.png)
Individual and multiple openings can be added to a beam. The openings can be circular, rectangular, elongated or end notches and positioned at any reasonable height within the depth of the web. Edge stiffeners can be added to the opening if required. Note that these openings do not have any effect on the overall depth of the beam, unlike the cellular beam option where the beam section depth increases when the openings are added.
.png)
Method 1.
Circular openings can be easily defined by entering the distance 'X(m)' to the centre of the opening from the start of the beam. The hole diameter in mm is specified, along with the top distance down from the top of the beam to the top of the opening. The opening will now appear graphically on the beam. If an edge stiffener is required, the area in mm2 of the stiffener is defined. This is the area of the top stiffener and the same area of stiffener will be repeated at the bottom of the opening. The distance from the edge of the opening to the stiffener can also be specified. The calcs will suggest sizes for these stiffeners as single or doubled sided plates. Note that while the program will give suggested stiffener plate and weld sizes, it is up to the Engineer to check the design of these elements.
Method 2.
For a series of equally spaced openings a quick method can be used. Rather than entering all the individual openings dimensions, you can specify the first and second opening distances and the last opening location. Then press the 'R' button and the program will automatically add all the intermediate openings based on the spacing between the first and second entries until it reaches the last opening location.
.png)
.png)
Method 3.
Another quick method of adding equally spaced circular openings is shown below. Define the start distance, the number of openings to be added and their spacing. Then press the '+' symbol to automatically add these openings.
.png)
Rectangular and elongated openings can be added in the same way as for circular openings using methods 1 and 3 from above.
For an elongated opening place a 'Y' in the Elongation column.
.png)
.png)
End notches on beams can be considered too. Specify the distance to the centre of the length of the notch. Add a 'Top' dimension - this is the distance down from the top flange of the beam to the top of the notch. Note that the size of the notch is not controlled by the depth and width entries in this case. Stiffener areas can be added if required.
.png)
.png)
The colour of each opening is significant. There are 4 possible coloured backgrounds to the openings.
Red - a stress failure at the opening.
Blue - a dimensional failure at the opening.
Green - passing all checks and detailed output provided in the calcs.
White - passing but only a summary calc is shown in the calcs for these particular openings.
When a blue dimensional failure is shown, the opening should be moved in the direction of the yellow circle outline.
For example, the opening at the left hand end of the beam below is too close to the end and needs to be moved in-board.
The second opening is too close to the point load and needs to be moved laterally away from the point load.
The third blue opening is too close to the bottom of the beam and need moved upwards.
With the passing openings (green and white backgrounds) full calcs are shown for the critical openings where there is max moment or max shear (green) and summary calcs for the non-critical openings (white).
.png)
The openings are checked against the relevant British and EuroCode design standards and other technical publications, particularly SCI Publication P355 - Large Web Opening Design in Composite Beams.