M-204 Materials
Electric Surfboard Factor of Safety
A Machine Design fatigue analysis of the fiberglass-epoxy shell for an electric jet-driven surfboard.
Structural Model
Modeled the 2.413 m surfboard as a simply supported beam with rider, board, and propulsion-unit loads. Beam superposition produced a governing bending moment of 477 N·m and negligible deflection.
Material Testing
Used four-point bending and tensile testing of the fiberglass-epoxy layup to establish a measured ultimate tensile strength of 91.93 MPa for the fatigue model.
Conservative Method
Applied conservative Marin endurance factors, full notch sensitivity, and stress concentrations for the propulsion cutout because composite fatigue and notch data were limited.
Fatigue Result
The shell achieved factors of safety of 22.21 using DE-Gerber and 21.82 using DE-Goodman, showing substantial fatigue margin under the defined bending and torsional loads.