Applies To
	Product(s):	STAAD.Pro
	Version(s):	ALL
	Environment:	ALL
	Area:	Analysis Solutions
	Subarea:	Time History Analysis
	Original Author:	Sye Chakraborty Bentley Technical Support Group

For one of our projects we are designing a platform sitting on steel framing. On the platform we have 5 Blowers. I was wondering if STAAD can take into account the vibration loads coming from Blowers. I could not find in Technical Reference as well as online manual.

In order to analyze a structure for dynamic loading which does not fall under the category of ground motion (earthquakes), no matter what the origin of the dynamic loading, it will have to be reduced to one of two types that STAAD can recognize :

a) Harmonic loading : This requires that the load be described in the form of a Sine or Cosine function. Input data in the form of the peak amplitude, operating frequency of the equipment, number of cycles, phase angle, etc. will have to be obtained by the user, and specified as input to STAAD.

b) Random vibration which can be described in the form of discrete time-force pairs. The force values and the time at which they act have to be specified in this case.

Details on both types on available in the STAAD.Pro Help sections:

General Engineering Theory > G.17 Analysis Facilities > G.17.3 Dynamic Analysis
Technical Reference of STAAD Commands > TR.31 Definition of Load Systems > TR.31.4 Definition of Time History Load
Technical Reference of STAAD Commands > TR.32 Loading Specifications > TR.32.10 Dynamic Loading Specification > TR.32.10.2 Time Varying Load for Response History Analysis

Example problem 22 of the STAAD.Pro Examples Manual for type (a) - Application Examples > EX. American Design Examples > EX. US-22 Time History Analysis for Sinusoidal Loading
Example problem 16 of the STAAD.Pro Examples Manual for type (b) - Application Examples > EX. American Design Examples > EX. US-16 Time History Analysis for Forcing Function and Ground Motion.