Finite Element Modeling (FEM)

A deeper understanding of the mechanical properties of plant tissues can be achieved by means of numerical models of tissue deformation under various load conditions. One of the important steps before an appropriate analysis with FEM is to create a virtual model of the tested object. The virtual model is defined by its geometry, material properties and boundary conditions such as loads and the type of supports. It is important to create a model with the highest possible degree of accuracy regarding real shape reconstruction; but, on the other hand, the model must be simple enough to allow for efficient calculations. In our preliminary study we tested three different methods for parameterization of plant tissues: vectorization, Voronoi tessellation and ellipse tessellation. We created a micro-scale model of onion epidermis tissueusing FEM. FEM was chosen due to its computational efficiency, flexibility and ability to incorporate geometric nonlinearities. The models were validated against experimental data from a tensile test of real tissue strips. The models demonstrated capabilities of simulating large strains with nonlinear behaviour and produced force-strain curves that closely matched the experimental data. The model revealed the significant influence of tissue structure on micromechanical properties and allowed for the interpretation of tensile test results (force-strain curves) with respect to changes occurring in the structure of the virtual tissue. This proved that qualitative improvement of the results obtained from FEM models of plant tissues is possible due to incorporation of the real microstructure.