Torsional Vibration Apparatus

This bench top mounted unit is used to study torsion and torsional vibration in experiments. The apparatus is constructed around a profiled aluminium base with leveling feet, onto which is mounted 4 vertical chuck pillars. Each pillar contains a central shaft running in precision bearings with a chuck at one end which grips a torsion specimen. Each chuck also contains a large disc of varying mass and inertia. With these chucks it is possible to assemble a torsion specimen with up to 3 masses.

Vibrations are transmitted into the torsion specimen by means of an exciter, which is electronically speed controlled from the main control unit. To change the end conditions of the apparatus a fifth chuck houses a chuck which rigidly clamps the end of the torsion specimen to achieve a fixed end. Also supplied with the apparatus is a manual torsion arrangement, which allows a known angular twist to be applied to the specimen. A cord is wrapped around one of the large discs and a load is applied via a hanger and weights set. The angle of twist for incremental loading is recorded and the modulus of rigidity can be calculated.