Knockdown factors for cylindrical shells caused by torsional Mode-I type geometric imperfections under axial compression

Geometrical imperfection, which is generally a result of manufacturing process and service conditions, plays crucial role in load-bearing capacity shell structures. This study presents numerical on knockdown factors cylindrical shells as torsional Mode-I type geometric imperfections under compressive loads. The deformation patterns obtained from liner bifurcation analysis (LBA) for shape are used source imperfection. Then, geometrically nonlinear buckling with imperfect model (GNIA) incorporated LBA ANSYS Workbench to obtain limit loads A parametric thus performed investigate the influence imperfection depth considering wide range configurations. Local global characteristics examined characterized by three distinct regions basis normalized depth. For large number configurations, scattering against given mathematical expressions evolving lower upper bounds. These provide minimum maximum values depth, can be treated design tool ensure safety structure.