Though many inverse problems in structural mechanics are formulated on the continuous setting, and evaluated on the discrete setting based on FEM or boundary element methods (BEM) (Bonnet and Constantinescu, 2005), both of the above inverse problem formulations are discrete formulations (Mroz and Garstecki, 2005) or based on discrete linear model equations (Hansen and O’Leary, 1993), for example, finite element models or methods (FEM) (Mottershead and Friswell, 1993; Friswell and Mottershead, 1995; Gladwelly, 1997; Avitabile,2000; Chock and Kapania, 2003; Chock and Kapania, 2004; Maincon, 2004a; Maincon, 2004b; Maree and Maincon, 2004; Barnardo and Maincon, 2004; Trivailo et al., 2004; Mrozand Garstecki, 2005).