Parameter estimation in active plate structures using gradient optimisation and neural networks

Identification of material properties of composite materials using nondestructive vibrational evaluation approaches: A review

“…As proven in [133], the simulations for thick multilayered composite plate model with order of third and above, applying PSDT are well-correlated with those from third-order layer-wised plate theory as well as the computational effort was much reduced. Araujo and co-workers [113,114] adopted finite element method to construct an active plate model with surface-bonded piezoelectric patches, based on a displacement field using third order expansions in the thickness coordinate the in-plane displacements, and a constant transverse displacement. This model allowed the analysis of arbitrary thin and thick plate and shell structures with more accurate results.…”

“…The use of feasible directions method has rooted its reign of recognition in the field of material identification since 1990's for its simplicity in coding and efficiency, in which, penalty functions, active set strategies or quadratic programming subproblems are not involved in the solutions [60,61,113,114,117,141]. It is very useful for problems with objective function or constraint functions that are not defined at infeasible points, for example, in the field of material properties determination for laminated composite plates with surface-bonded piezoelectric patches [113,114,117]. As stated in [117], it must be noted that simultaneous identification of elastic constants, piezoelectric and dielectric coefficients was impractical, thus, separate evaluation of each category was required using the proposed method.…”

“…In the aspect of boundary condition, plates with free-free edges [66,69,70,77,78,83,86,[110][111][112][113][114][115][116][117][118][119][120][121][122][123][124][125][126][127][128]130], simply-supported edges [110] and clamped edges [83,129] are often taken into investigation. Generally, laminated plates are utilized in previous studies [86,110,[112][113][114][117][118][119]. Thickness of plates also plays a cardinal role in deciding the use of appropriate plate theory in finite element modelling.…”

Characterization of Properties and Damage in Piezoelectrics

“…To address the limitations of current characterization methods in determining elastic and piezoelectric constants (Araújo et al (2009);Araújo et al (2002)) propose a finite element model-based, associated to gradient optimisation-based inverse problem algorithm using vibration data to carry out the identification of electromechanical properties in composite plate specimens with surface bonded piezoelectric patches or layers. This method has been later refined with neural networks to aid the inversion algorithms Araújo et al (2006). The problem of how to define which measurements and how to measure in order to minimize the uncertainties of material parameters given the unavoidable measurement noise has recently been addressed by Lahmer et al (2010).…”

“…A similar cost functional was used by Ruíz et al (2004a;, which was minimized using genetic algorithms. On the other hand, Araújo et al (2006); Araújo et al (2002) proposed an inverse problem to obtain the constitutive properties of composite plate specimens with surface bonded piezoelectric patches or layers, where the cost functional was the difference between the experimental and FEM-predicted eigen-frequencies and its minimization was carried out using two strategies: a gradient-based method, and neural networks. A genetic algorithm was applied by Chou & Ghaboussi (2001) and Mares & Surace (1996) to solve the IP in elastic structures.…”