_applied sciences_  
_Article_  
Analysis of Time-Domain Shielding Effectiveness of Lightweight Metallized Carbon Fiber Composite Chassis  
[PERSON] 1, [PERSON] 1, [PERSON] 1, [PERSON] 1, [PERSON] 2 and [PERSON] 2,**  
limit their application in electromagnetic shielding fields, given the need for lightweight shielding chassis. Carbon fiber, with its mechanical robustness and low density, gives it great potential for manufacturing shielded enclosures. Unfortunately, the electromagnetic shielding performance of carbon fiber fails to reach the standard [13; 14]. Recent advancements have illuminated the potential of composite materials to significantly augment the electromagnetic shielding efficacy of structures while preserving the intrinsic properties of the base materials [15; 16; 17; 18; 19]. Noteworthy contributions to this field include the work of [PERSON], [PERSON] et al. [15], who explored the shielding effectiveness of biocarbon-based coatings under varying incidence conditions. Similarly, [PERSON], [PERSON] et al. [16] prepared a flexible and elastic Fe-based amorphous soft magnetic composite for shielding against harmful electromagnetic waves in industrial and military defense applications. [PERSON], [PERSON] et al. [17] investigated the in situ growth of carbon nanotubes on slag using polymer pyrolytic chemical vapor deposition (PP-CVD) to improve the electromagnetic interference shielding of cementitious composites. Further, [PERSON] et al. [18] found that rGO-CF was more effective than CF in improving the electromagnetic interference (EMI) shielding performance of unsaturated polyester-based composites by introducing graphene oxide onto the surface of carbon fibers and then reducing the graphene oxide flakes on the carbon fibers with NaBH4 solution. [PERSON], [PERSON] et al. [19] examined the role of carbon nanotube concentration on the dispersion within polymer matrices and the consequent effects on the shielding capabilities of carbon nanotube-polyolefin composites. These studies fully support the considerable prospects and development potential of composites in the field of electromagnetic shielding. Furthermore, the traditional evaluation of electromagnetic shielding is based on the frequency domain, which provides a standard for evaluating the protective performance of chassis, and electromagnetic shielding technology has developed rapidly under this standard. Yet, the advent of high-power EMP technologies has spotlighted the limitations inherent in frequency-domain analysis, particularly in the context of robust EMP threats. The strong demand for electromagnetic shielding under high-power EMP conditions has led to widespread interest in time-domain shielding effectiveness (TDSE), and this demand highlights the value of time-domain SE (TDSE) analysis, which provides a more detailed characterization of the shielding capability of a chassis under EMP conditions than when assessed using only frequency-domain SE [8]. The significance of TDSE analysis in enhancing our understanding and development of effective shielding solutions cannot be overstated, marking a critical area of research in electromagnetic protection. In conclusion, it is of great importance to develop shielding chassis with both good shielding performance and heat dissipation in aerospace and other areas where lightweight is required. In addition, frequency-domain SE is not sufficient in the analysis of shielding performance under high-power EMP illumination, and time-domain SE should be introduced. To solve the above problems, the following work is conducted in this study:  
1. The development of a nickel-plated carbon fiber composite is introduced, and its electromagnetic parameters (including dielectric constant and permeability) are characterized. 2. A chassis model with holes and slots is established. Then, the electric fields at different observation points inside the three kinds of material (metal, carbon fiber, and nickel-plated carbon fiber) chassis are analyzed by the time-domain difference (FDTD) method.