- #1

arestes

- 80

- 3

## Homework Statement

Hello. Given the statically determinate truss shown in the image, solve for all forces in the members, in terms of the load P.

## Homework Equations

Equations of equilibrium.

Node analysis.

Section analysis.

## The Attempt at a Solution

I was able to solve it by solving first for the vertical components of the external reactions.

Taking moments at the left support:

I get 7/3 P for the vertical component of the reaction at the support on the right. The vertical reaction at the support on the left is therefore 5/3 P.

There's a relationship between the horizontal components of the supports: they're opposite for equilibrium.

Of course, there are no more equations to solve for the horizontal components of the reactions at both supports, only this relationship. That's why going for a node analysis, there's an unknown I have to drag all the way to the end. This led me to a solution after painstakingly finishing all nodes. I checked that this truss could be solved using an online truss solver. (it's not statically indeterminate. There are 8 members (the ones in the middle don't cross) + 4 unknowns because of the supports=12 unknowns. There are 6 nodes X 2= 12 equations.)

Is there a clever cut to make this problems easier?