Research on effects of composite skin on crashworthiness of composite fuselage section

Abstract

Crashworthiness design and certification have been and will continue to be the main concern in aviation safety. The influence of composite skin on crashworthiness of composite fuselage section was investigated in the paper. A finite element model of fuselage section was built, and the dynamic responding characteristics of composite fuselage section subjected to vertical impact velocity of 6.67 m/s were analysed by changing composite ply numbers and ply angles in the explicit finite element code LS-DYNA. The failure modes and acceleration response of fuselage section under different conditions were presented. The results show that the peak overload on the seat can be significantly reduced by selecting appropriate composite ply numbers and ply angles, and the crashworthiness of composite fuselage section can be efficiently improved.

Evaluation on crashworthiness and energy absorption of composite light airplane

“…Many investigations use composite materials to improve the energy absorption capability for various structures as well as civil aircraft fuselage under impact loading. [26][27][28][29][30][31][32][33][34] Many studies have proposed experimental methods for determining the absorbed energy of composite materials using different specimens with different shapes as well as various impact speeds. 16,35 Feindler et al 18 used a compressive rate of 0.25 mm/s to test CFRP specimens in omega-shaped and plate-shaped specimens with three different laminate layups (45°and 0°).…”

Parametric analysis of composite sinusoidal specimens under quasi-static crushing

“…The commercial finite element software codes are developed because of these disadvantages for engineering experiments, such as long design cycles, high costs, poor repeatability, etc. These commercial mainstream codes, such as LS-DYNA, ABAQUS, MSC.Dytran and PAM-CRASH, are available to use for crash simulations of composite aircraft structures (5)(6)(7)(8) , and offer built-in material models for composite structures, and each material model utilises different modelling strategy, which includes failure criterion, degradation scheme, material properties, and usually a set of model-specific input parameters that are typically needed for the computation, but do not have an immediate physical meaning (4) . So, the combination methods of extensive simulations and little experiments, and the establishment and development of simulation analysis method on crashworthiness of composite structures have become important research works.…”

Crashworthiness Analysis and Evaluation of Fuselage Section with Sub-floor Composite Sinusoidal Specimens

“…The finite element model of fuselage section with sub-floor composite sinusoidal specimens was built by using the computer software code HyperMesh (Han, 2007;Zou, 2012;Altair Engineering, 2013;Feng, 2013;Siromani, 2013), due to the aircrafts deformation mainly occured in fuselage sub-floor structure during a crash. The finite element model of fuselage section consisted of skin, fuselage frames, long stringers, oblique struts, floor beams, floor composite sinusoidal specimen, and so on.…”

“…The Netherlands NLR (National Aerospace Laboratory) manufactured the composite sinusoidal specimen, and was responsible for the static tests, the German DLR (Deutsches Zentrum für Luft-und Raumfahrt) was responsible for the dynamic crushing tests, while the France CEAT (Centre d'Essais Aéronautiques de Toulous) carried out the crashworthiness tests of A320 fuselage section with subfloor composite sinusoidal specimens, and eventually put forward a complete set of crashworthy test methods for composite aircraft based on the crashworthiness researches (Wiggenraad, 2001). At the same time, the research institutes and scholars had done a lot of researches of composite aircraft structures with the combination methods of test and simulation with varying degrees of success, for circular tubes (Huang, 2009;Mamalis, 2006) square tubes (Palanivelu, 2010;Xiao, 2009), C channels (Deleo, 2009), and fuselage section (Jackson, 2011;Ilcewicz, 2005;Zou, 2012;Feng, 2013). Based on the "building block" approach of FAA AC 20-107B, amount of experiments, simulation and optimization design studies of cargo subfloor composite C channels were conducted by JAMS (Joint Advanced Materials & Structures Center of Excellence) (Feraboli, 2008;Wade, 2011), the failure process and failure modes of composite C channels can be more accurately simulated by the developed finite element models, the tests and simulation of details, sub-components and components would be further carried out in order to deeply study the crashworthy performance of composite fuselage section.…”

“…The crashworthiness design and verification of composite aircraft structures mainly rely on the engineering experiences combined with extensive tests for a long period of time, but there are some disadvantages for the method, such as the long design cycles, high costs, poor repeatability etc. With the development of commercial finite element software codes, such as LS-DYNA, MSC.Dytran, ABAQUS and PAM-CRASH, an effective way to research the crashworthiness of composite aircraft structures is by using the numerical simulation methods combined with small amount of tests (Damodar, 2005;Feng, 2013;Heimbs, 2013;Wiggenraad, 1999;Xue, 2014;Zou, 2012). Therefore, in order to meet the requirements, the establishment and development of simulation analysis method on crashworthiness of fuselage section has become an important research work.…”