A nonlinear material description in a 100,000 degrees of freedom finite element model yielded higher displacement vectors compared to a linear elastic model, despite comparable stress distributions.
Incorporating nonlinear material properties in cardiac finite element models yields higher displacement vectors than linear models, highlighting the importance of nonlinear effects in understanding heart mechanics.
The determination of characteristic cardiac parameters, such as displacement, stress and strain distribution are essential for an understanding of the mechanics of the heart. The calculation of these parameters has been limited until recently by the use of idealised mathematical representations of biventricular geometries and by applying simple material laws. On the basis of 20 short axis heart slices and in consideration of linear and nonlinear material behaviour we have developed a FE model with about 100,000 degrees of freedom. Marching Cubes and Phong's incremental shading technique were used to visualise the three dimensional geometry. In a quasistatic FE analysis continuous distribution of regional stress and strain corresponding to the endsystolic state were calculated. Substantial regional variation of the Von Mises stress and the total strain energy were observed at all levels of the heart model. The results of both the linear elastic model and the model with a nonlinear material description (Mooney-Rivlin) were compared. While the stress distribution and peak stress values were found to be comparable, the displacement vectors obtained with the nonlinear model were generally higher in comparison with the linear elastic case indicating the need to include nonlinear effects.
Schmid et al. (Tue,) reported a other. Nonlinear material description (Mooney-Rivlin) FE model vs. Linear elastic model was evaluated on Displacement, stress, and strain distribution. A nonlinear material description in a 100,000 degrees of freedom finite element model yielded higher displacement vectors compared to a linear elastic model, despite comparable stress distributions.