Finite Element Nonlinear Analysis Of Aortic Arch

This task comes from the project named"Study on mechanics of aortic dissecting aneurysm"supported by National Nature and Science Fund. Investigation into the the displacement and stress of aortic arch is a hot topic in the field of medicine and biomechanics. It is closely relative to the cardiovascular motion law and the cause of the aortic dissecting aneurysm. Consequently, the investigation into aortic arch especially the displacement and stress of aortic arch made of nonlinear material and geometry is of great significance in theory and practice.The displacement and stress distribution of aortic arch with nonlinear large deformation are studied through FEM in this paper and compared with the linear elastic model. The results are as follows: after large deformation, the sections of bended segment made of nonlinear material along the axes change into the shape of ellipse, and the degree of deformation is highest at the center of section; the displacement of the center of the section on the free end is the largest. While as for the linear elastic model, after small deformation the sections of bended segment along the axes also change into the shape of ellipse, similarly, the degree of deformation is highest at the center of section. In the nonlinear model with artery wall pressed by inner pressure, the largest circumferential stress appears on the section near the descending aorta; the level of circumferential stress is about 250KPa; however, in the linear elastic model with small deformation, the level of circumferential stress is 70KPa. The high level of stress of nonlinear is supposed to be caused by the nonlinear materials. At each section of the nonlinear model, the outer circumferential stress is greater than the inner one along the long axes; however, the situation is on the contrary in the linear elastic model, the reason for which is that the bending stress is greater than tensile stress at the nonlinear curvature.The numerical simulation of mechanics behavior of the aortic arch wall made of nonlinear elastic material is completely studied. Scientific evidence can be provided for studying the mechanical factor of aortic dissecting aneurysm. And it is advantageous for further blood vessel and blood interaction.