ASTM D5487 provides a standardized method for simulating the drop of loaded shipping containers. The purpose of this method is to test the robustness and resilience of both the containers and their interior packaging materials, which often face various hazards during handling, transportation, and storage.
Shock and impact are among the most significant of these hazards. Conventional free-fall drop testing, which is simple to perform, may not accurately represent the stresses experienced, particularly when the drop is not perpendicular to the dropping surface. As observed in real-world scenarios, even a slight deviation from perpendicularity can result in an 8% reduction in acceleration in the test specimen due to the dispersal of impact energy across multiple axes.
To overcome the limitations of free-fall testing, ASTM D5487 recommends the use of shock machines, which provide controlled shock inputs that more effectively evaluate the ability of shipping containers, interior packaging materials, and contents to withstand shocks. This approach has proven effective, especially when testing package systems with critical elements, as long as the frequency of the shock pulse is at least three times that of the package system's natural frequency.
However, the method also recognizes the significant influence that package fixturing on the shock test machine can have on the results. Any pressure exerted by the fixturing should be minimal, especially with materials like corrugated containers. If low-acceleration, long-duration responses are expected, the test method suggests that the package can be tested without direct fixation to the table to avoid potential influence on the response of the packaged item.
The test method covers procedures for using shock machines to replicate the effects of vertical drops of loaded shipping containers, cylindrical containers, bags, and sacks. It provides guidance on determining the appropriate shock pulse duration and frequency based on the package system's natural frequency, ensuring that the simulations yield meaningful and reliable results. This standard test method is critical to ensure that containers can adequately protect their contents during transportation and handling.