DESIGN AND OPTIMIZATION OF A PLATE WITH HOLES
OBJECTIVE:
To analyze the stress concentration of a plate with modifications using Finite Element Analysis in ANSYS.
Steps involved:
1.Material Selection
2.Designing the model.
3. Meshing of the model
4.Applying the Boundary conditions.
5.Analysing the stresses and deformation acting on the plate.
CASE 1: The plate has one hole and the stress concentration is simulated.
Geometry Details:
Length=300mm, Height=120mm, Thickness=30mm
Circular Hole at the center:
Diameter=60mm
1.MATERIAL SELECTION:
The material used in this case is structural steel.
2.DESIGNING OF THE MODEL:
3.MESHING THE MODEL:
A mesh size of 2 mm is used in this case to get the possible efficiency and work within the limitations of computational domain of ANSYS ACADEMIC VERSION.
4.APPLYING THE BOUNDARY CONDITIONS:
The plate is given fixed support on one end and a tensile load of 500N is given on the other end.
RESULTS:
5.ANALYZING THE STRESSES AND DEFORMATION ACTING ON THE PLATE:
CASE 2:
The plate has three holes and the stress concentration is simulated.
Geometry Details:
Length=300mm, Height=120mm, Thickness=30mm
Circular Hole at the center with two holes:
Two holes are placed 90mm away from the centered hole.
Diameter=60mm, Diameter of Two holes=30mm
1.MATERIAL SELECTION:
The material used in this case is structural steel.
2.DESIGNING OF THE MODEL:
3.MESHING THE MODEL:
A mesh size of 2 mm is used in this case to get the possible efficiency and work within the limitations of computational domain of ANSYS ACADEMIC VERSION.
4.APPLYING THE BOUNDARY CONDITIONS:
The plate is given fixed support on one end and a tensile load of 500N is given on the other end.
RESULTS:
5.ANALYZING THE STRESSES AND DEFORMATION ACTING ON THE PLATE:
CONCLUSION:
It is seen that the stress concentration in 2nd case is less than 1st case.This is because the stress lines are similar to fluid flow lines. If the cross-section changes steeply then it is seen that the fluid flow lines gets concentrated in one area and so is the case with stress concentration. However when the cross-section changes gradually like in the presence of two small holes and a big hole in the middle as given in case 2, the stress also increases gradually in those areas and the stress concentration is not huge.
If considered the case of fluid flow, the smaller holes changes the direction of fluid slowly and hence we get nearly streamlined flows in this case but with the case of a single big hole, the direction of velocity of flow changes abruptly.Hence it is seen that the stress concentration in case 2 (0.57992 MPa) is pretty lower than that of case 1 (0.68487MPa).
1.From design point of view
I would go with the second case (case2) since the stress concentration is lower, the factor of safety in that case is also lower and we can eventually save a lot of cost by saving materials as high higher stress cconcentration would result in more material since the factor of safety in that case would also be higher.
1.From Manufacturing point of view
2. Considering the fact that I am not at all considering the stress factors, from Manufacturing point of view I would go with case 1 as the material lost in machining purposes is also less. So the material cost gets saved in this case.