A simplified method of designing for vibration is commonly used in the UK and has been implemented in the program for composite beams. This method is based on calculating and limiting the natural frequency of the beam. When either BS 5950:1990 or BS 5950:2000 is selected as the Beam Steel Design Code, an additional set of Criteria items to specify the Minimum Frequency allowed are available in the Criteria > Design Defaults command. A different value can be specified for short span beams than for long span beams. Specifying limits of 0.0 means that there are no limits; the Simplified approach will not be used to check and control vibration.