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Numerical analysis of piezoelectric active repair in the presence of frictional contact conditions.

Alaimo A, Milazzo A, Orlando C, Messineo A - Sensors (Basel) (2013)

Bottom Line: In this paper, Boundary Element (BE) analyses performed on delaminated composite structures repaired by active piezoelectric patches are presented.A two-dimensional boundary integral formulation for piezoelectric solids based on the multi-domain technique to model the composite host damaged structures and the bonded piezoelectric patches is employed.The effect of the adhesive between the plies of piezoelectric bimorph devices on the electromechanical response is first pointed out for both sensing and actuating behavior.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Engineering and Architecture, University of Enna Kore, Cittadella Universitaria 94100, Enna, Italy. andrea.alaimo@unikore.it

ABSTRACT
The increasing development of smart materials, such as piezoelectric and shape memory alloys, has opened new opportunities for improving repair techniques. Particularly, active repairs, based on the converse piezoelectric effect, can increase the life of a structure by reducing the crack opening. A deep characterization of the electromechanical behavior of delaminated composite structures, actively repaired by piezoelectric patches, can be achieved by considering the adhesive layer between the host structure and the repair and by taking into account the frictional contact between the crack surfaces. In this paper, Boundary Element (BE) analyses performed on delaminated composite structures repaired by active piezoelectric patches are presented. A two-dimensional boundary integral formulation for piezoelectric solids based on the multi-domain technique to model the composite host damaged structures and the bonded piezoelectric patches is employed. An interface spring model is also implemented to take into account the finite stiffness of the bonding layers and to model the frictional contact between the delamination surfaces, by means of an iterative procedure. The effect of the adhesive between the plies of piezoelectric bimorph devices on the electromechanical response is first pointed out for both sensing and actuating behavior. Then, the effect of the frictional contact condition on the fracture mechanics behavior of actively repaired delaminated composite structures is investigated.

No MeSH data available.


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Effect of the friction coefficient on the fracture parameters.
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f11-sensors-13-04390: Effect of the friction coefficient on the fracture parameters.

Mentions: Figure 11 shows the total energy release rate distribution versus the applied voltage, V, obtained for different values of the friction coefficient, μ. The energy release rate is plotted in dimensionless units by dividing Gt to G0, G0 being the total energy release rate characterizing the fracture mechanics behavior of the un-repaired structure. It is worth noting that the computed G0 = 1.43 × 10-4 MPam agrees very well with that found by Narayan et al. [25] through a finite element analysis. From Figure 11, it can be observed that the repair condition for the three different contact configurations analyzed, corresponding to the minimum value of the total energy release rate, is reached at the same value of the repairing voltage, Vr = 1.850 V. Thus, it can be firstly concluded that the different frictional contact conditions do not have valuable influence on the repairing voltage value. On the other hand, for a given applied voltage, V < Vr, the effect of the frictional contact between the crack surfaces is to improve the repair performance of the active patch till the minimum value of GT is obtained. The analysis of the post-repair condition, corresponding to V > Vr, evidences the same behavior as for V < Vr, with the only exception inside the interval 1, 900 < V < 2, 200, where the repair performances of the friction contact configuration are worse than the frictionless one. The graph of Figure 11 shows that, once the repair condition is reached, the phase angle, ψ, gets its minimum value. Moreover, the effect of friction on the mode mix is to reduce ψ and, consequently, the amount of the mode II of fracture with respect to mode I.


Numerical analysis of piezoelectric active repair in the presence of frictional contact conditions.

Alaimo A, Milazzo A, Orlando C, Messineo A - Sensors (Basel) (2013)

Effect of the friction coefficient on the fracture parameters.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3673090&req=5

f11-sensors-13-04390: Effect of the friction coefficient on the fracture parameters.
Mentions: Figure 11 shows the total energy release rate distribution versus the applied voltage, V, obtained for different values of the friction coefficient, μ. The energy release rate is plotted in dimensionless units by dividing Gt to G0, G0 being the total energy release rate characterizing the fracture mechanics behavior of the un-repaired structure. It is worth noting that the computed G0 = 1.43 × 10-4 MPam agrees very well with that found by Narayan et al. [25] through a finite element analysis. From Figure 11, it can be observed that the repair condition for the three different contact configurations analyzed, corresponding to the minimum value of the total energy release rate, is reached at the same value of the repairing voltage, Vr = 1.850 V. Thus, it can be firstly concluded that the different frictional contact conditions do not have valuable influence on the repairing voltage value. On the other hand, for a given applied voltage, V < Vr, the effect of the frictional contact between the crack surfaces is to improve the repair performance of the active patch till the minimum value of GT is obtained. The analysis of the post-repair condition, corresponding to V > Vr, evidences the same behavior as for V < Vr, with the only exception inside the interval 1, 900 < V < 2, 200, where the repair performances of the friction contact configuration are worse than the frictionless one. The graph of Figure 11 shows that, once the repair condition is reached, the phase angle, ψ, gets its minimum value. Moreover, the effect of friction on the mode mix is to reduce ψ and, consequently, the amount of the mode II of fracture with respect to mode I.

Bottom Line: In this paper, Boundary Element (BE) analyses performed on delaminated composite structures repaired by active piezoelectric patches are presented.A two-dimensional boundary integral formulation for piezoelectric solids based on the multi-domain technique to model the composite host damaged structures and the bonded piezoelectric patches is employed.The effect of the adhesive between the plies of piezoelectric bimorph devices on the electromechanical response is first pointed out for both sensing and actuating behavior.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Engineering and Architecture, University of Enna Kore, Cittadella Universitaria 94100, Enna, Italy. andrea.alaimo@unikore.it

ABSTRACT
The increasing development of smart materials, such as piezoelectric and shape memory alloys, has opened new opportunities for improving repair techniques. Particularly, active repairs, based on the converse piezoelectric effect, can increase the life of a structure by reducing the crack opening. A deep characterization of the electromechanical behavior of delaminated composite structures, actively repaired by piezoelectric patches, can be achieved by considering the adhesive layer between the host structure and the repair and by taking into account the frictional contact between the crack surfaces. In this paper, Boundary Element (BE) analyses performed on delaminated composite structures repaired by active piezoelectric patches are presented. A two-dimensional boundary integral formulation for piezoelectric solids based on the multi-domain technique to model the composite host damaged structures and the bonded piezoelectric patches is employed. An interface spring model is also implemented to take into account the finite stiffness of the bonding layers and to model the frictional contact between the delamination surfaces, by means of an iterative procedure. The effect of the adhesive between the plies of piezoelectric bimorph devices on the electromechanical response is first pointed out for both sensing and actuating behavior. Then, the effect of the frictional contact condition on the fracture mechanics behavior of actively repaired delaminated composite structures is investigated.

No MeSH data available.


Related in: MedlinePlus