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The standardized lightning current waveform. The direct lightning attachment usually occurs within 0.5 ms, therefore component A of the standardized waveform will be applied in the lightning direct effect study. The transient current of component A can be approximated by using Heidler Function [12],
Contexts in source publication
Context 1
... the natural lightning. Fig.1 depicts the standardized waveform which involves a sequence of four main components: component A (initial strike), component B (intermediate current), component C (continuing current), and component D (re-strike). ...
Context 2
... of 0.93, t1 and t2 are the time- constants. Alternatively, we may simplify the model for transient current by using bi-exponential function. The injection current induced by the lightning strike is thus modeled as an excitation source in the computer simulation. In this paper, the first strike or component A in the typical lightning waveform (Fig. 1) is modeled by using Eq. (1). For instance, with the parameters of, imax is 200 kA, t1 is 19 μs, t2 is 485 μs, n is 10, and k is 0.93, the pulsed waveform of the injection current is derived and illustrated in Fig. ...
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Citations
... Composite material with unique features of light mass, good corrosion and fatigue resistivity, high mechanical stiffness and thermal stability, excellent processability, low tooling cost, and flexible assembly has been increasingly exploited in aerospace engineering [5], [6], [7]. However, the inherent poor electrical conductivity of composite hinders its wide application in aircraft due, in part, to the concerns of EM shielding and lightning protection [8], [9], [10]. ...
... However, it is usually very challenging to acquire the frequency-dependent EM constitutive parameters of both CF and resin matrix from manufacturers or vendors. As an alternative, an equivalent modeling approach based on the measured electrical conductivity is proposed [5], [36]. Since the electrical conductivity of a composite ply is dominated by CF, a unidirectional CFRP (UD-CFRP) composite ply is first measured in three directions (along and across the CF direction, and composite thickness direction) as reference. ...
... The measured effective electrical conductivities along fiber direction, across fiber direction, and through the thickness of composite are 48 192, 284, and 111 S/m, respectively. The direct attachment of lightning on composite is simulated, where the peak value of the lightning source is 200 kA [5]. The current behavior inside the composite is characterized based on the equivalent model generated in Section III. ...
This paper presents a new conductive carbon fiber reinforced polymer (CFRP) aircraft composite and its electromagnetic characterization for tackling the lightning direct effect and enhancing the electromagnetic shielding effectiveness (SE). The CFRP composite design is deliberated for ameliorating the electrical conductivity of composite. With the aid of equivalent medium modeling, the inherent electromagnetic properties of the composite have been investigated. The simulated results illustrate that the lightning strike protection (LSP) capability and the electromagnetic shielding behavior of the newly developed aircraft composite have been improved as compared to the original neat CFRP composite, and comparable to that with copper mesh as a protective layer on top. Moreover, an artificial lightning experiment has been carried out in accordance with SAE ARP5416 by mimicking the natural lightning strike attachment. The shielding effectiveness of the proposed composite prototype has also been measured by using electromagnetic waveguide transmission line method. The physical experiments have effectively validated the simulation results and demonstrated the feasibility of the proposed conductive CFRP composite on LSP and SE.
... The currents produced by a lightning strike, and its generated electromagnetic fields, could produce disturbances in the electronics and processors that make up the avionics systems. This is a major threat in the case of vehicles with composite material structures [5] [6]. In addition, studying lightning effects on CFC structures is crucial, because of the lack of uniformity in the currents inducted in electricity in the different directions [7]. ...
... The currents of a lightning strike and the associated electromagnetic fields generated by them could penetrate inside any aerial platform and could produce disturbances in the electronics and processors that make up the avionics systems. This threat is bigger in the case of vehicles with composite material structures [5,6]. The absence of uniformity in the conduction of electricity in the different directions makes the study of lightning effects on CFC structures especially important [7]. ...
The electromagnetic performance of aerial platforms, which are composed mostly of nonmetallic materials, is a subject of great interest at present time. The behavior of this type of composite structure against electromagnetic environmental effects (E3), such as lightning, is not well-studied as in the case of metalic structures. The purpose of this article is to characterize the joints present in aerial platforms constructed mainly of nonmetallic composite materials. The study of these joints is fundamental because electrical discontinuities or preferential routes can produce changes in the electromagnetic behavior of an aircraft. The proposed measurement system for the characterization of these joints is a microstrip line. The flexibility of the test setup allows for evaluation of different joints in carbon fiber composite (CFC) samples with a different number of plies. Additionally, approximated models of the behavior of the joints as well as the detection of possible defects in the joining process are reported.
... It is known that the aircrafts experience at least one lightning strike in 3000 flight hours [2]. If the energy induced by lightning is over certain level, the CFRP composite might be easily delaminated or pyrolyzed because carbon fiber has thousand times less electrical conductivity than aluminum or copper material [3]. The second concern is the electromagnetic leakage. ...
... When a lightning strikes on the composite (assumed at the centre point of the panel), the current density distribution along the panel thickness is simulated based on the equivalent model. The peak value of lightning source is 200 kA [3]. When more plies with higher conductivity (original value × 1000), more current could quickly scatter to the exit points in these high conductive plies thus the lower plies have much less currents, which is illustrated in Fig. 2. Fig. 3(a). ...
