A multiscale framework for large deformation modeling of RBC membranes

In the present contribution, a multiscale framework for nonlinear analysis of finite deformation of red blood cell (RBC) membrane is developed. The first-order Cauchy-Born rule is adopted to establish an atomistic enriched hyperelastic constitutive model and to develop macroscale stress-strain relation of the RBC membrane. In order to circumvent the inherent limitations of utilizing mesh-based methods for large deformation analysis, we systematically coupled the 3D multiscale scheme with the element-free IMLS-Ritz method for numerical modeling of RBC deformability by simulating the optical tweezers experiment. This development was partly motivated by the need for a more precise scheme for modeling membrane structures. The effectiveness of the proposed approach is affirmed by the better prediction of RBC membrane deformability in comparison with experimental and numerical results found in literature and a significant reduction in computational cost. Our approach enables precise characterization of the effect of varying microstructure parameters, physiological, and osmolality conditions on the deformability of RBC membrane.