Methode van doorsneden: Probleemoplossing II

Consider an arbitrary truss structure comprising of diagonal, vertical, and horizontal members fixed to the wall.

The method of sections can be used to calculate the force acting on members CB, GB and GH.

Here, the loads and the lengths of the horizontal and vertical members are the known parameters.

A cut is made along a plane intersecting CB, GB and GH members and a free-body diagram of the right side section is drawn.

The moment equilibrium equation about point G gives the force along CB. The positive sign indicates tension in the member. 

Now, F_GB can be expressed using a slope triangle in BCG, while F_GH can be expressed using a slope triangle in CEG.

Considering the summation of vertical and horizontal forces, the force equilibrium equations can be written.

The value of F_CB is substituted.  The force equilibrium equations are solved simultaneously to obtain the force along GH and GB members.

The negative sign of FGH indicates that the force is compressive, while the positive sign for F_GB indicates the tensile force.