Drop and Impact Simulation Technology

Products are subject to various types of vibrations and shocks when they are shipped from the factory. At Fuji Xerox, we are striving to improve the quality of our product transporting methods in order to protect products from impacts and deliver them to customers without any problems occurring.
As shown in Fig. 1, up until now, in order to improve the way we transported a product, it was necessary to repeat the processes of conducting vibration and drop tests using prototypes of the product and packaging, identifying the problems, and redesigning the prototypes. This method, however, took a long time, since tests of the improved product and packaging could not be conducted until their prototypes were made. Also, since only a limited number of prototypes could be made, it was not possible to test for all of the various possible transportation environments sufficiently. To address these issues, Fuji Xerox has changed from a quality improvement process that uses prototypes to one that uses simulations.

Fig. 1: Process of improving product transportation quality

In order to use simulations to improve the quality of our product transportation, it is necessary to understand the properties of packaging materials under the conditions present during transportation. For example, to conduct a drop and impact simulation, the properties of the materials when in a state of acceleration, such as during a drop and impact test, must be input into the simulation model. However, material properties under such conditions are not listed in materials handbooks or catalogs. Therefore, Fuji Xerox measured the dynamic material properties of materials frequently used for packaging under various conditions and compiled a library of those results.

Fig. 2: Nominal stress-strain curves of foamed polystyrene
(measured under conditions similar to those during a drop and impact test)

Furthermore, in order to improve the accuracy of the simulations, the simulation models must be optimized to ensure that the results of drop tests conducted using prototypes and the results of simulations do not differ greatly. We use quality engineering methods to calculate the signal-to-noise (SN) ratio and sensitivity of each parameter of the simulation model in order to select the optimal parameters.

Fig. 3: Acceleration profile of a simulation before and after simulation model optimization
(parameters were adjusted based on cause and effect analysis of simulation parameters)

In recent years, there is also a need to reduce the amount of packaging materials used in order to become more environmentally-friendly. Fuji Xerox is working to achieve both improved product transportation quality and reduced packaging by evaluating new packaging materials and also creating simulation models for packaging that combines various materials.