Enhancement of mechanical strength of miter joints in pultruded fiberglass/epoxy composite

Abstract In this research, we experimentally investigated how the shape of fittings affects the load-carrying capacity of miter joints in pultruded glass/epoxy composite frames. Specifically, three types of steel fittings – dovetail (D-shaped), H-shaped, and rectangular (U-shaped) were utilized to reinforce the miter joints in composite frames. Tension and compression tests were performed to assess the load-carrying capacity of these joint configurations. Additionally, finite element analysis (FEA) was employed to examine stress distribution patterns within the joint configurations, allowing us to make comparisons among the joint configurations in terms of their strength. The findings of the study demonstrated that all types of joint configurations successfully improved the joint strength, regardless of whether they were subjected to tensile or compressive loading conditions. Notably, H and D type steel fittings exhibited superior effectiveness in strengthening the adhesive miter joints when compared to U type steel fittings, particularly in tensile loading scenarios. Moreover, all types of steel fittings displayed promise as viable options for enhancing joint strength in compressive loading situations.