045513                          0.16975

CASE 1 Image:

CASE 2 Image:

Total Deformation:

                                                Maximum(mm)               Minimum(mm)              Avg(mm)

    CASE 1                                0.00027479                             0                         1.367e-004

    CASE 2                               0.00029698                             0                         1.4492e-004

From the above Comparisions

• The deformation in Case 2 is high when compared to Case 1.
• Whereas for maximum stress the case 1 is high compared to that of case 2.

Selection of design from Analysis point of view:

 In analysis point of view we can go with case 2 because it has less 'stress' compared to case 1.The stress concentration around is very low and it gives a better flow of stress waves in the element.The stress has been distributed around the three holes on the plate.

Selection of design from a Manufacturing point of view:

 In manufacturing point of view we can go with case1,As to reduce the wastage of the material,production cost and time as well.In the case 1 it is very simple design that requires less effort in manfacturing.

Conclusion:

From the above cases we get a conclusion we get a conclusion that stress developed as maximum in case 1 compared to that of case 2.And then deformation is higher in case 2 comapared to that of case 1.