All of the following examples are based on a rectangular cross section beam subject to a pure bending moment.

1. Beam with a single, centrally located hole. The element mesh and loading conditions are shown below. Note that symmetry allows us to model only one half of the beam. The displacement constraints at the left end are the result of this symmetry. This is true for all of the examples. Click here for PDF image.
2. The stress component in the X-direction (along the beam) is shown in the contour plot:
3. The stress gradient across one half of the beam at the hole is shown in this graph:
4. Beam with two central holes. The element mesh and loading conditions are shown below. Note that symmetry allows us to model only one half of the beam. The displacement constraints at the left end are the result of this symmetry.  Click here for PDF image.
5. The stress component in the X-direction (along the beam) is shown in the contour plot:
6. The stress gradient across one half of the beam at one of the holes is shown in this graph:
7. The stress gradient across the beam at the point of maximum stress on the outer fibres is given here.

The next 4 plots show the beam with two notches used in your actual lab experiment. The stresses shown were obtained with a 10 kg. load on the notched beam. These can be scaled linearly to match the actual load used.

Note that all stresses are given here in units of psi. ( 1 psi  =  6896 Pascal )

1. Beam with two central notches. The element mesh and loading conditions are shown. Click here for PDF image.
2. The stress component in the X-direction (along the beam) is shown in the contour plot:
3. The stress gradient across the beam at the notches is shown in this graph:
4. The stress gradient across the beam at a point distant from the stress concentration is shown here.