Evaluación de propiedades termo mecánicas en materiales alternativos para la fabricación de rejillas de ventilación de vehículos

Abstract

This work focuses on the prototyping and construction of vehicle ventilation grilles using Computer Aided Design (CAD) and additive manufacturing (3D printing), in three materials selected prior to a bibliographic review (PETG, ASA and POLYCARBONATE (PC), which presented the best thermal properties; these prototypes are manufactured at different filling percentages (50 and 100%). The validation of these grilles and materials will be through experimental tests and computer simulation. (CFD) The physical tests were executed in a wind tunnel designed using the ASTM D648 standard for thermal deformation and considering the recommendations of the ISO 11357 standard for differential thermal analysis. The test conditions were replicated for 3 hours, with a constant thermal power of 1500 W. The maximum temperature in 20 vehicles was selected as a reference (49.1 ° C). vehicles, reaching a temperature of 52.7 degrees Celsius before starting to deform; on the other hand, ASA and Polycarbonate (PC) are excellent alternatives for the manufacture of heating elements due to their positive response to prolonged exposure to high temperatures, withstanding temperatures of 75.74 and 84.8 degrees Celsius respectively before beginning to deform. The PETG grid presented a maximum deformation of 8 mm with respect to its original diameter of 71.7 mm, equivalent to more than 10%, being considered unacceptable. In contrast, grids manufactured in ASA and Polycarbonate (PC) maintained their dimensional integrity, presenting deformations less than 2% (between 0.18 and 0.2 mm), which is why they are considered viable for applications in automotive heating systems.