Seleção de fibras naturais como reforço para compósitos da carenagem de um veículo de eficiência energética

Abstract

This work aims to develop the selection of natural fibers as reinforcement for composites in the fairing of an energy-efficient vehicle, using two methods applied to material selection: the TOPSIS multi-criteria method and the original fiber comparison method. The variables of the composite material were restricted, directing the study to the selection of reinforcing fibers and limiting the analysis to fibers of plant origin. The selection criteria were then defined: (i) specific mass, (ii) elastic modulus, (iii) tensile strength, (iv) price, and the maximization or minimization needs related to the selected criteria. The weights for each criterion were defined using the 2-tuple method, with three experienced members of the Pato a Jato team evaluating the importance of each criterion using linguistic variables. Ten natural fibers were selected as alternatives to the glass fiber currently used in the manufacture of the project. Using the TOPSIS classification methods and a comparison with the original fiber, a matrix was obtained representing the ranking of the alternative fibers for each classification method. In the end, using the TOPSIS method, the bamboo fiber was the best performer, showing a similarity coefficient with the ideal solution of 0.777, and using the comparison method with the original fiber, the jute fiber was at the top of the ranking with a similarity coefficient with the original fiber of 0.318. For light applications, where the material is not subject to significant mechanical stress, bamboo and jute fibers represent a sustainable option compared to the glass fiber currently used. Similar analyses could be applied to the proposed model for other contexts involving the selection of natural fibers.