“…The algorithms to carry out this calculation can be classified in two main groups: (a) those based on an uncoupled iterative procedure where equations of motion of bridge and vehicle are solved separately and equilibrium between both subsystems and geometric compatibility conditions are found through an iterative process (Veletsos & Huang, 1970;Green et al, 1995;Hwang & Nowak, 1991;Huang et al, 1992;Chatterjee et al, 1994b;Wang et al, 1996;Yang & Fonder, 1996;Green & Cebon, 1997;Zhu & Law, 2002;Cantero et al, 2009), and (b) those based on the solution of the coupled system, i.e., there is a unique matrix for the system that is formed by eliminating the interaction forces appearing in the equations of motion of bridge and vehicle, and updated at each point in time (Olsson, 1985;Yang & Lin, 1995;Yang & Yau 1997;Henchi et al, 1998;Yang et al, 1999Yang et al, , 2004aKim et al, 2005;Cai et al, 2007;Deng & Cai, 2010;Moghimi & Ronagh, 2008a). The use of Lagrange multipliers can also be found in the solution of VBI problems (Cifuentes, 1989;Baumgärtner, 1999;González et al, 2008a). A step-by-step integration method must be adopted to solve the uncoupled or coupled differential equations of motion of the system.…”