Frames: Problem Solving II

Consider a hydraulic hoist supporting a load.

Assuming a simplified schematic representation of this frame structure, what force is acting on BD and BF members, provided the member dimensions and the weight of the load are known?

Here, BF and BD are two force members, while EFG and EDC are multi-force members.

A free-body diagram for the member EFG indicating all the forces is drawn.

The vertical and horizontal components of the force F_BF  can be expressed using a slope triangle.

The moment equilibrium condition at joint E gives the force F _BF .

Then, applying the horizontal force equilibrium condition at joint E, the horizontal reaction force at E is evaluated.

Similarly, the vertical force equilibrium condition gives the vertical reaction force at joint E.

Now, drawing a free-body diagram for the member EDC, the components of the force along BD can be expressed using another slope triangle.

Applying the moment equilibrium condition at point C, the force F _BD  is calculated.