| An increasing number of companies find that their products pass standard vibration tests but are damaged during transportation. The main reason for this is that the vibration tables used in these tests only move up and down, meaning they lack 5 of the 6 motions that occur in real transportation. Converting a single-axis table to a six-axis table is almost impossible to do. Therefore this research investigated an alternative solution to this problem by adding the second most severe motion, roll. The concept of adding roll to a vertical shaker was to place a rocking platform on the table to act as the new vibration plane. When the table is vibrating, the platform will move both up and down and rock. Theoretically, the rocking motion can be made to match that in a trailer by adjusting two variables of the platform system. The theoretical RMS G could not be verified using test results due to unwanted noise and vibrations produced by the platform flexing and the axle wobbling. However, good agreement between the predicted and experimental rocking natural frequency showed that the concept has some merit. After fixing the problems with the structure of the platform, the next step for this research will be to test actual packages on a trailer and on the platform. |
