Impact Performance Evaluation of Thermoplastic Sandwich Structures with Circular-Cell Cores and Commingled Randomly Distributed Long Glass Fiber Reinforced PP Sheet Skins

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Elbhnasawı M., Motorcu A. R., Yazıcı M.

International Connect & Expo on Materials Science and Engineering (MATERIALSCONNECT2025), Rome, İtalya, 28 - 30 Nisan 2025, ss.27-28, (Özet Bildiri)

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Rome
  • Basıldığı Ülke: İtalya
  • Sayfa Sayıları: ss.27-28
  • Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet

Özet

Sandwich structures are widely used in engineering applications due to their high specific bending stiffness and excellent impact resistance. This study developed a novel thermoplastic sandwich panel using an extruded circular-cell polypropylene (PP) core and surface skins fabricated from commingled polypropylene/glass (PP/Glass) fiber veils. The commingled PP/Glass mats used for the skin layers were randomly oriented long fiber reinforced thermoplastic (LFT) composites with a nominal thickness of 0.3 mm and an areal weight of 1800 gsm. The skin plates were manufactured via hot compression molding at 185 °C under a pressure of 300 kN, ensuring optimal impregnation and consolidation.

The resulting thermoplastic composite plates were subsequently bonded to the circular-cell PP cores using a thermal press bonding technique, producing lightweight and structurally efficient sandwich composites. Mechanical characterization of the sandwich panels included dynamic three-point bending tests and low-velocity impact penetration tests to evaluate their flexural behavior and energy absorption capacity.

Preliminary results indicate that integrating circular-cell cores with high-stiffness commingled thermoplastic skins significantly enhances the sandwich structures' bending resistance and impact penetration performance. This material system shows strong potential for lightweight structural applications in automotive, aerospace, and protective equipment industries, where high strength-to-weight ratios and recyclability are critical.

The study advances sustainable thermoplastic sandwich technologies by leveraging recyclable PP-based materials and scalable manufacturing methods. The results show that 2D randomly distributed composite skins increased impact penetration resistivity of the circular cell PP core by around 30% due to long-fiber reinforcement and 2D random orientation. The bending rigidity of the circular cells' PP core increased by more than 40% due to composite skins, with negligible weight increase.