Influence of stacking configurations on the mechanical characterization of polyester composites reinforced with jute fibers

ABSTRACT

Polymeric composites reinforced with natural fibers stand out as promising alternatives to conventional materials in structural applications, due to their good strength/weight ratio, lower environmental impact and economic viability. This research evaluated the influence of jute fiber orientation on the mechanical properties of composites with terephthalic polyester resin matrix. Four stacking configurations were analyzed: [0°/0°/0°], [0°/45°/0°], [0°/90°/0°] and [0°/fabric/0°]. The plates were manufactured by manual lamination, and specimens were extracted for tensile tests. Aspects such as maximum force, displacement at maximum force, resistance limit and modulus of elasticity were evaluated. Fiberglass composite tabs were selected to ensure the correct application of the load in the tensile tests. The orientation of the fibers directly influenced the mechanical strength. The [0°/0°/0°] configuration obtained the best performance, with a tensile strength of 69.00 MPa, followed by [0°/fabric/0°] (52.42 MPa), [0°/45°/0°] (47.17 MPa) and [0°/90°/0°] (42.31 MPa). The fractographic analysis showed failures due to delamination and crack propagation, which were more intense in the configurations with less fiber alignment with the load direction. Therefore, it was inferred that fiber alignment with the applied stress direction maximizes mechanical strength and can be a fundamental criterion in structural projects that use composite materials.

Keywords:
Natural composites; Hand lay-up; Mechanical strength; Surface fractures