Week 1 Stress Concentration on a Plate with hole

Objective:

The objective was to compare two plates under equal loading. The first plate is of 300mm length, 120mm in height and 30mm in thickness, it also contains a hole in the center of 60mm diameter. the second plate has the same dimensions as of the first plate apart from the addition of two extra holes which are at a distance of 90mm away from the center of the center. the left side of both models is fixed while the right side was applied a force of 500N. The comparison of deformation and maximum stress was done.

Comparing deformation and maximum stress developed:

Deformation:

Both models performed very well as they showed very less deformation when applied a force of 500N. The plate with one hole had a deformation of 0.0002752mm whil the plate with three holes had a deformation of 0.0029618mm. The maximum deformation on both models occured at the end applying the force. The deformation that occured in the plate with one hole is uniform throughout the length of the plate but due to the addition of two more holes the deformation rate increases with each passing hole, i.e, the deformation from the first hole to the second from the left is less than the deformation occuring between the second hole and the third one.

Maximum Stress:

The maximum stress developed in the plate with one hole is 0.59792 MPa and the plate with 3 hole is 0.54997MPa. Both the maximum stress has occured on the center hole top part. while the minimum stress has occured on the left leading edge of the only hole in one hole plate the minimum stress has occured at the first hole from the left on the 3 hole plate. On both models there is also a lot of stress developed at the bottom of the center hole howerver the stress at the bottom on the single hole plate is much closer to the maximum value rather than the 3 hole plate where the value is not as close as the one in one hole plate.

Selection of model from an analysis point of view:

I would select the model with one hole. the deformation is marginally less eventhough the maximum stress is comparitively higher than the three hole model. i selected this model because when comparing the higher stresses are only found in the top and bottom end of the only circle but in the 3 hold model higher level of stress are also found at the top and botton of the smaller circles. also looking into the whole plate the one hole model is less stressed as a whole unit when compared to the 3 hole model.

Selection of model from a manufacturing point of view

From a manufacturing point i would select the model with one hole as it only has one hole it is easier to manufacture and also mean less wastage of materials for essentially almost equal performance. Although the three hole model is lighter than the one hole model but considering the lease of manufacturing one hole rather than three holes of two size coupled with the loss of material caused by the three hole model makes the choice on single hole model economical.

The one plate model was constructed first in space claim and then given for meshing, later by making another standalone system i imported the geometry and disconnected the connection in order for me to edit the model to include two more holes. I initially exploded the imported geometry drew two more circles pulled and later got rid of the additional surfaces created by the other two circles. Later the mesh element size was kept at 8mm on both models due to the constraints of Ansys Student Edition which was evident to me only after solving the model with an element size of 1mm initially and then 5mm. Although the number of elements and nodes were in the limit there was some issue later on in the solving phase. after this issue was solved the solution for deformation and stress was selected. finally the above mentioned results were found out. The resultant Analysis obtained is also attached here.