Description

The truss hub members are made of tubular aluminium with an outside diameter of 10.0mm and a wall thickness of 1.0mm.

The truss members are pre-cut to the following lengths:

• 80.5mm
• 176.5mm
• 198mm
• 207.5mm

All members are clearance-drilled at each end to allow the detent pins to engage freely in the joint hub. The machined joint hubs are drilled with a circular pattern of holes for the detent pin connections. In each joint hub there are 10 holes so that scale divisions of 30° and 45° are possible.

The smallest angle spacing between two members is 30°, this enables up to 10 members to engage on one truss hub. One member on each truss hub must be rigidly located in the joint hub via a drilled location hole. This is necessary in order to obtain a rigid, statically certain truss, without this, the joint hub would itself become an additional member of the truss.

Place the two sealed bearings, one either side of the free joint hub, connecting them using one Ø10 x 40mm long detent pin. This allows the joint hub to move along the bearing side mounting block.

The external stresses are applied to the truss via the load cell assembly. The experiment frame deforms under the force and the deflection of the frame can be measured. In order to be able to generate a force the respective test truss must first be pre-stressed. Play in the truss hubs is eliminated in order to achieve this. Pre-stressing is completed by applying a small force via the load cell assembly to remove any slack in the experiment frame.

The load cell assembly can be attached to the frame at any truss hub. It enables tensile and pressure forces of up to 400N to be applied and measured.