## hand calculation simple frame

## hand calculation simple frame

(OP)

Hello guys,

Im really struggling to do a proper hand calculation for some reason on this really simple frame. none of my methodes seem to solve this one. i need to know what the reaction forces are in the 2 supports at the bottom. Does anyone know something on how to solve this situation? the reaction forces/moments are as you can see already calculated by a simulation.

I hope someone can me help out!

Greetings from the netherlands!

Im really struggling to do a proper hand calculation for some reason on this really simple frame. none of my methodes seem to solve this one. i need to know what the reaction forces are in the 2 supports at the bottom. Does anyone know something on how to solve this situation? the reaction forces/moments are as you can see already calculated by a simulation.

I hope someone can me help out!

Greetings from the netherlands!

## RE: hand calculation simple frame

## RE: hand calculation simple frame

To figure this out, you need to solve an an indeterminate structure method. A method is the unit force method (read up about this). An outline of the steps ...

1) remove the redundant constraint (the RH x-reaction), solve the structure.

2) calculate the x-displacement to the RH end (where you removed the x-constraint, the end of the RH leg, yes?); call this X. This is going to be tricky as all the elements are bending.

3) then load your determinate structure (what you considered in 1) above) with 1 lbf (1N if you like) in the x-direction, and solve this structure

4) calculate the x-displacement of the RH end under this unit load, call this x.

5) so the RH x-reaction is a load that will return the determinate displacement (from 3) above) to zero, a multiple (= X/x) of your unit load

"Hoffen wir mal, dass alles gut geht !"

General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

## RE: hand calculation simple frame

(8100 * 261.6 / 1030)-----*****-----

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

## RE: hand calculation simple frame

The more "normal" constraint would put a roller under one leg.

"Hoffen wir mal, dass alles gut geht !"

General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

## RE: hand calculation simple frame

## RE: hand calculation simple frame

## RE: hand calculation simple frame

I changed the support at 4 to a roller and it all makes sense now.

The reaction should indeed be (I think) around 2,057kN! The simulation also confirms this after i changed the support at 4.

Thank you all so much for the quick response! Im really sorry that i didnt think of this in the first place.

have a good one!

## RE: hand calculation simple frame

as posted reactions ... 1735*1.03 +510-180 = 2132 (I figured your reactions moment's directions)

"Hoffen wir mal, dass alles gut geht !"

General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.