Vibration tests of packaged products are conducted before distribution in order to prevent troubles in markets. However, as these troubles sometimes occur, it can not necessarily be said that test conditions are represented real environment. Various test methods have been proposed in order to derive test conditions equivalent to real environment. However, these methods have not taken into account three-dimensional motions of products under vibration. If the method with three-dimensional analysis is constructed, it is considered that more proper tests can be conducted, and contributes to reduce troubles in markets. Therefore, in order to examine three-dimensional motions of products, vibration experiments of packaged products under vertical vibration have been conducted. As a result, it has been confirmed that products in a package move three-dimensionally in spite of only vertical vibration, and that fatigue due to the vibration is accumulated besides the vibration direction. By these, it has been clarified that it is necessary to take into account three-dimensional motions of products under vibration in order to derive test conditions equivalent to real environment.

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