Applies To
	Product(s):	AutoPIPE
	Version(s):	V8i
	Environment:	N/A
	Area:	Modeling
	Subarea:
	Original Author:	Bentley Technical Support Group
	Date Logged & Current Version	Sept. 2015 09.06.02.06

Problem:

what I am really after is some assistance on dynamic modelling of the blast event.
I am applying a triangular blast profile over a very short time period which I am doing to each node of the affected pipe. To do this I am using a time force history and applying this to the nodes; some with a time delay.

I would like some more information on the best way of doing this and also, and most importantly, is it possible in AutoPipe to obtain a force time history of the reactions at the supports? At the moment, I seem to get just one force figure at each reaction which I assume is the maximum reaction force felt by that support.

Answer:

 AutoPIPE will only show the maximum response or reaction. Or see Time History Post Processor plots that are available in AutoPIPE 09.06.xx.xx and higher.

When doing short duration load, suggest the cut-off frequency should be increased to 200 Hz and automatic mass points added up to 200 Hz. We also recommend to use ZPA option.

For this type of load the static analysis is just as good but can be conservative by a factor of 2, since you will assume a dynamic amplification of 2.0. Of course static response will ignore phasing.

Static analysis is a good way to check results since it bounds the response. Wind can be applied to exposed segments. You may have to split a pipe into two segments using Edit> Segment> Split if wind is applied to one part of the pipe segment.

See Also

Model Blast Loading in AutoPIPE

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

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