An engineering vision about composite sandwich structures analysis

Abstract

As shown in the literature, there is plentiful information about sandwich panels. Two of the most common points under discussion are the failure modes and the efficiency of numerical simulations considering the stiffness and interlaminar stress. The failure modes in the literature are not always likely to happen in practice, and representing them becomes a challenging task. Regarding the numerical simulations, new assumptions and formulations appear in order to consider the shear stress in the honeycomb CORE and to minimize processing time in 3D models. Although new mathematical solutions emerge, in some cases they are unpractical for engineering applications and must be evaluated and compared with test results in order to verify their consistency. Therefore, experimental results are necessary to validate theories to comply with the failure modes observed in sandwich panels and to validate the finite element model. Also, the main focus of the literature is on the theoretical formulation and not in engineering applications. In this sense, the main contribution of this paper is to bring forward experimental results of aeronautical sandwich panels whose data are scarce and therefore contributes to the validation of new developments. In addition, the purpose of this work contributes to the use of the finite element models with composite sandwich panels where the appropriate input for 2D (plate) and 3D (solid) elements is unclear. It should be pointed out that for failure investigation the first step is validating the finite element model. In this sense, a typical aircraft panel with experimental results is presented. The finite element model and the input parameters that are not mentioned in the classical literature are also presented. The experimental strain from specimen tested agreed well with the numerical simulations results.

Detection of Composites and Sandwich Structures for Aeronautic Application

“…However, other from acknowledging the much greater inspection problem in the literature that has been published for all standard NDT, little effort has been dedicated to the test of thick period composites. These structures' methods [23]. In addition, composites may become internally flawed either during production or use.…”

Composites sandwich structures certification: A case study

“…Therefore, the test machine load was adjusted until the correct load level was reached for the determined strain. In Arakaki and Faria, 13 the finite element model of the test article was validated with the strain experimental results.

Figure 12.Strain in strain-gages region with ramp critical strain.

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Experimental and statistical investigation of the three-point bending strength of the composite sandwich beams with trapezoidal core

“…The use of sandwich beams in new industries has expanded widely in recent years, especially in structures such as ships, aircraft fuselage, cars, and bridges due to their superior static and dynamic resistance despite being lightweight 8–10 . Sandwich structures are formed by bonding top and bottom face sheets onto a lower-performance core.…”