2011PNWSC_Loading.mp4

Loading Device, Deflection Measurement, and Sway Measurement devices to be used at the 2011 ASCE Pacific Northwest Student Conference Steel Bridge event.

Category:

Education

Tags:

• Steel
• Bridge

[quimbytb]

@gzamac

Darn character limits... restating the last reply:

Each cross head with plywood grating weights between 75# and 80# (exact weight is marked on the crossheads). The rules allow for 250# (50# grating + 200#) preload on backspan and 100# (50# grating + 50#) preload on cantilever... so weight is Okay as long as we add more.

[quimbytb]

@gzamac

The deflection devices are physically independent of the loading devices, so your concern regarding deflection of the cross heads is irrelevant. They can deflect all they want to without effecting the deflection measurement. The rules allow for 250# (50# grating + 200#) preload on backspan and 100# (50# grating + 50#) preload on cantilever... so weight is Okay.

[quimbytb]

@gzamac

The deflection devices are physically independent of the loading devices, so your concern regarding deflection of the cross heads is irrelevant. They can deflect all they want to without effecting the deflection measurement.



[quimbytb]

@gzamac

Thanks for giving us a chance to clarify your concerns.

First of all, the calipers measure to edge of line to edge of line so width of the pencil line is not a concern. Also our tests show that measurements are repeatable to the nearest 0.005 in by multiple readers. That's still pretty good.

[gzamac]

That is awesome that calipers, accurate to 1/1000 of an inch are being used to measure pencil marks that are 1/16 of an inch wide, what a joke. Did anyone check the localized deflection on those wood beams when 1600 pounds of force is applied? For that matter, did anyone make sure that conglomeration of pallets and posts weighs 200 pounds? I poo on this!