Robust Design Of Imperfection Sensitive Thin-Walled Shells Under Axial Compression, Bending Or External Pressure Draft

•Improved variant of the reduced stiffness method is presented, the localized reduced stiffness method (LRSM).•The LRSM is a versatile and effective lower-bound method for the design of buckling critical thin-walled shells.•Physical explanation for the plateau or lower-bound buckling load of cylinders under axial compression is identified.•The LRSM is applied and validated with experimental results for different shells and different load cases.•The LRSM is easy to implement in commercial finite element codes and delivers 24% to 176% higher KDFs for the buckling load when compared with currently used empirical guidelines.