Michel Bermudez

Metallic Strip Details for Validation of ESN Technologies

The aim of AS10 is to evaluate technologies that can be integrated directly into structures with the target of creating an electrical structural network (ESN) while reducing weight and improving survivability of composite structures. These investigations are based on various technologies and materials from nanomaterials to metallic strips and coatings. The metallic strip concept is based on the merging of materials at macro- and meso-element scale level, using conventional manufacturing technologies. The innovative development consists of a preassembled semi-product composed of an aluminium strip and a nonvulcanized rubber that is cobonded to the composite frame part while curing the structure. This paper presents the metallic strip design and manufacturing choice, the thermomechanical experimentation and modelling conclusion, the impact coupon test results and conclusion on damage tolerance and detectability of impacts, the electrical current distribution simulation and test and finally the electrothermal behaviour results and conclusion.

Experimental results of medium velocity impact tests for reinforced foam core braided composite structures

Absorbing impact energy at subsystem level is an attractive idea that is emphasized by new composite reinforcement techniques such as stitching or pinning. This paper reports experimental results of medium velocity impact tests carried out on several arrangements of reinforced foam/braided composite structures. The tests consisted of a steel ball shot at a velocity of 110 m/s from a gas gun impacting the structures on their leading edge. Post-mortem tomography analysis delivered very rich information which shed light on the damage mechanisms that the composite structures underwent. In addition, two fast-speed cameras were used to derive the energy absorption during the impact. Absorption capabilities were also compared with those of dynamic crushing tests (reported in a companion paper) and some designs clearly exhibited promising behavior as shock absorbers.

Installation of Metallic Strip on CRFP Frames: Assessment of IS13 Mechanical and Electrical Performance

The extended use of CFRP material in airframes led to a loss of the ability to use the aircraft superstructure for electrical tasks such as lightning strike protection, systems bonding and grounding. So, to replace metallic fuselage inherent electrical functions in composite aircrafts, an internal metallic structure called electrical structure network or ESN is introduced. The aim of AS10 is to evaluate technologies that can be integrated directly into structures with the aim of creating an electrical structure network (ESN) whilst reducing weight and improving survivability of composite structures. The innovative development consists of a pre-assembled semi-product composed of an aluminium strip and a non-vulcanized rubber that is co-bounded to the composite frame part early at the manufacturing stage. Evaluations of the technology were done at coupon level to check thermal, mechanical and electrical requirements. This paper presents the activity related to IS13 demonstrator and its damage tolerance and electrical performance assessment. For electrical aspects, a numerical model is built, allowing analysing the impact of strip installation versus current solution with the AD2 cable. Numerical results will have to be confirmed with measurements.