“…There are plenty of studies on free vibration behaviour and characteristics of uniform cross-section homogeneous and composite intact structures (Erdurcan and Cunedioğlu, 2020; Jiang et al, 2018; Kim and Shin, 2008; Mohanty et al, 2013; Zahedinejad, 2016; Zhang et al, 2020) and cracked structures (Cunedioglu, 2015; Ferezqi et al, 2010; Gayen and Chakraborty, 2016; Gayen et al, 2017a, 2017b, 2018; Han et al, 2020; Kisa and Brandon, 2000; Kisa et al, 1998; Liu et al, 2017; Papadopoulos, 2004; Papadopoulos and Dimarogonas, 1987; Shabani and Cunedioglu, 2019).…”