* Corresponding author. E-mail addresses: hamed.saghafi2@unibo.it (H. Saghafi) © 2015 Growing Science Ltd. All rights reserved. doi: 10.5267/j.esm.2014.12.003 Engineering Solid Mechanics 3 (2015) 21-26 Contents lists available at GrowingScience Engineering Solid Mechanics homepage: www.GrowingScience.com/esm Improvement the impact damage resistance of composite materials by interleaving Polycaprolactone nanofibers H. Saghafi * , T. Brugo, G. Minak, and A. Zucchelli Department of Industrial Engineering (DIN), Alma Mater Studiorum, Universita` di Bologna, viale Risorgimento 2, 40136 Bologna, Italy A R T I C L E I N F O A B S T R A C T Article history: Received September 6, 2014 Accepted 22 November 2014 Available online 23 December 2014 In this study, the impact response of glass/epoxy laminates interleaved by Polycaprolactone (PCL) nanofibers is considered. PCL is a thermoplastic polymer, which is a good choice for toughening epoxy-based composite. The impact tests were conducted on curved laminates and under 24 and 36J. The results showed that the effect of interleaving on impact parameters such as maximum load is negligible, but on the other hand could decrease damaged area significantly. By inserting 30m of PCL nanofibers between each layer of laminate the damaged area decreased about 27%. © 2015 Growing Science Ltd. All rights reserved. Keywords: Nanofibers Electrospinning Impact loading Interleaving 1. Introduction Compared with more traditional materials such as metals and ceramics, fiber reinforced composites have several specific features such as high stiffness and strength to weight ratio. The most common failure mode of this high performance laminated material is delamination as a consequence of low velocity impact. Insufficient fracture toughness and delamination are the main issues affecting the long- term reliability of thermosetting matrix composites. Matrix-toughening seems to be one of the recommended methods, in which interleaf layers of toughened materials are inserted into the middle plies of the composites. Generally, thermoplastic particles and films have been used as common toughened layers (Sohn et al., 2000). However, difficulty of particle preparation due to high toughness of thermoplastic and high thickness of films due to high viscosity of thermoplastic, have limited their uses in industrial applications. Recently, nanofibers reinforcing was known as a more useful technique instead of particles or films reinforcing to enhance the mechanical properties of composite because of their very small diameters.