Investigation into a robust finite element model for composite materials

•Beams lack required stiffnesses to model the behavior of composite materials.•Double orthotropic-shell model captured observed experimental flexure behavior.•Modified rule of mixtures was explored to determine accurate material properties.

Two models for completing structural analyses of cured fabric-reinforced composites that link back to a forming simulation are investigated. The objective of each model is to seamlessly use the predicted geometries of the textile plies to generate a finite element model of the cured structure. The first is a beam-shell model, where beam elements represent the fibers and shell elements represent the matrix. The beams are imported directly from the forming model to capture the deformed fabric geometry. The second approach is a double-orthotropic shell model where two shells, each representing a set of fibers, i.e. warp or weft, are superimposed. The material orientation in each shell is aligned with the respective fiber directions. To investigate the capabilities of the models for unidirectional-fiber reinforced composite plates with multiple fiber orientations and loading configurations, the two models are compared to classical laminate theory (CLT). To explore the models׳ ability to represent a plain-weave textile reinforced composite plate with various shear angles in the fabric reinforcements, the two proposed models are compared to experimental data. The double orthotropic shell model is found to be a better option for linking the mechanical behavior of the formed composite back to the simulation of the manufacturing process than the beam-shell model.