Isogeometric Shell Analysis of the Human Abdominal Wall

In this paper, a nonlinear isogeometric Kirchhoff–Love shell model of the human abdominal wall is proposed. Its geometry is based on in vivo measurements obtained from a polygon mesh that is transformed into a NURBS surface, and then used directly for the finite element analysis. The passive response of the abdominal wall model under uniform pressure is considered. A hyperelastic membrane model based on the Gasser–Ogden–Holzapfel tissue model is used together with the Koiter bending model to describe the material behavior. Due to the mixed material formulation, different sets of constitutive parameters are examined such that the influence of each term is analyzed. The membrane contribution of the material model has a major influence on the displacement magnitude and reflects more reliably the nonlinear character of the deformation.