On the helical buckling of anisotropic tubes with application to arteries

• Published in: Mechanics research communications Vol. 128; p. 104067
• Main Authors: Jha, N.K., Moradalizadeh, S., Reinoso, J., Topol, H., Merodio, J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: Helical buckling; Looping; Nonlinear elasticity; Torsional instability; Helical buckling; Looping; Torsional instability; Nonlinear elasticity
• ISSN: 0093-6413
• DOI: 10.1016/j.mechrescom.2023.104067

The helical stability experienced by elastic cylinders is investigated using numerical methods. A doubly fiber-reinforced incompressible nonlinear elastic tube subject to axial loading, internal pressure and twist is examined using a numerical scheme based on the modified Riks (quasi-static) procedure. Under the application of such loadings (qualitatively physiological for arteries) vessels form tortuous shapes and a range of topologically and geometrically complex morphologies. These configurations can be highly unstable owing to the nonlinear interaction (geometry, material and self contact) among the multiple bifurcation modes. The present work attempts to model such complex configurations using a thick-walled cylindrical tube. These complex morphologies are most commonly termed as helical coiling, looping and winding in the biomechanics community. We show that these bifurcations are very sensitive to the applied pressure, axial stretch and the amount of twist. Illustration of the helical buckling is then provided by considering an anisotropic constitutive model that includes both fiber stretching and fiber shearing, as opposed to previous analyses that only consider fiber stretching. The numerical implementation is achieved via user routine in the finite element code Abaqus. •Helical stability experienced by elastic cylinders is investigated.•Fiber-reinforced tubes are subject to axial loading, pressure, and twist.•The modified Riks (quasi-static) procedure is applied.•Under loading, vessels form tortuous shapes and complex morphologies.•Results show: curving, helical buckling, kinking, and looping.