Printing imperfections – geometric patterns to improve resistances of 3D printed steel plates

Traditional structural steel manufacturing routes typically produce prismatic members comprising of flat plate elements. Under compressive actions, the capacity of these sections is often dominated by plate instability of the lowest buckling mode. The current study proposes the use of innovative additive manufacturing to produce metallic plate elements with predefined imperfection patterns capable of postponing instability via the lowest buckling mode thus providing increased buckling resistances. To this end, a program of numerical modelling has been carried out to explore various combinations of predefined surface waves with different amplitudes in stainless steel square hollow section stub columns of varying slenderness. Their stiffness, strength, and material consumption against the typical flat sided structural steel members with the same nominal dimensions were assessed. The study identifies the possibility for ‘imperfect’ sections to achieve up to a 50% increase in strength for a minimal increase in material consumption. This innovative study highlights the significant potential of new metallic additive manufacturing technologies in achieving unprecedented material efficiency and economic design in the future steel construction industry.