Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.


Proper cushioning to prevent product damage and over-packaging must consider the mechanical-shock fragility of the product. Furthermore, improved cushioning design can be achieved by performing stochastic cushioning design using mechanical-shock fragility statistics and transport hazard statistics. However, many samples are required to obtain mechanical-shock fragility statistics from standard testing comprising critical velocity change tests and critical-acceleration tests (the “conventional method”). In many cases, the required number of samples cannot be prepared. Thus, this research is designed to develop testing methods requiring half the number of samples of the conventional method. Thus far, "test method with one sample" has been developed by improving the standard testing method required two samples. Hence, we propose a new statistical method (the “proposed method”) that obtains statistics by multi-sample testing using a test method with one sample. The proposed method is one in which the shock of a single velocity change (the “test velocity change”) is given by increasing the acceleration in a step-wise fashion, and the results indicate the failure rate at the test velocity change and provide the critical-acceleration statistics. In these experiments, the critical-acceleration statistics for a test velocity change larger than the critical velocity change were equivalent to those obtained from the conventional method. The accuracy of the failure rate at test velocity changes was clarified. Moreover, examples are provided showing the results when the proposed method is applied to simple stochastic cushioning design.