Editorial for the Special Issue on Carbon Fiber Composites III

Composites, which combine two or more components to produce a product with properties superior to those of their individual parts, have played a critical role in modern materials science and engineering [1]. Typically, composites consist of a reinforcing material (e.g., fibers, nanoparticles, etc.) embedded within a matrix (e.g., polymer, metal, ceramic, etc.) [2,3]. Among various reinforced materials, carbon fibers have attracted tremendous attention since they are extremely strong, light, durable, and resistant to environmental damage [4,5]. Because of these advantages, carbon fiber composites have been widely used in the aerospace, automotive, construction, and renewable energy industries, where performance, efficiency, and reliability are paramount [6,7]. Additionally, composites offer design flexibility that allows engineers to customize material properties for specific applications via adapting the proper approaches (e.g., the orientation of fiber fillers, curing conditions, surface modification, etc.) [8,9,10].

This Special Issue brings together studies on the design, preparation, characterization, and applications of carbon fiber composites, aiming to serve as a reference in the field by offering insights into current challenges and future research directions.

Blythe et al. studied the influence of fiber orientation and explored the random effect on longitudinal misalignment via precision fiber laying of unidirectional fabrics [11]. The fiber alignment scatter was reduced by 52% using Fill Multilayer, and the increased fiber orientation resulted in a higher flexural strength of 16.08%. Zheng et al. utilized the energy conversion principle to investigate the damage mechanism of carbon fiber-reinforced concrete [12]. They tuned the strain rates to establish an energy-based damage model, which could be used as a reference for future applications. To address the failure at the interface between the surface material and the ribs, Tanaka et al. introduced a resin layer to the rib roots when the ribs were injected, providing outstanding specific stiffness [13]. Other components, such as wedge anchorages, have prevented carbon fiber composite stress concentration and premature failure [14].

The rotational speed and grinding head design remarkably affect the machining quality, efficiency, and finishing performance [15]. The mesh size and rotational speed were studied to understand their effects on the post-machining quality of carbon fiber-reinforced polymer laminates. In addition, the surface quality of face milling parameters in the 3D-printed version was investigated [16]. Moreover, a uniform layer of graphene oxide/chitin nanocrystals was prepared by Abdel-Mohsen et al. to minimize delamination resistance [17]. On the other hand, Kocharla et al. introduced crab shell powder into the jute/carbon fiber composite [18]. Their results indicate that the composite could achieve its best mechanical properties with 5 wt.% card shell powder thanks to its well-bonded interface between the fiber and matrix.

Surface texturing was also applied by Liu et al. to strengthen metal–carbon fiber-reinforced composite joints [19]. The effects of the corresponding surface morphology and roughness on the properties were studied. In another study, Li et al. proposed using a digital image correlation analysis to research the in-plane shear behavior and process influence on composite performance [20]. Combining carbon fiber-reinforced polymer bars and warps enhanced the reinforced concrete beams, which showed a 95% increment in flexural load capacity compared to the control sample [21].

As discussed earlier, process parameters also play a crucial role in determining the performance of the resulting carbon fiber composites. Bianchi et al. adapted a filament winding process to study the effect of heat-shrinkable tape application on composite mechanical properties, which improved the performance of the wound part because of the enhanced material compaction [22]. In addition, Mandal et al. utilized aromatic vitrimers to boost the processing and self-healing capability of carbon fiber composites [23]. A high-energy laser was introduced to explore the degradation of prepared carbon fiber-reinforced polymer composites [24]. This work proved the predictions concerning the scalable effects of high-energy laser radiation and material behavior in high-performance settings.

In addition to these experimental studies, the finite element analysis (FEA) approach was used to analyze prepared composites. For instance, Han et al. used FEA to evaluate the buckling performance of carbon and/or E-glass fiber-reinforced composite stiffened panels with various skin layups, showing that hybrid reinforcement could optimize structural efficiency and reduce costs [25]. In addition, Ceddia et al. compared carbon fiber-reinforced polymer composite (CFRPC) and Ti-6Al-4V via FEA, indicating that CFRPC exhibited mechanical properties that were close to those of bone, enabling more patient-specific implant designs [26].

Despite extensive research on carbon fiber composites from various perspectives, significant challenges remain. This Special Issue aims to help advance technology, inspire further research, and promote border applications of carbon fiber composites.