Impact behaviour of fibre–metal laminates

Abstract

Abstract Fibre–metal laminates (FMLs) are a new kind of hybrid composites, combining suitable properties of both fibre-reinforced composites and metal alloys, developed over the past three decades. Due to many advantages, such as light weight, high damage tolerance and good fatigue, corrosion and impact properties, FMLs have been effectively used for various applications, particularly in aerospace and aeronautical structures. Several categories of FML composites have been designed and manufactured to tailor specific properties and meet desired performance criteria. The most widely used FMLs are GLARE, ARALL and CARALL, which use glass, aramid and carbon fibres, respectively, reinforced in a polymer matrix along with aluminium as the metal layer. One of the primary loading types experienced by FMLs is different kinds of impact loading. Hence, understanding the characteristics and behaviour of various FMLs under impact will immensely contribute to the design and development of FML structures for use in various impact-related and allied applications. Impact loads produce complex stress–strain responses in FML composites, depending on the nature of the load, such as low-velocity, high-velocity and blast loading. Specifically, dynamic effects due to high strain rates induced and stress-wave propagation cause complex failure mechanisms, involving large-scale deformation, fracture and fragmentation. This chapter deals with the various parameters governing the behaviour of FML composites under different impact load cases. Relevant experimental studies and numerical simulations relating to different types of impacts and the associated responses of FML structures are categorically elaborated. A comparative study has been undertaken, wherever possible, highlighting the superiority of FMLs explicitly over conventional engineering materials. Furthermore, important aspects for optimising FML structures are also presented. This chapter provides a comprehensive summary of the commonly used FML composites and the key parameters affecting their impact properties and performances, including experimental results and numerical modelling. A comparison of properties and performance of various FMLs is also included. The information presented will be highly pertinent towards the development of novel, hybrid materials for applications in extreme, dynamic loading scenarios.