Experiment, Simulation, and Design of WAAM Stainless Steel CHS Stub Columns under Axial Compression

This paper presents a comprehensive study of wire arc additively manufactured (WAAM) stainless steel circular hollow section (CHS) stub columns under axial compression, including experimental testing, numerical simulation, and design provision evaluation. Seven CHS stub columns with varying local slenderness were fabricated using WAAM technology. Compression tests revealed that the WAAM specimens slightly underperformed compared with components made of conventionally manufactured steel, attributed to the local geometric imperfections cause by WAAM. To investigate this in detail, a noncontact three-dimensional (3D) laser scanning method was employed to obtain digital geometric models of the WAAM specimens and assess the local geometric imperfections. Two types of finite-element (FE) models were developed and validated: one based on the scanned geometric models and the other using simplified parametric models. The design provisions stipulated by European codes, American codes, Chinese codes, and the continuous strength method (CSM) were evaluated and found inadequate for WAAM CHS columns. Consequently, a new design provision based on the CSM was proposed, demonstrating improved accuracy and safety for predicting the performance of WAAM CHS stub columns.