Application Research on the Lightweight Design and Optimization of Carbon Fiber Reinforced Polymers (CFRP) Floor for Automobile

In order to enhance the mechanical performance of carbon fiber/epoxy resin composites (CF/EPs), a series of γ‐Al2O3 nanosheet/graphene (AG) composites were prepared by hydrothermal method, and successfully introduced into the carbon fiber (CF) surface via self‐assembly process, which significantly improved the interfacial bonding force between CF and EP. Mechanical test results showed that the AG modified CF/EPs exhibited superior properties in interfacial shear strength (IFSS), interlaminar shear strength (ILSS), tensile strengths, and flexural strengths compared with the untreated CF/EPs, which were enhanced by 142.9%, 59.6%, 152.5%, and 40.5%, respectively. This is mainly because AG largely increases the CF surface roughness and penetrates into the matrix to enhance the mechanical interlocking effect, crack deflection effect, and Van der Waals forces between CF and polymer matrix. Briefly, the AG synthesized in this study will provide an experimental validation for the development of high‐performance carbon fiber reinforced polymer composites (CFRPs) and exhibit potential application prospects in automotive and other fields.Highlights Graphene effectively inhibits the agglomeration of γ‐Al2O3 nanosheet. γ‐Al2O3 nanosheet/graphene increases the interfacial properties of CF/EPs. γ‐Al2O3 nanosheet/graphene largely enhances the mechanical performance of CF/EPs. The as‐prepared AGCF/EPs have potential application in automotive and other fields.

Enhanced mechanical performance of carbon fiber reinforced polymer composites by interface modification with self‐assembled γ‐Al₂O₃ nanosheet/graphene

Liu,

Chen,

Gong

et al. 2024

Understanding the compaction behavior of uncured thermoset prepreg: Experimental investigation and theoretical analyses

Yan,

Gong,

Wang

et al. 2024

The deformation behavior of uncured thermoset prepreg during hot compaction process was investigated by dividing the whole compaction process into an initial compression stage and the subsequent creep stage. At the compression stage, there existed a strain‐softening phenomenon in the temperature range of 50–90°C, indicating different deformation behavior that is mainly determined by the viscosity of prepreg. Following an appraisal of advantages and limitations of existing compaction models, a combination model consisted of a modified power‐law model including the influence of temperature and the generalized Kelvin‐Voigt model was proposed to describe the deformation behavior of prepreg during compression and creep stage, respectively. Finally, a discussion on the compaction mechanism was conducted to offer some insights into the deformation process.Highlights Strain‐softening phenomenon occurred during the compaction of uncured prepreg. Proposed combination model captures the deformation of uncured prepreg well. The percolation mechanism dominates prepreg deformation during compaction. The squeeze flow mechanism causes limited thickness reduction of prepreg.

Progressive damage and stiffness degradation assessments of double‐lap CFRP/Ti interference fit bolted joints under quasi‐static tensile load

Zuo,

Wang,

Jiao

et al. 2024

Matrix crack propagation and stiffness degradation behaviors of the carbon fiber reinforced polymer/titanium alloy (CFRP/Ti) bolted joint were characterized by a synergistic damage mechanics approach. The parametric study including pre‐tightening torques and interference fit sizes was conducted. The results showed that the joint stiffness degradation exhibited characteristics of local stiffness degradation due to local stress concentration. Stiffness degradation in different plies was caused by matrix crack damage occurring in different directions. The pre‐tightening torque significantly increased the joint stiffness and restrain matrix crack progression, effectively inhibiting the stiffness degradation of the joint. Moreover, the low interference fit level delayed the crack initiation in −45° ply and 45° ply and the crack propagation of the laminate, while promoted the crack initiation in 90° ply. The stiffness degradation of the laminate could be significantly reduced by interference fit.Highlights Matrix crack propagation and stiffness degradation behaviors of the CFRP laminate were characterized by a synergistic damage mechanics method. A FE model of the CFRP/Ti double‐lap interference fit bolted joint was established. Influences of pre‐tightening torques on both matrix crack initiation and propagation were investigated. The optimum interference fit size of the matrix damage strengthening was 0.20%–0.60%.