Finite element analysis of two-piece cardan shafts using conventional and composite materials

This study investigates the structural and dynamic performance of two-piece cardan shafts manufactured from conventional and advanced materials using finite element analysis. Five shaft configurations were examined: Steel SM45C, Hardox 400, Stainless Steel, HS-Carbon Epoxy-coated steel, and E-Glass Polyester-coated steel. Three-dimensional models were developed in SolidWorks and analyzed in ANSYS Workbench under an applied torque of 1250 N·mm and rotational speed of 2000 rpm. Transient structural analysis was conducted to evaluate total deformation, shear stress, principal stress, strain energy, and elastic strain, while modal analysis was performed to determine vibration characteristics and natural frequencies. Structural results showed very close mechanical responses for all materials, with maximum deformation ranging from 4.2513 × 10⁻⁶ m (Hardox 400) to 4.2895 × 10⁻⁶ m (E-Glass Polyester). Maximum principal stress values were nearly identical, varying between 3.5624 MPa and 3.5648 MPa, confirming adequate structural integrity under the applied loading. Mass comparison based on density demonstrated that HS-Carbon Epoxy and E-Glass Polyester can reduce shaft weight by 78.9% and 72.4%, respectively, relative to steel. Modal analysis revealed that HS-Carbon Epoxy exhibited the highest dynamic stiffness, achieving a sixteenth-mode frequency of 9140.2 Hz, followed by Stainless Steel (8510.7 Hz) and Steel (8802.3 Hz). Hardox 400 displayed lower modal frequencies in the updated analysis, indicating higher vibration sensitivity. Overall, composite-coated shafts offer the best balance between lightweight design and high dynamic performance, while Hardox 400 remains attractive for wear-resistant heavy-duty applications.