Strain analysis in a 3D printed car brake pedal by numerical and experimental methods

Abstract This paper presents the strain analysis in a brake pedal manufactured by additive technologies. A commercial plastic pedal made by injection moulding was optically scanned using a scanning system based on fringes projection. The result was a CAD model of the pedal that can be used in both numerical simulations and 3D printing. Two models of the pedal with 100% infill rate and a grid infill pattern were produced by 3D printing on an industrial printer, the difference between the two models is laying in the orientation of the printed part in the printer workspace. Resistive strain gauges were applied to determine the mechanical behaviour of the printed pedals regarding the injection moulded version. To perform a comparative study of the experimentally obtained results, pedals with similar mechanical characteristics to those measured experimentally were analysed numerically by the finite element method. The numerical results showed a good convergence with the experimental results, with relative deviations of 13% for the printed pedal with outer filaments oriented longitudinally to its longitudinal axis, 7.3% for the printed pedal with outer filaments oriented transversely and 2.8% for the homogeneous (injected) pedal. The results also demonstrated the possibility of replacing in the future complex, parts made today by conventional technologies with 3D printed elements having mechanical characteristics allowing them to fulfil a functional role.