Energy Dissipation Capacity in MWCNTs Reinforced Metal Matrix Nanocomposites: An Overview of Experimental Procedure

Adsorption of vibration energy by mechanical damping is a significant problem in many engineering designs. High damping materials are used to reduce vibration in aircraft and other machinery. The benefits of damping treatment are advanced durability, reliability and service life of components, reductions in weight, noise and costs (Chung, 2001). By invoking the properties of nanostructures it may be possible to control the shock wave propagation in the material and thus, significantly enhance the impact energy dissipation; however, only limited research papers concern about damping composite structures and shock resistant of nanomaterials. If one goes to the nanoscale, the damping levels/dynamics of structures are mostly unknown and require extensive investigations. This chapter traces the experimental and analytical investigation methods for damping capacity and its application to nanocomposites. A couple of works were published about investigation of damping capacity in different material (Koizumi et al., 2003; Gu et al., 2004; Srikanth & Gupta, 2005; Zhang et al, 2005; Botelhoa, 2006; Kireitseu et al., 2007; Yadollahpour et al., 2009). These works were summarized in Table 1. The first part of this chapter deals with an overview of experimental procedures for investigation of energy dissipation capacity in materials. Carbon nanotubes (CNTs) have superior mechanical properties with an elastic modulus up to 1 TPa and a tensile strength up to 150 GPa and, as well as excellent thermal stability and electrical conductivity (Ci et al., 2006). Their exceptional mechanical properties make CNTs ideal candidates as reinforcements in composite materials to increase both stiffness and strength, while contributing to weight savings (Esawi & Morsi, 2007). Larger portion of the researches have been focused on the development of CNT reinforced polymer, ceramic based composites, and only a few studies have been concerned with the manufacture of CNT reinforced metal matrix composite (George et al., 2005;Chunfeng et al., 2007). It has been confirmed that the mechanical properties of metal matrix composites were improved, when an appropriate amount of nanotubes were added (Deng et al., 2007a). Beside considerable reinforcement effect of CNTs, fabrication of MMCs with nanostructured matrices may also provide excessive properties due to their greater mechanical characteristics compared to coarse-grained counterparts.