Effect of fiber orientation and layering on shape distortion and mechanical behavior of jute composites

Plant fibers provide a biodegradable and sustainable alternative to synthetic reinforcements in polymer composites. However, process-induced shape distortion, which occurs from the residual stresses produced due to varying thermal expansion and complex interaction between the fiber and resin matrix, is a key problem in their use. This research examines the impact of varying stacking sequences and number of layers on the shape distortion of jute/epoxy composites. Jute yarn was impregnated with epoxy resin to make prepreg sheets. These sheets were stacked at different angles and configurations and consolidated to make flat composite sheet using compression molding. Following the post-curing of these composites, a significant curvature was observed in the flat plates, which was quantified in terms of curvature height and radius of curvature. The tensile properties, thermal conductivity and Coefficient of Thermal Expansion (CTE), of the developed composite materials were also evaluated. The findings revealed that the composite with a stacking sequence of [0/90/0] exhibited enhanced tensile strength, reaching 90.077 MPa. Composite featuring a stacking sequence of [0/90/0/90], exhibited the least curvature height and minimal warpage (0.4 mm in longitudinal and 2.2 mm in transverse direction). Additionally, it also exhibited a value of 3.33 × 10⁻⁶ for CTE and of 0.0283 W/m·K for thermal conductivity.