• Product: External hard drive with packaged with cushioning material
• Analysis Goal : Evaluation of cushioning material to absorb the impact of the falling hard drive
Here, an external hard drive protected by cushioning material and a drop test machine were modeled using RecurDyn in accordance with the drop test, JIS standard Z0200 and Z0202.
The analysis evaluated the performance of the Styrofoam cushioning material. The cushioning material was modeled as an FFlex body and its stress and the acceleration of hard drives were calculated. The predicted acceleration of the hard drive matched the results of an actual drop test well.
① Import CAD data of hard drive and cushioning materials (Styrofoam, Corrugated box).
② Create FFlex body for cushioning material and define Geo contact between hard drive and cushioning material.
③ Create RecurDyn model of drop test machine.
④ Analyze model in accordance with JIS standard test conditions.
Key Technologies for Analysis
• MFBD model for evaluation of cushioning material to protect hard drive
• Contact between cushioning material flexible body, hard drive, and the corrugated box
• Contact parameter identification to reproduce the acceleration of hard drives during drop test
• Difficulty evaluating effect of cushioning material on the acceleration in the hard drive using physical drop test
• Difficulty in determining packing configurations that cause damage to the cushioning material
• Impossible to measure acceleration at arbitrary locations in the hard drive
• High expense and time required to design, perform, and analyze physical drop tests
• Geo contacts between hard drive and cushion or corrugated box (Contact stiffness was estimated from cushioning material data)
• Cushioning material modeled using FFlex body to evaluate the stress and deformation
• Drop test machine included in analysis model
• MFBD model accurately reproduced measured physical drop test accelerations.
• Though impossible with a physical drop test, using FFlex, the contact state of the cushioning material became clear.
• Theoretical analysis of behavior of cushioning material becomes much more sophisticated. Expect a significant reduction in labor to design hard disk cushioning.
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