Flax and hemp composites: Mechanical characterization and numerical modeling

Nowadays, in the global composites industry, an increasing number of companies are studying high-quality innovative and green solutions, in order to achieve the environmental sustainability goals. In this context, the use of a natural fiber reinforced polymer in the design of structural components needs to be validated through experimental mechanical tests. This study provides an overview of the behaviors of flax/epoxy and hemp/epoxy laminates subjected to tensile, four-point bending, and Low-Velocity Impact (LVI) tests, both from an experimental and numerical point of view. For each type of test, finite element models were simulated using the explicit code LS-DYNA in order to characterize the materials, reproduce the load-displacement plots, and analyze the damage evolution of the laminates. Two different types of mesh modeling were investigated for the models: shell and solid elements. In both cases, a proper contact modeling between layers was carried out to account for delamination phenomena of the material. The results obtained show an agreement between the experimental response and the simulated one, highlighting the possibility of designing and manufacturing structural components in composite material reinforced with natural fibers.