Dynamic compressive behavior of foamed polyethylene film

• Main Authors: Tateyama, Kohei, Yamada, Hiroyuki, Ogasawara, Nagahisa, Okui, Ryo, Ogawa, Kinya
• Format: Conference Proceeding
• Language: English
• Subjects: Compressive properties; Computed tomography; Construction materials; Deformation mechanisms; Dependence; Drop tests; Dynamic mechanical properties; Film thickness; High strain rate; Mechanical properties; Plastic foam; Polyethylene films; Static deformation; Strain rate; Strain rate sensitivity; Yield strength
• ISSN: 2100-014X; 2101-6275; 2100-014X
• DOI: 10.1051/epjconf/20159401038

The foamed film as the shock absorption material has attracted much attention because it is thin (100 μm ∼ 400 μm) and has a closed cell structure. However, the dynamic mechanical properties have not been reported in the foamed film. The purpose of this study is to elucidate the compressive behavior of the foamed polyethylene film at the wide strain rate range. First, the new compressive test apparatus for the dynamic strain rate, the drop-weight testing machine with opposed load cell, was developed, which can be also evaluated the dynamic stress equilibrium of the specimen. It is confirmed that the compressive flow stress increased with increasing the strain rate, regardless of the film thickness. The foamed polyethylene film has the high strain rate sensitivity in the quasi-static deformation. On the other hand, there is almost no change of the strain rate sensitivity in the dynamic and the impact deformation. In order to investigate the mechanism of strain rate dependence, the foamed polyethylene film was observed by X-ray computed tomography scanner before and after compressive test. The fracture of the closed cell only occurred in the quasi-static deformation. It was clarified that the strain rate sensitivity of the foamed film depends strongly on that of the construction material, polyethylene.