The scientific field of formulations and discretization methods for thin-walled structures received a new dynamic with the isogeometric concept [1]. In addition to smooth geometry description, smooth splines are particularly attractive in problems for which the weak form has a variational index of 2 or larger, for instance, the Kirchhoff-Love shell model [2]. The approximation power of smooth splines also possesses a potential for effcient and accurate stability analyses of thin-walled structures. Previous studies on pre-buckling of shells [3] show that isogeometric discretizations may provide superior accuracy compared to standard shell finite elements in detecting both critical load factors and buckling modes. Dynamic buckling analyses of thin shells [4] and dynamic wrinkling analyses of thin membranes [5] using isogeometric shell formulations underline the promising properties of smooth splines for nonlinear problems. This contribution discusses the potential of isogeometric discretizations for stability analyses of shell and membrane structures. Previous results from [3] are extended by a systematic and extensive benchmark study involving several shell formulations and varying slenderness ratios. The use of eigenmodes from pre-buckling analyses as geometric imperfections for non-linear static and dynamic stability analyses of thin-walled structures is investigated and critically evaluated. REFERENCES [1] T. J. R. Hughes, J. A. Cottrell, Y. Bazilevs, Isogeometric analysis: CAD, finite elements, NURBS, exact geometry and mesh refinement, Comp Methods Appl Mech Eng, Vol. 194, pp. 4135-4195, 2005. [2] J. Kiendl, K. U. Bletzinger, J. Linhard, and R. W¨uchner, Isogeometric shell analysis with Kirchhoff–Love elements, Comp Methods Appl Mech Eng, Vol. 198(49–52), pp. 3902-3914, 2009. [3] B. Oesterle, F. Geiger, D. Forster, M. Fr¨ohlich and M. Bischoff, A study on the approximation power of NURBS and the significance of exact geometry in isogeometric pre-buckling analyses of shells, Comp Methods Appl Mech Eng, Vol. 397, 115144, 2022. [4] Y. Guo, M. Pan, X. Wei, F. Luo, F. Sun und M. Ruess, Implicit dynamic buckling analysis of thin shell isogeometric structures considering geometric imperfections, Int J Numer Meth Eng, Vol. 124.5, pp. 1055–1088, 2023. [5] T. Burgwedel, A. Seils, S. Reinhart and B. Oesterle, The influence of prestress on the wrinkling behavior of sheared rectangular membranes: First experimental results and transient shell analyses, COMPDYN 2025