Applies To
	Product(s):	AutoPIPE
	Version(s):	2004, XM, V8i
	Environment:	N/A
	Area:
	Subarea:
	Original Author:	Bentley Technical Support Group
	Date Logged & Current Version	Sept. 2015 09.06.02.06

Problem:

What is the recommended method to account for a vapor cloud (external) explosion, in this case defined as a pressure of 0.3 bar for a duration of 0.3 seconds.

Answer:

The vapor cloud pressure load can be modeled using a wind load. The wind can be entered as a user profile. Shape factor of 0.7 can be used with a dynamic amplification factor of 2.0. Total pressure would be 0.3*2*0.7=0.42 bar.

The dynamic amplification factor is not a setting. Just need to amplify load to account for dynamic effect. Wind is static load.

The allowable for this load case will be based on the code calculation for an occasional load case. The user will need to determine if this is acceptable or not for their situation. If the automatic allowable calculations is not acceptable, have the following 2 choices:

1.  For occasional loads - k factor can be manually updated by the user and set to any other value than the default value of 1.33. This can come in handy for the user for trying to define the allowable as a factor of allowable strength.

or

2. The allowable can be manually changed on the Tools> Combination> Code Comb tab (see AutoPIPE help for details).

See Also

Model Blast Loading in AutoPIPE

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

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