How to give impact load in staad. i need to check the system will pass the soft body ( 300 joule) and hard body impact test as per the EOTA and ETAG 003. Whats the general procedure to convert the energy (joule or Nm ) to load ( to model in staad ) . Please help me to find a solution .
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How to give impact load in STAAD Pro V8i
- Thread starter ARNAR
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For a impact load in STAAD: You can just put the load in as a quasi-static load (i.e. the load multiplied by a impact factor).
Or: click on the "Load Page" icon (on the toolbar; it looks like a hand above an arrow). Then click "New" (on the (lower) right hand side of the screen; the window with it appears when you click on the "Load Page" icon). Then (under the "Definitions" tab), click on the "Time History", and a "Define Time History" tab should appear. In that window (with the "Define Time vs. Force" & "Force" options selected), you should be able to define your force vs. time.
Or: click on the "Load Page" icon (on the toolbar; it looks like a hand above an arrow). Then click "New" (on the (lower) right hand side of the screen; the window with it appears when you click on the "Load Page" icon). Then (under the "Definitions" tab), click on the "Time History", and a "Define Time History" tab should appear. In that window (with the "Define Time vs. Force" & "Force" options selected), you should be able to define your force vs. time.
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@ WARose : Thanks for your advise. i want to check the partition wall system safe against the soft body impact test. In soft body impact test, hitting a softy body of mass 50kg with an energy of 300 joule. If i put the load quasi static load what impact factor i need to take ?? if i proceed with time history , how can we find out the force and time using these ( load and energy) ?? please help me to find solution.
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I think one of the better methods of figuring impact force is the method/formulas in Blodgett's 'Design of Welded Structures' that takes into account stiffness. (See Section 2.8.) You could probably figure it that way.
Another way could be the impulse-momentum equations. I.e. F= mv/Δt. (Where m=mass of object, V=velocity at impact, and Δt= impact time.) The problem with that method is: It's hard to know what the duration of impact will be. (It can range from as high as 300 ms to as low as 0.1 ms. On rare occasion even be shorter than that 0.1.)
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- #9
Probably the most relevant one:
F= Wb + (Wb2 + ((K*Wb*V2)/g))1/2
Where:
F= Impact Force [lbs]
Wb= weight of body [lbs]
K= stiffness at point of impact [lbs/inch]
V= Velocity at impact [in/sec]
g= acceleration of gravity [386.4 in/sec2]
This formula is built around a falling object striking a beam with one degree of freedom.
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