Simulação numérica de compósitos poliméricos de poli(ácido lático) reforçado com celulose nanofibrilada para aplicações industriais

Abstract

The numerical simulation for stress efforts is an important tool to evaluate the behavior and to predict possible failures and ruptures of mechanical components during its application. It uses the mechanical properties of the material and based on the acting forces and boundary conditions, in a discrete mathematical model of the part, it presents the material's responses in terms of effort absorption, stresses and deformations. The use of nanofibrillated cellulose as a reinforcement in polymeric matrices has been highlighted in recent years in research works, giving rise to composites whose properties can be enhanced and modified according to their applications. Based on this, this work presents the use of numerical simulations as a tool to evaluate and remodel mechanical components constructed from a biodegradable composite, of renewable and recyclable matrix, consisting of nanofibrilated cellulose (NFC), as reinforcement in a matrix of poly(lactic acid) (PLA). An important characteristic for greater versatility in industrial applications, as a mechanical component subjected to efforts, composites must present a good balance between modulus of elasticity and plastic deformation. For this, PLA specimens were produced using NFC as reinforcement by concentrations of 30%, 40% and 50% by weight and with the use of glycerol as a plasticizer, in the proportion of 4% and 6% of the total weight, including a pure PLA sample for comparison. The results of the tensile tests indicated an increase in the plastic deformation without a significant loss in the modulus of elasticity and, consequently, an improvement in the toughness of the material, confirmed by the Izod impact test. Therefore, numerical simulations were carried out via finite element analysis (FEA) to compare the results of the specimen simulations with the results of the physical tensile tests and as a means to evaluate and remodel a mechanical component, constructed with the chosen composite, for replace the current component produced in aluminum alloy 1060 H12 in a tool connected to a robot, in a case study and application in the industry. As a result, a new model was obtained for the component and the technical feasibility in using the composite as a substitute material, presenting advantages such as lower weight and dielectric strength, which are important for the studied application.