Article 28 -Dynamic Test of Moving Walk Pallet – Torsional Test
Introduction to Dynamic Test of Moving Walk Pallet – Torsional Test
The pallet dynamic test is divided into two different types: Load and Torsional. The Dynamic Torsional Test of Moving Walk Pallet can be applied in different ways and one of them is state below:
A torsional test is only required if the pallets have rollers.
For the pallet torsional test, we must apply a continuous sinusoidal pulsating load of 500 - 3000 N at a frequency of 5-20 Hz for a minimum of 5x106 cycles to the tread surface center on a steel plate (0.20 m x 0.30 m & at least 25 mm thick).Test must be applied to pallet with rollers (not rotating), axles and stub shafts (if existing) together in horizontal position and at maximum inclination and the pallet is supported and fixed via the step chains. To minimize the effect of the pallet rollers on the result of the test, we must replace them with steel rollers of the same dimensions. We must take out one of the pallet rollers (or make it unsupported) and in order to prevent lifting off of the opposite pallet roller we must use a locking clamp with the distance of less than 0.2mm on the pallet chain roller.
During the test, the removed roller side must move downward less than 4mm.
No cracks or issues must be seen as a result of the test. Permanent deformation must be less than 4 mm on the tread surface and pallet and its components including all inserts/ fixings must stay secure and attached firmly after the test.
Any damaged roller must be replaced during the test as required.
The 4 mm displacement is acceptable when the distance of the pallet roller center and the pallet chain roller center is 400mm and in other cases the ratio must be maintained.