1. Layer Arrangement Impact on the Electromechanical Performance of a Five-Layer Multifunctional Smart Sandwich Plate

The reversible effect of piezoelectricity is the ability to generate electrical charge as a result of subjecting to mechanical loads. This active effect is observed in some specific materials called piezoelectric materials. Such active materials are usually employed as attachments or layers in passive structures to provide a self-controlling property with fast response in the resulting smart structures [1]. The application of such active materials mainly relies on their passive structures. In the design of aerostructures, weight and strength are two key points which can be addressed using sandwich structures as they generally contain a thick lightweight core for stabilizing the structures and two thin stiff faces to provide structural strength [2–4]. In this regard, attaching thin layers made of polymer base nanocomposites onto the faces of polymeric porous cores results in multifunctional sandwich structures [5]. Moreover, the use of such passive structures as the host of piezoceramic attachments reduces failure risks due to the brittle structure of piezoceramics. Depending on the application, a wide range of nanofillers with astonishing thermomechanical properties have been proposed and utilized in nanocomposites. Among them, the extraordinary nanofillers of graphene and carbon nanotubes (CNTs) have aroused the interest of researchers in both academia and industry [6–8]. Although there are different parameters in the electromechanical design of five-layer multifunctional smart sandwich plates (5LMSSPs), protecting brittle layers of piezoceramic is also an important issue. Changing the location of piezoceramic layers from faces to middle layers (i.e. between porous core and nanocomposite faces) provides protecting layers. This change in layer arrangements can affect both the mechanical and electrical response of such structures.