Damage behavior of fiber reinforced composite plates subjected to drop weight impacts Ramin Hosseinzadeh a , Mahmood Mehrdad Shokrieh b, * , Larry Lessard c a Mechanical Engineering Department, Sharif University of Technology, Tehran 11365-8639, Iran b Composites Research Laboratory, Mechanical Engineering Department, Iran University of Science and Technology, Tehran 16844, Iran c Mechanical Engineering Department, McGill University, Montreal, Canada H3A 2K6 Received 18 October 2004; received in revised form 21 May 2005; accepted 30 May 2005 Available online 26 July 2005 Abstract Fiber reinforced materials are widely used in many industrial structures including automotive, aviation, and civil due to their lower weights compared to metal structures. Full-composite body structures, especially in automotive and aviation applications, are becoming a proper replacement for current metal ones. For this reason, damage of such structures subjected to impact is a cru- cial case study in current research. The typical types of damages are mainly caused during production, repair, maintenance, or by particle crashes during function, and collisions between different structures. In this paper, four different fiber reinforced composite plates are studied after being impacted by a standard drop weight with different impact energies and moments. The damage zones are studied by ultra-sonic non-destructive inspection. Carbon fiber reinforced composite plates show the best structural behavior under low velocity impacts meanwhile carbon/glass fiber reinforced (hybrid) plates show suitable behavior under high impact energy. Finally, all the plates are modeled using ANSYS LS DYNA V6.1 under similar conditions to those of the tests. The damage zone shapes derived from software modeling do not show very good coincidence with those resulting from the tests. However, the software is able to predict the threshold of damage as it is verified well by test results. Ó 2005 Elsevier Ltd. All rights reserved. Keywords: Fiber reinforced composite; Plate; Impact; Aviation; Automotive Carbon/Epoxy; Glass/Epoxy; Carbon/Glass/Epoxy; Hybrid 1. Introduction Fiber reinforced body vehicles are being used in the aviation and automotive industry due to their advanta- geous characteristics, mainly weight reduction, which is one of the most important design parameters for such applications. Due to completely different material speci- fications between metals and composites, the impact behavior of structures made by these materials differs inherently. Metals show visible damage caused by impact mainly on the surface of structures, while damage is hid- den inside composite structure especially when subjected to low velocity impact [1]. This invisible form may cause serious decrease in material strength [1], which can be created during production, repair, maintenance, and small particle crashes to the composite body [2]. Ross and Sierakowski [3] studied the effects of impacts exerted by conical head impactors and observed delamina- tion in glass epoxy plates by using a powerful light source. Clarck [4] developed a model for delamination of different fiber reinforced plates and showed that the delamination is in the form of stretched or almond shape. Evans and Mas- ters [5] showed how toughened matrix could develop im- pact characteristics of epoxy composites while Zhou and Greaves [6] studied damage resistance and tolerance of glass fiber reinforced plates with different thickness. 0266-3538/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.compscitech.2005.05.025 * Corresponding author. Tel./fax: +98 217 491 206. E-mail addresses: rhosseinzadeh@alum.sharif.edu (R. Hosseinza- deh), Shokrieh@iust.ac.ir (M.M. Shokrieh). Composites Science and Technology 66 (2006) 61–68 COMPOSITES SCIENCE AND TECHNOLOGY www.elsevier.com/locate/compscitech