Transport Worthiness Test / Vibration Test.
Summary : Generally a product is placed in its primary packaging and then in a secondary packaging before being dispatched in truck or similar transport vehicle. Sometimes the transportation is also through Rail or Air. In order for the product to reach the consumer intact it has to be designed to withstand the hazards of a road / rail / air journey.
The most common failures are seen as breakages, leakages, scratches, etc.
Vibration tests are generally done on filled shipping containers. Such tests may be used to assess the performance of a container, with its interior packing and means of closure, both in terms of its strength and of the protection it provides its contents when it is subjected to vibration such as it experiences in transportation. These procedures are suitable for testing containers of any form, material, kind, design of interior packing, means of closure, and any size and weight. They are not intended for determining the response of products to vibration for product design purposes, nor are they intended for tests of products in their operational configuration as other more suitable procedures are available for these purposes.
Test Method :
As per ASTM D 999, the package is placed on a vibration table which is made to move up / down and cause a displacement of 1 inch. The speed is gradually increased till the package starts bouncing off the platform surface by around 1.6mm. The test is then continued at this speed for the remaining test period as determined by the user (usually 1 or 2 hours).
A study conducted on Indian Road Conditions concluded that for every 1 km of road, there are about 7 pits of 1 inch or more depth.
Which means that in order to simulate a journey of 1000 km, we would need to subject the package to 7000 vibrations of 1 inch displacement. Based on the current test speed, you can calculate the time required for the test. Vibration Test Machines are usually equipped with a Vibration Counter or Digital Timer or Both.
Transport Data Loggers are portable, battery operated devices which can sense and record vibration. You can use this data to compare real life vibrations (in a truck) and those that are being generated by a Vibration Test Machine. Some data loggers even have additional recordable parameters such as Temperature, Humidity, and Atmospheric Pressure. This can help you understand the transit conditions even better.
Test Standard : ASTM D999