Smart Composite Sandwich Structures for Future Aerospace Application -Damage Detection and Suppression-: a Review

Abstract

Sandwich structures with advanced composite facesheets are attracting much attention as a solution to maximize the potential of composite materials. However, the composite sandwich structures are prone to damage, such as impact damage and debonding. Although these damages are difficult to detect using conventional nondestructive inspection method, they cause significant reduction in the mechanical properties. Hence, several researchers have attempted to detect and suppress the damages using smart sensors and actuators. In this paper recent developments on smart technologies to improve reliability of the composite sandwich structures are reviewed. First, the state-of-the-art sandwich technology in aerospace application is presented. Next, typical damages in composite sandwich structures are described, which is essential to effectively apply the smart technologies to sandwich structures. Then, smart technologies which have been applied to sandwich structures are briefly shown with focusing specific properties of sandwich structures. It includes damage detection using dynamic response, wave propagation and optical fiber sensors. Finally, a smart honeycomb sandwich concept is also presented. State-of-the-art sandwich technology in aerospace structuresSandwich concept has wide range of advantages and potentials over quasi metal-derived design. Since the facesheets are continuously sustained by the core, the global and local stiffening can be achieved. Moreover, the integral simple stiffening reduces the complexity in analysis, manufacturing and maintenance, resulting in cutting the total life cycle cost of the structure. Introduction of sandwich structures in fuselage shells reduces the noise level inside the cabin, because of high damping properties of the core materials, and thus increases passengers' comfort. In this application, an integration of thermal isolation is also possible.

Latest Developments in Modeling and Characterization of Joining Metal Based Hybrid Materials

“…[15] For example, these composite materials offer many different excellent properties, such as high specific strength, good corrosion resistance, and high electrical and thermal conductivity. [16] Nowadays, cladded materials are used widely in many industries, including automotive, [17] medical, [18] aerospace, [19] chemical and oil refinery. [20] The hybrid metals can be joined using a third medium (e.g., a polystyrene foam) to make a wire-dielectric.…”

Layer-Wise Discontinuous Galerkin Methods for Piezoelectric Laminates

“…The availability of techniques for manufacturing composite laminates employing layers with multi-physics properties has led to the concept of smart laminates, in which different laminae may exhibit couplings between different physical fields, e.g., mechanical, thermal, electric, magnetic or even a combination of more than two of such fields, thus enabling the design of devices with multifunctional capabilities, besides the basic structural employment [2][3][4][5]. A remarkable example is provided by piezoelectric materials and laminates that, exploiting the coupling between the mechanical and electrical fields, may be employed in several applications of engineering or scientific interest [6][7][8][9].…”

Capability of non-destructive techniques in evaluating damage to composite sandwich structures

“…Hence, sandwich structures are extensively used in many aerospace applications nowadays. Regarding the non-destructive testing (NDT), these structures are often more complex, presenting major challenges in some cases (Heida and Platenkamp, 2013;Takeda et al, 2007;Hsu, 2009). Presently, coin tap tests (Prior, 2016) or manual acousto-ultrasonic contact A-scan type methods (pitch-catch (PC)) are still widely used.…”