Carbon/basalt hybrid composite bolted joint for improved bearing performance and cost efficiency

In this study, the bearing performance and cost efficiency of single-lap, single-bolt joint of carbon/basalt hybrid composite were assessed. Two non-hybrid laminate joints (pure basalt fiber and carbon fiber laminate joints), and four hybrid laminate joints (two with sandwich-like stacking sequences and two with non-sandwich-like stacking sequences) were fabricated using a vacuum-assisted resin transfer molding process. In comparison to pure carbon-based joints, the hybrid arrangement of basalt layers sandwiched between carbon layers demonstrated improved mechanical performance (23.4% increase in energy absorption and 4.7% increase in ultimate load) while saving 45% of the cost. The surface morphology of damaged specimens was studied by scanning electron microscopy (SEM) at various stages of the loading process. SEM imaging revealed that the proposed hybrid scheme exhibited shear failure, in contrast to all other hybrid designs, which showed interlaminar failure. This study exhibited a better hybrid laminate joint in terms of performance and cost efficiency; which encourages the use of composites in mid/low-end load-bearing applications.