1J40.80 - Truss Bridges
Demonstrate the strength and rigidity of various truss designs under a heavy load.
Obtain one or all seven bass wood truss bridges from the demo lab. Their lead-shot filled toy ambulance (1Kg), and deflection stand.
Place the bridge down so that your audience has a clear view of the truss design and deflection of the bridge under load. Carefully place the deflection stand on either the left or right side of the middle. Take note of its angle, typically 0 not under load. Gently place the toy ambulance on the truss bridge, and slowly rolling it to the middle to show an increase of deflection. Take note of the change of angle on the deflection stand. Varies from 0-10 degrees depending on the truss design.
Dividing the cantilever of the brige in half reduces the angle of deflection most.