Flax fibers show potential in bio-efficiency compared to conventional composite fibers with good mechanical properties. The tensile behavior of flax fibers shows a nonlinear stress-strain relation. Within this work, a bilinear elastic-plastic approach is described, which is based on the generalized Hill potential theory and easily applicable in ANSYS. The method was used to model the nonlinear stress-strain behavior under quasi-static tensile loading of flax fiber-reinforced laminates. Hashin failure mechanisms using the stress-strain data of the bilinear model are applied as well. The results were compared to experimental data, carried out using pre-impregnated flax fibers in three types of tensile test specimens. The layups of investigation were The strain was evaluated using the non-contact, digital image correlation measurement ARAMIS. Good agreement with the test results was achieved, and the method of bilinear elastic-plastic modeling of flax fiber-reinforced structures was evaluated as simple but effective for quasi-static elongation under uniaxial tensile loading.