Week 1 Stress Concentration on a Plate with hole

OBJECTIVE :- Design and Perform a Tension test on a plate in two different cases and compare the results

Case :1

Design a plate with a hole model.
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.

Consider you are a Product Engineer in an Automotive industry.

You are assigned the following responsibilities:

• Compare the deformation and maximum stress developed on a structural steel model for the 2 cases                               
• From an analysis standpoint, which of the design will you select? Explain why?  
• From a manufacturing standpoint, which of the design will you select? Explain why? 
• Write a Detail Report.

CASE SETUP 

case1

• Static structural selected from analysis system 
• Engineering data - it can be addited to add or remove materials from the library, structural steel selected from library for this projct.
• Geometry - we can directly create geometry from space claim or we can import the cad model, but in this project we created 3D cad model in  space claim.

                          

• open mechanical module by double clicking model option in project schematic
• Rename the model and assign structural steel to the model.

• Create a tetra mesh with an element size of 4mm

   

• Create a boundary conditions as per the given question

 

• Request for von-mises enginering stress, von-mises enginering strain and total deformation.These are the typical output requests.
• To get the solution go to solution-right click- solve.

case2

• case setup is same for both (case1&2) cases but geometry is different, in this we created a plate with 3 holes as per given dimensions.

RESULTS :-

Type	case 1	case2
von-mises enginering stress
von-mises enginering strain
total deformation

CONCLUSION

• Stress is lower in case 2 ( 0.57699mpa) compare to case1 ( 0.6018), due to the flow of stress lines being smoother than case1.
• Deformation is higher in cas 2 (0.00029729) compare to case 1( 0.00027493) due to the additional hole.
• In Analysis point of view case2 design is safer due to low stress but defrmation is littile higher but it is negligible.
• In Manufacturing point of view case1 design is good, because case2 design requires two additional holes to be drilled only to obtain small decrease in stress levels.

RECOMMENDATION

I recommnded case1 model over case2, because case2 model needs more manufacturing cost and time. Assembly cost of case2 is more because it requires more fixtures.