Transport Vibration Laboratory Simulation: On the Necessity of Multiaxis Testing

Nowadays, the packaging industry, like many other sectors, is coping with new demands resulting from financial and environmental constraints. The importance of accurate laboratory simulation of transport vibration as a tool for packaging optimization is therefore increasing, as is highlighted by the International Safe Transit Association testing procedures (ISTA series). In this context, many studies can be found in the literature focusing on the special nature of transport vibrations, analysing the most suitable power spectral density profiles related to route and vehicle characteristics and the best statistical description for acceleration in order to achieve realistic simulation in the laboratory. Most of these works deal only with vertical vibrations because of the of the high energy content such vibrations represent, and only a limited number also analyse longitudinal and transversal acceleration spectra. This paper describes a non-comprehensive set of measurements in real transport situations with the purpose of providing an initial description of the six-degrees-of-freedom vibration produced inside a truck trailer. In addition, the importance of non-vertical random excitation is investigated in the laboratory by means of a multiaxis shaker table used to study the difference in the dynamic response of corrugated containers in stacked shipping units. The results show that the amount of energy neglected using only vertical testing procedures can be significant, and that the packaging bending modes are not excited as they would be in a real transport situation. This demonstrates the necessity of multiaxis testing. Copyright (c) 2010 John Wiley & Sons, Ltd.