presents a mathematical framework for the wave propagation problem of small-scale nanobeams and nanoplates manufactured from various materials, including functionally graded composites, smart piezoelectric materials, smart magneto-electro-elastic materials, smart magnetostrictive materials, and porous materials. In this book, both classical and refined higher-order shear deformation beam and plate hypotheses are employed to formulate the wave propagation problem using the well-known Hamilton’s principle. Additionally, the influences of small-scale nanobeams on the mechanical behaviors of nanostructures are covered using both nonlocal elasticity and nonlocal strain gradient elasticity theories. Impacts of various terms, such as elastic springs of elastic foundation, damping coefficient of viscoelastic substrate, different types of temperature change, applied electric voltage and magnetic potential, and intensity of an external magnetic field on the dispersion curves of nanostructures, are included in the framework of numerous examples.