Numerical Simulation And Numerical Models Analysis Of Thoracic Aorta

This paper simulated the thoracic aorta by the linear elastic model with small displacement, the linear elastic model with large displacement, the nonlinear elastic model with large displacement and the nonlinear elastic model with both large displacement and residual stress separately. We analyzed the circumferential stress and displacement of the four models above. The differences between the four models and the experimental result were studied to know which model could simulate the aorta accurately. The arteries were always considered as linear static materials when we dealing with the boundary condition in the simulation analysis of hemodynamics of in-vivo blood vessel. The residual stress of the vessel was merely considered when we simulating the hemodynamics of in-vivo blood vessel. Along with the development of simulation and biomechanics, we should study the problem of hemodynamics with the effect of nonlinear, large displacement and residual stress factors to the arteries. We get some main conclusions from simulation: the displacement of aorta was so large that the geometry nonlinear character can't be ignored; the material nonlinear character can accord with experiment data accurately; residual stress changed the distribution of circumferential stress but it didn't change the level of circumferential stress, the stress distributed along the wall thickness evenly; the expansion ratio wasn't much large; the residual stress didn't influence the displacement of the aorta so the residual stress mustn't be considered when we analyze the hemodynamic problem; the open-angle of the aorta on the state of zero-stress was 15 degrees, the open-angle proved that the method of appling residual stress was credible.The numerical simulation in this paper was an effective method in the analysis of aortic biomechanics. It can be the basic knowledge of calculating complicated vessel models. The hyper-elastic model with residual stress can be used to calculate the problem of vessels which have the bifurcation and the effect of blood. This study can be a reference for the study of blood vessel and blood interaction.