Applies To
	Product(s):	STAAD.Pro
	Version(s):	All
	Environment:	N/A
	Area:	Analysis Solutions
	Subarea:	Response Spectrum Analysis
	Original Author:	Bentley Technical Support Group

Why are beam graphs not displayed for response spectrum load cases in STAAD.Pro?

For a response spectrum load case, the responses that you get at the member start/end and also at intermediate section locations, are all individual maximums. In other words these values do not occur simultaneously at the different sections along the member length and so it is not correct to plot a graph with those values. In addition, when modal responses are combined to generate the final output for a response spectrum load case, the signs are lost and so plotting a graph with such numbers is of little value.